diff --git a/.gitignore b/.gitignore
index 0c9f941a97..cafb205f72 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,6 +12,8 @@ src/physics/silhs
 src/chemistry/geoschem/geoschem_src
 src/physics/pumas
 src/physics/pumas-frozen
+src/physics/rrtmgp/data
+src/physics/rrtmgp/ext
 src/dynamics/fv3/atmos_cubed_sphere
 libraries/FMS
 libraries/mct
diff --git a/Externals_CAM.cfg b/Externals_CAM.cfg
index 3b9952f6e9..debf4c613e 100644
--- a/Externals_CAM.cfg
+++ b/Externals_CAM.cfg
@@ -86,5 +86,19 @@ repo_url = https://github.com/ESCOMP/HEMCO_CESM.git
 required = True
 externals = Externals_HCO.cfg
 
+[rte-rrtmgp]
+local_path = src/physics/rrtmgp/ext
+protocol = git
+repo_url = https://github.com/earth-system-radiation/rte-rrtmgp.git
+tag = v1.7
+required = True
+
+[rrtmgp-data]
+local_path = src/physics/rrtmgp/data
+protocol = git
+repo_url = https://github.com/earth-system-radiation/rrtmgp-data.git
+tag = v1.8
+required = True
+
 [externals_description]
 schema_version = 1.0.0
diff --git a/bld/build-namelist b/bld/build-namelist
index 5ebe186a76..0c56fff055 100755
--- a/bld/build-namelist
+++ b/bld/build-namelist
@@ -694,6 +694,23 @@ my $rad_pkg = $cfg->get('rad');
 if ($rad_pkg eq 'camrt') {
     add_default($nl, 'absems_data');
 }
+elsif ($rad_pkg =~ m/rrtmgp/) {
+    # Dataset for gas optics are checked out of an external repo into
+    # the source code directory.  The paths to this data are relative
+    # to the root directory of the cam component.
+    my $cam_dir = $cfg->get('cam_dir');
+
+    add_default($nl, 'rrtmgp_coefs_lw_file');
+    my $rel_path = $nl->get_value('rrtmgp_coefs_lw_file');
+    my $abs_path = quote_string(set_abs_filepath($rel_path, $cam_dir));
+    # Overwrite the relative pathname with the absolute pathname in the namelist object
+    $nl->set_variable_value('radiation_nl', 'rrtmgp_coefs_lw_file', $abs_path);
+
+    add_default($nl, 'rrtmgp_coefs_sw_file');
+    $rel_path = $nl->get_value('rrtmgp_coefs_sw_file');
+    my $abs_path = quote_string(set_abs_filepath($rel_path, $cam_dir));
+    $nl->set_variable_value('radiation_nl', 'rrtmgp_coefs_sw_file', $abs_path);
+}
 
 # Solar irradiance
 
@@ -705,15 +722,20 @@ if (defined $nl->get_value('solar_const') and
 
 }
 
-if ($rad_pkg eq 'rrtmg' or $chem =~ /waccm/) {
+if ($rad_pkg =~ /rrtmg/ or $chem =~ /waccm/) {
 
    if (defined $nl->get_value('solar_const')) {
-      die "$ProgName - ERROR: Specifying solar_const with RRTMG or WACCM is not allowed.\n"
+      die "$ProgName - ERROR: Specifying solar_const with RRTMG/RRTMGP or WACCM is not allowed.\n"
    }
 
    # use solar data file as the default for rrtmg and waccm_ma
    add_default($nl, 'solar_irrad_data_file');
-   add_default($nl, 'solar_htng_spctrl_scl', 'val'=>'.true.');
+
+   # This option only used by camrt and rrtmg radiation schemes.
+   # The solar spectral scaling is done internal to RRTMGP code.
+   if ($rad_pkg ne 'rrtmgp') {
+       add_default($nl, 'solar_htng_spctrl_scl', 'val'=>'.true.');
+   }
 
 }
 elsif (!$simple_phys) {
@@ -843,7 +865,6 @@ if ($chem_rad_passive or $aqua_mode) {
 
 # The aerosol optics depend on which radiative transfer model is used due to differing
 # wavelength bands used.
-my $rrtmg = $rad_pkg eq 'rrtmg' ? 1 : 0;
 
 # @aero_names contains the names of the entities (bulk aerosols and modes)
 # that are externally mixed in aerosol optics calculation.  These entities are all
@@ -1121,7 +1142,7 @@ if ($aer_model eq 'mam' ) {
   }
 
   if ($rad_prog_sslt) {
-    if ($rrtmg) {
+    if ($rad_pkg =~ /rrtmg/) {
         push(@aero_names, "SSLT01", "SSLT02", "SSLT03", "SSLT04");
         push(@aerosources, "A:", "A:", "A:", "A:" );
     } else {
@@ -1129,7 +1150,7 @@ if ($aer_model eq 'mam' ) {
         push(@aerosources, "N:", "N:");
     }
   } elsif ($moz_aero_data =~ /$TRUE/io ) {
-    if ($rrtmg) {
+    if ($rad_pkg =~ /rrtmg/) {
         push(@aero_names, "sslt1", "sslt2", "sslt3", "sslt4");
         push(@aerosources, "N:", "N:", "N:", "N:" );
     } else {
@@ -1224,7 +1245,7 @@ if ($carma eq 'bc_strat') {
     }
 }
 
-if ($rrtmg) {
+if ($rad_pkg eq 'rrtmg') {
 
   # CARMA Microphysics - RRTMG Only
   #
@@ -1644,11 +1665,25 @@ if ($rad_pkg ne 'none') {
 }
 
 # Cloud optics
-if ($rrtmg) {
+if ($rad_pkg =~ m/rrtmg/) { # matches both rrtmg and rrtmgp
     add_default($nl, 'liqcldoptics');
     add_default($nl, 'icecldoptics');
     add_default($nl, 'liqopticsfile');
     add_default($nl, 'iceopticsfile');
+
+    # rrtmgp only implemented with mitchell and gammadist cloud optics
+    if ($rad_pkg =~ m/rrtmgp/) {
+        my $liqcldoptics = $nl->get_value('liqcldoptics');
+        if ($liqcldoptics !~ m/gammadist/) {
+            die "$ProgName - ERROR: RRTMGP only implemented with gammadist liquid cloud optics\n" .
+                "liqcldoptics = $liqcldoptics\n";
+        }
+        my $icecldoptics = $nl->get_value('icecldoptics');
+        if ($icecldoptics !~ m/mitchell/) {
+            die "$ProgName - ERROR: RRTMGP only implemented with mitchell ice cloud optics\n" .
+                "icecldoptics = $icecldoptics\n";
+        }
+    }
 }
 
 # Volcanic Aerosol Mass climatology dataset
diff --git a/bld/config_files/definition.xml b/bld/config_files/definition.xml
index 7f3ed23873..03f2f10405 100644
--- a/bld/config_files/definition.xml
+++ b/bld/config_files/definition.xml
@@ -91,9 +91,9 @@ on Mapes and Neale (2011): 0 => no, 1 => yes
 PBL package: uw (University of Washington), hb (Holtslag and Boville), hbr
  (Holtslag, Boville, and Rasch), clubb_sgs, spcam_sam1om, spcam_m2005, none.
 </entry>
-<entry id="rad" valid_values="rrtmg,camrt,none" value="">
+<entry id="rad" valid_values="rrtmgp,rrtmg,camrt,none" value="">
 Radiative transfer calculation:
-camrt (CAM3 and CAM4 RT package), rrtmg (RRTMG package from AER).
+camrt (CAM3 and CAM4 RT package), rrtmg (RRTMG package from AER), rrtmgp (updated version).
 </entry>
 <entry id="carma" valid_values="none,bc_strat,cirrus,cirrus_dust,dust,meteor_impact,meteor_smoke,mixed_sulfate,pmc,pmc_sulfate,sea_salt,sulfate,tholin,test_detrain,test_growth,test_passive,test_radiative,test_swelling,test_tracers,test_tracers2" value="none">
 CARMA sectional microphysics:
diff --git a/bld/configure b/bld/configure
index 7ec8b13833..974c30dc5e 100755
--- a/bld/configure
+++ b/bld/configure
@@ -103,7 +103,7 @@ OPTIONS
      -prog_species <list>Comma-separate list of prognostic mozart species packages.
                         Currently available: DST,SSLT,SO4,GHG,OC,BC,CARBON16
      -psubcols <n>      Maximum number of sub-columns in a run - set to 1 if not using sub-columns (default)
-     -rad <name>        Specify the radiation package [rrtmg | camrt]
+     -rad <name>        Specify the radiation package [rrtmg | rrtmgp | rrtmgp_gpu | camrt]
      -silhs             Switch on SILHS.
      -spcam_clubb_sgs   Turn on the SPCAM version of CLUBB
      -spcam_nx <n>      SPCAM x-grid. - defaults to 4 (note the CRM requires spcam_nx to be greater than or equal to 4)
@@ -1069,8 +1069,16 @@ elsif ($phys_pkg =~ m/^cam[56]$|^cam_dev$|^spcam_m2005$/) {
     $rad_pkg = 'rrtmg';
 }
 # Allow the user to override the default via the commandline.
+my $use_rrtmgp_gpu = 0;
 if (defined $opts{'rad'}) {
     $rad_pkg = lc($opts{'rad'});
+    # If the radiation package is set to rrtmgp_gpu then will add the gpu code version
+    # (openmp and openacc) to the Filepath file, but strip off the "_gpu" when setting
+    # the radiation package name in the config_cache file.
+    if ($rad_pkg eq 'rrtmgp_gpu') {
+        $use_rrtmgp_gpu = 1;
+        $rad_pkg = 'rrtmgp';
+    }
 }
 
 # consistency checks...
@@ -1083,13 +1091,18 @@ if ($rad_pkg eq 'camrt') {
             "                 with aerosol package $chem_pkg\n";
     }
 }
-elsif ($rad_pkg eq 'rrtmg') {
+elsif ($rad_pkg =~ m/rrtmg/) {
 
     # The rrtmg package doesn't work with the CAM3 prescribed aerosols
     if ($phys_pkg eq 'cam3') {
         die "configure ERROR: radiation package: $rad_pkg is not compatible\n".
             "                 with physics package $phys_pkg\n";
     }
+
+    # RRTMGP not currently working with CARMA
+    if ($rad_pkg eq 'rrtmgp' and $carma_pkg ne 'none') {
+        die "configure ERROR: The CARMA microphysics package does not currently work with RRTMGP\n";
+    }
 }
 
 $cfg_ref->set('rad', $rad_pkg);
@@ -1125,7 +1138,7 @@ if ($phys_pkg eq 'spcam_sam1mom') {
 }
 
 if ($phys_pkg eq 'spcam_m2005') {
-   if ($rad_pkg ne 'rrtmg') {
+   if ($rad_pkg !~ m/rrtmg/) {
         die "configure ERROR: radiation package: $rad_pkg is not compatible\n".
             "                 with m2005 -- it should be rrtmg\n";
   }
@@ -2231,6 +2244,19 @@ sub write_filepath
     elsif ($rad eq 'camrt') {
         print $fh "$camsrcdir/src/physics/camrt\n";
     }
+    elsif ($rad eq 'rrtmgp') {
+        print $fh "$camsrcdir/src/physics/rrtmgp\n";
+        print $fh "$camsrcdir/src/physics/rrtmgp/ext/extensions\n";
+        print $fh "$camsrcdir/src/physics/rrtmgp/ext/gas-optics\n";
+        print $fh "$camsrcdir/src/physics/rrtmgp/ext/rrtmgp-frontend\n";
+        print $fh "$camsrcdir/src/physics/rrtmgp/ext/rte-frontend\n";
+        if ($use_rrtmgp_gpu) {
+            print $fh "$camsrcdir/src/physics/rrtmgp/ext/rrtmgp-kernels/accel\n";
+            print $fh "$camsrcdir/src/physics/rrtmgp/ext/rte-kernels/accel\n";
+        }
+        print $fh "$camsrcdir/src/physics/rrtmgp/ext/rrtmgp-kernels\n";
+        print $fh "$camsrcdir/src/physics/rrtmgp/ext/rte-kernels\n";
+    }
 
     if ($clubb_sgs) {
        print $fh "$camsrcdir/src/physics/clubb/src/CLUBB_core\n";
diff --git a/bld/namelist_files/namelist_defaults_cam.xml b/bld/namelist_files/namelist_defaults_cam.xml
index d2e028a388..5afa8a0155 100644
--- a/bld/namelist_files/namelist_defaults_cam.xml
+++ b/bld/namelist_files/namelist_defaults_cam.xml
@@ -459,6 +459,36 @@
 <bam_SSLTA  rad="rrtmg">atm/cam/physprops/ssam_rrtmg_c080918.nc</bam_SSLTA>
 <bam_SSLTC  rad="rrtmg">atm/cam/physprops/sscm_rrtmg_c080918.nc</bam_SSLTC>
 
+<!-- Bulk aerosols for RRTMGP -->
+<bam_sulf   rad="rrtmgp">atm/cam/physprops/sulfate_rrtmg_c080918.nc</bam_sulf>
+<bam_SO4    rad="rrtmgp">atm/cam/physprops/sulfate_rrtmg_c080918.nc</bam_SO4>
+<bam_dust1  rad="rrtmgp">atm/cam/physprops/dust1_rrtmg_c080918.nc</bam_dust1>
+<bam_DST01  rad="rrtmgp">atm/cam/physprops/dust1_rrtmg_c080918.nc</bam_DST01>
+<bam_dust2  rad="rrtmgp">atm/cam/physprops/dust2_rrtmg_c080918.nc</bam_dust2>
+<bam_DST02  rad="rrtmgp">atm/cam/physprops/dust2_rrtmg_c080918.nc</bam_DST02>
+<bam_dust3  rad="rrtmgp">atm/cam/physprops/dust3_rrtmg_c080918.nc</bam_dust3>
+<bam_DST03  rad="rrtmgp">atm/cam/physprops/dust3_rrtmg_c080918.nc</bam_DST03>
+<bam_dust4  rad="rrtmgp">atm/cam/physprops/dust4_rrtmg_c080918.nc</bam_dust4>
+<bam_DST04  rad="rrtmgp">atm/cam/physprops/dust4_rrtmg_c080918.nc</bam_DST04>
+<bam_bcar1  rad="rrtmgp">atm/cam/physprops/bcpho_rrtmg_c080918.nc</bam_bcar1>
+<bam_CB1    rad="rrtmgp">atm/cam/physprops/bcpho_rrtmg_c080918.nc</bam_CB1>
+<bam_bcar2  rad="rrtmgp">atm/cam/physprops/bcphi_rrtmg_c080918.nc</bam_bcar2>
+<bam_CB2    rad="rrtmgp">atm/cam/physprops/bcphi_rrtmg_c080918.nc</bam_CB2>
+<bam_ocar1  rad="rrtmgp">atm/cam/physprops/ocpho_rrtmg_c080918.nc</bam_ocar1>
+<bam_OC1    rad="rrtmgp">atm/cam/physprops/ocpho_rrtmg_c080918.nc</bam_OC1>
+<bam_ocar2  rad="rrtmgp">atm/cam/physprops/ocphi_rrtmg_c080918.nc</bam_ocar2>
+<bam_OC2    rad="rrtmgp">atm/cam/physprops/ocphi_rrtmg_c080918.nc</bam_OC2>
+<bam_sslt1  rad="rrtmgp">atm/cam/physprops/seasalt1_rrtmg_c080918.nc</bam_sslt1>
+<bam_SSLT01 rad="rrtmgp">atm/cam/physprops/seasalt1_rrtmg_c080918.nc</bam_SSLT01>
+<bam_sslt2  rad="rrtmgp">atm/cam/physprops/seasalt2_rrtmg_c080918.nc</bam_sslt2>
+<bam_SSLT02 rad="rrtmgp">atm/cam/physprops/seasalt2_rrtmg_c080918.nc</bam_SSLT02>
+<bam_sslt3  rad="rrtmgp">atm/cam/physprops/seasalt3_rrtmg_c080918.nc</bam_sslt3>
+<bam_SSLT03 rad="rrtmgp">atm/cam/physprops/seasalt3_rrtmg_c080918.nc</bam_SSLT03>
+<bam_sslt4  rad="rrtmgp">atm/cam/physprops/seasalt4_rrtmg_c080918.nc</bam_sslt4>
+<bam_SSLT04 rad="rrtmgp">atm/cam/physprops/seasalt4_rrtmg_c080918.nc</bam_SSLT04>
+<bam_SSLTA  rad="rrtmgp">atm/cam/physprops/ssam_rrtmg_c080918.nc</bam_SSLTA>
+<bam_SSLTC  rad="rrtmgp">atm/cam/physprops/sscm_rrtmg_c080918.nc</bam_SSLTC>
+
 <!-- CAM-Chem modal aerosols (different names used in prescribed and prognostic modes) -->
 <!-- Optics for RRTMG -->
 <!-- modal aerosol properties files -->
@@ -471,6 +501,16 @@
 <mam_dst  rad="rrtmg">atm/cam/physprops/dust_aeronet_rrtmg_c141106.nc</mam_dst>
 <mam_nh4  rad="rrtmg">atm/cam/physprops/sulfate_rrtmg_c080918.nc</mam_nh4>
 
+<!-- Modal aerosol properties for RRTMGP -->
+<mam_so4  rad="rrtmgp">atm/cam/physprops/sulfate_rrtmg_c080918.nc</mam_so4>
+<mam_pom  rad="rrtmgp" mam="3mode">atm/cam/physprops/ocpho_rrtmg_c101112.nc</mam_pom>
+<mam_pom  rad="rrtmgp">atm/cam/physprops/ocpho_rrtmg_c130709.nc</mam_pom>
+<mam_soa  rad="rrtmgp">atm/cam/physprops/ocphi_rrtmg_c100508.nc</mam_soa>
+<mam_bc   rad="rrtmgp">atm/cam/physprops/bcpho_rrtmg_c100508.nc</mam_bc>
+<mam_ncl  rad="rrtmgp">atm/cam/physprops/ssam_rrtmg_c100508.nc</mam_ncl>
+<mam_dst  rad="rrtmgp">atm/cam/physprops/dust_aeronet_rrtmg_c141106.nc</mam_dst>
+<mam_nh4  rad="rrtmgp">atm/cam/physprops/sulfate_rrtmg_c080918.nc</mam_nh4>
+
 <!-- Eruptive volcanic aerosols  -->
 <VOLC_MMR                        rad="camrt">atm/cam/physprops/volc_camRT_byradius_sigma1.6_c130724.nc</VOLC_MMR>
 <VOLC_MMR chem="none"            rad="camrt">atm/cam/physprops/sulfuricacid_cam3_c080918.nc</VOLC_MMR>
@@ -479,6 +519,12 @@
 <VOLC_MMR2 rad="rrtmg">atm/cam/physprops/volc_camRRTMG_byradius_sigma1.6_mode2_c210211.nc</VOLC_MMR2>
 <VOLC_MMR3 rad="rrtmg">atm/cam/physprops/volc_camRRTMG_byradius_sigma1.2_mode3_c210211.nc</VOLC_MMR3>
 
+<!-- Eruptive volcanic aerosols for RRTMGP -->
+<VOLC_MMR rad="rrtmgp">atm/cam/physprops/volc_camRRTMG_byradius_sigma1.6_c130724.nc</VOLC_MMR>
+<VOLC_MMR1 rad="rrtmgp">atm/cam/physprops/volc_camRRTMG_byradius_sigma1.6_mode1_c210211.nc</VOLC_MMR1>
+<VOLC_MMR2 rad="rrtmgp">atm/cam/physprops/volc_camRRTMG_byradius_sigma1.6_mode2_c210211.nc</VOLC_MMR2>
+<VOLC_MMR3 rad="rrtmgp">atm/cam/physprops/volc_camRRTMG_byradius_sigma1.2_mode3_c210211.nc</VOLC_MMR3>
+
 <!-- Modal optics calculations -->
 <mam3_mode1_file rad="rrtmg">atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_c141106.nc</mam3_mode1_file>
 <mam3_mode2_file rad="rrtmg">atm/cam/physprops/mam4_mode2_rrtmg_aitkendust_c141106.nc </mam3_mode2_file>
@@ -509,6 +555,36 @@
 <mam7_mode6_file rad="rrtmg">atm/cam/physprops/mam7_mode6_rrtmg_c120904.nc</mam7_mode6_file>
 <mam7_mode7_file rad="rrtmg">atm/cam/physprops/mam7_mode7_rrtmg_c120904.nc</mam7_mode7_file>
 
+<!-- Modal optics for RRTMGP -->
+<mam3_mode1_file rad="rrtmgp">atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_c141106.nc</mam3_mode1_file>
+<mam3_mode2_file rad="rrtmgp">atm/cam/physprops/mam4_mode2_rrtmg_aitkendust_c141106.nc </mam3_mode2_file>
+<mam3_mode3_file rad="rrtmgp">atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_c141106.nc</mam3_mode3_file>
+
+<mam3_mode1_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_sig1.6_dgnh.48_c140304.nc</mam3_mode1_file>
+<mam3_mode3_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_sig1.2_dgnl.40_c150219.nc</mam3_mode3_file>
+
+<mam4_mode1_file rad="rrtmgp">atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_c141106.nc</mam4_mode1_file>
+<mam4_mode2_file rad="rrtmgp">atm/cam/physprops/mam4_mode2_rrtmg_aitkendust_c141106.nc</mam4_mode2_file>
+<mam4_mode3_file rad="rrtmgp">atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_c141106.nc</mam4_mode3_file>
+<mam4_mode4_file rad="rrtmgp">atm/cam/physprops/mam4_mode4_rrtmg_c130628.nc</mam4_mode4_file>
+
+<mam4_mode1_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_sig1.6_dgnh.48_c140304.nc</mam4_mode1_file>
+<mam4_mode3_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_sig1.2_dgnl.40_c150219.nc</mam4_mode3_file>
+
+<mam5_mode1_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode1_rrtmg_aeronetdust_sig1.6_dgnh.48_c140304.nc</mam5_mode1_file>
+<mam5_mode2_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode2_rrtmg_aitkendust_c141106.nc</mam5_mode2_file>
+<mam5_mode3_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_c141106.nc</mam5_mode3_file>
+<mam5_mode4_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode4_rrtmg_c130628.nc</mam5_mode4_file>
+<mam5_mode5_file rad="rrtmgp" ver="strat">atm/cam/physprops/mam4_mode3_rrtmg_aeronetdust_sig1.2_dgnl.40_c150219.nc</mam5_mode5_file>
+
+<mam7_mode1_file rad="rrtmgp">atm/cam/physprops/mam7_mode1_rrtmg_c120904.nc</mam7_mode1_file>
+<mam7_mode2_file rad="rrtmgp">atm/cam/physprops/mam7_mode2_rrtmg_c120904.nc</mam7_mode2_file>
+<mam7_mode3_file rad="rrtmgp">atm/cam/physprops/mam7_mode3_rrtmg_c120904.nc</mam7_mode3_file>
+<mam7_mode4_file rad="rrtmgp">atm/cam/physprops/mam7_mode4_rrtmg_c120904.nc</mam7_mode4_file>
+<mam7_mode5_file rad="rrtmgp">atm/cam/physprops/mam7_mode5_rrtmg_c120904.nc</mam7_mode5_file>
+<mam7_mode6_file rad="rrtmgp">atm/cam/physprops/mam7_mode6_rrtmg_c120904.nc</mam7_mode6_file>
+<mam7_mode7_file rad="rrtmgp">atm/cam/physprops/mam7_mode7_rrtmg_c120904.nc</mam7_mode7_file>
+
 <water_refindex_file>atm/cam/physprops/water_refindex_rrtmg_c080910.nc</water_refindex_file>
 
 <modal_accum_coarse_exch               >.false.</modal_accum_coarse_exch>
@@ -523,6 +599,15 @@
 <iceopticsfile rad="rrtmg">atm/cam/physprops/iceoptics_c080917.nc</iceopticsfile>
 <liqopticsfile rad="rrtmg">atm/cam/physprops/F_nwvl200_mu20_lam50_res64_t298_c080428.nc</liqopticsfile>
 
+<!-- RRTMGP -->
+<liqcldoptics  rad="rrtmgp">gammadist</liqcldoptics>
+<icecldoptics  rad="rrtmgp">mitchell</icecldoptics>
+<iceopticsfile rad="rrtmgp">atm/cam/physprops/iceoptics_c080917.nc</iceopticsfile>
+<liqopticsfile rad="rrtmgp">atm/cam/physprops/F_nwvl200_mu20_lam50_res64_t298_c080428.nc</liqopticsfile>
+
+<rrtmgp_coefs_lw_file>src/physics/rrtmgp/data/rrtmgp-gas-lw-g128.nc</rrtmgp_coefs_lw_file>
+<rrtmgp_coefs_sw_file>src/physics/rrtmgp/data/rrtmgp-gas-sw-g112.nc</rrtmgp_coefs_sw_file>
+
 <!-- CAM-RT absorptivity/emissivity lookup table -->
 <absems_data rad="camrt">atm/cam/rad/abs_ems_factors_fastvx.c030508.nc</absems_data>
 
@@ -1908,7 +1993,7 @@
 <gas_wetdep_method  phys="spcam_m2005"   >OFF</gas_wetdep_method>
 
 <!-- Dry Dep surface data file needed by prognostic MAM on unstructured grid only. -->
-<drydep_srf_file hgrid="ne3np4"  npg="3" >atm/cam/chem/trop_mam/atmsrf_ne3np4.pg3_c221214.nc</drydep_srf_file>
+<drydep_srf_file hgrid="ne3np4"  npg="3" >atm/cam/chem/trop_mam/atmsrf_ne3np4.pg3_221214.nc</drydep_srf_file>
 <drydep_srf_file hgrid="ne5np4"          >atm/cam/chem/trop_mam/atmsrf_ne5np4_110920.nc</drydep_srf_file>
 <drydep_srf_file hgrid="ne5np4"   npg="3">atm/cam/chem/trop_mam/atmsrf_ne5pg3_201105.nc</drydep_srf_file>
 <drydep_srf_file hgrid="ne16np4"         >atm/cam/chem/trop_mam/atmsrf_ne16np4_110920.nc</drydep_srf_file>
diff --git a/bld/namelist_files/namelist_definition.xml b/bld/namelist_files/namelist_definition.xml
index 14da5403a3..9d7c323b59 100644
--- a/bld/namelist_files/namelist_definition.xml
+++ b/bld/namelist_files/namelist_definition.xml
@@ -5467,7 +5467,7 @@ Default: Unused
 
 <!-- Radiation -->
 <entry id="radiation_scheme" type="char*16" category="radiation"
-       group="phys_ctl_nl" valid_values="rrtmg,camrt" >
+       group="phys_ctl_nl" valid_values="rrtmgp,rrtmg,camrt" >
 Type of radiation scheme employed.
 Default: set by build-namelist
 </entry>
@@ -5657,6 +5657,25 @@ Switch to turn on Fixed Dynamical Heating in the offline radiation tool (PORT).
 Default: false
 </entry>
 
+<!-- RRTMGP -->
+
+<entry id="rrtmgp_coefs_lw_file" type="char*256" category="radiation"
+       group="radiation_nl" valid_values="" >
+Relative pathname for LW gas optics coefficients for RRTMGP.  This data is
+part of the RRTMGP source, thus this pathname is relative to the root source
+code directory for the CAM component.
+Default: set by build-namelist.
+</entry>
+
+<entry id="rrtmgp_coefs_sw_file" type="char*256" category="radiation"
+       group="radiation_nl" valid_values="" >
+Relative pathname for SW gas optics coefficients for RRTMGP.  This data is
+part of the RRTMGP source, thus this pathname is relative to the root source
+code directory for the CAM component.
+Default: set by build-namelist.
+</entry>
+
+
 <!-- Aerosol and cloud optics -->
 
 <entry id="water_refindex_file" type="char*256" input_pathname="abs" category="radiation"
diff --git a/bld/namelist_files/use_cases/1850_cam5.xml b/bld/namelist_files/use_cases/1850_cam5.xml
new file mode 100644
index 0000000000..f33151bb3d
--- /dev/null
+++ b/bld/namelist_files/use_cases/1850_cam5.xml
@@ -0,0 +1,54 @@
+<?xml version="1.0"?>
+
+<namelist_defaults>
+
+<!-- Solar constant from Lean (via Caspar Ammann) -->
+<solar_data_file>atm/cam/solar/SOLAR_SPECTRAL_Lean_1610-2008_annual_c090324.nc</solar_data_file>
+<solar_data_ymd>18500101</solar_data_ymd>
+<solar_data_type>FIXED</solar_data_type>
+
+<!-- 1850 GHG values from ipcc-ar4-cfcs-1850-2000.xls (Doug Kinnison) -->
+<co2vmr>284.7e-6</co2vmr>
+<ch4vmr>791.6e-9</ch4vmr>
+<n2ovmr>275.68e-9</n2ovmr>
+<f11vmr>12.48e-12</f11vmr>
+<f12vmr>0.0</f12vmr>
+
+<!-- 1850 ozone data is from Jean-Francois Lamarque -->
+<prescribed_ozone_datapath>atm/cam/ozone</prescribed_ozone_datapath>
+<prescribed_ozone_file>ozone_1.9x2.5_L26_1850clim_c090420.nc</prescribed_ozone_file>
+<prescribed_ozone_name>O3</prescribed_ozone_name>
+<prescribed_ozone_type>CYCLICAL</prescribed_ozone_type>
+<prescribed_ozone_cycle_yr>1850</prescribed_ozone_cycle_yr>
+
+<!-- Surface emissions for MAM -->
+<srf_emis_type>CYCLICAL</srf_emis_type>
+<dms_emis_file	   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/aerocom_mam3_dms_surf_2000_c090129.nc</dms_emis_file>
+<so2_emis_file	   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_so2_surf_1850_c090726.nc</so2_emis_file>
+<soag_emis_file	   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_soag_1.5_surf_1850_c100217.nc</soag_emis_file>
+<bc_a1_emis_file   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_bc_surf_1850_c090726.nc</bc_a1_emis_file>
+<pom_a1_emis_file  chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_oc_surf_1850_c090726.nc</pom_a1_emis_file>
+<so4_a1_emis_file  chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_so4_a1_surf_1850_c090726.nc</so4_a1_emis_file>
+<so4_a2_emis_file  chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_so4_a2_surf_1850_c090726.nc</so4_a2_emis_file>
+<num_a1_emis_file  chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_num_a1_surf_1850_c090726.nc</num_a1_emis_file>
+<num_a2_emis_file  chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_num_a2_surf_1850_c090726.nc</num_a2_emis_file>
+
+<!-- External forcing for BAM or MAM -->
+<ext_frc_type>CYCLICAL</ext_frc_type>
+<so2_ext_file      chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_so2_elev_1850_c090726.nc </so2_ext_file>
+<so4_a1_ext_file   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_so4_a1_elev_1850_c090726.nc</so4_a1_ext_file>
+<so4_a2_ext_file   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_so4_a2_elev_1850_c090726.nc</so4_a2_ext_file>
+<num_a1_ext_file   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_num_a1_elev_1850_c090726.nc</num_a1_ext_file>
+<num_a2_ext_file   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_num_a2_elev_1850_c090726.nc</num_a2_ext_file>
+<pom_a1_ext_file   chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_oc_elev_1850_c090726.nc </pom_a1_ext_file>
+<bc_a1_ext_file    chem="trop_mam3">atm/cam/chem/trop_mozart_aero/emis/ar5_mam3_bc_elev_1850_c090726.nc </bc_a1_ext_file>
+
+<!-- Prescribed oxidants for aerosol chemistry -->
+<tracer_cnst_type>CYCLICAL</tracer_cnst_type>
+<tracer_cnst_cycle_yr>1850</tracer_cnst_cycle_yr>
+<tracer_cnst_file>oxid_1.9x2.5_L26_1850clim_c091123.nc</tracer_cnst_file>
+
+<!-- sim_year used for CLM datasets and SSTs forcings -->
+<sim_year>1850</sim_year>
+
+</namelist_defaults>
diff --git a/cime_config/testdefs/testlist_cam.xml b/cime_config/testdefs/testlist_cam.xml
index 4b6647697d..62cd0af626 100644
--- a/cime_config/testdefs/testlist_cam.xml
+++ b/cime_config/testdefs/testlist_cam.xml
@@ -215,6 +215,15 @@
       <option name="wallclock">00:10:00</option>
     </options>
   </test>
+  <test compset="QPC6" grid="ne3pg3_ne3pg3_mg37" name="ERP_D_Ln9" testmods="cam/outfrq9s_rrtmgp">
+    <machines>
+      <machine name="izumi" compiler="gnu" category="aux_cam"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:10:00</option>
+      <option name="comment" >CAM6 aquaplanet w/ RRTMGP</option>
+    </options>
+  </test>
   <test compset="QPRCEMIP" grid="ne30_ne30_mg17" name="ERP_Ln9_Vnuopc" testmods="cam/outfrq9s">
     <machines>
       <machine name="derecho" compiler="intel" category="prebeta"/>
@@ -1791,6 +1800,15 @@
       <option name="comment">CAM7 dev low top ~40 km</option>
     </options>
   </test>
+  <test compset="FLTHIST" grid="ne30pg3_ne30pg3_mg17" name="ERP_D_Ln9" testmods="cam/outfrq9s_rrtmgp">
+    <machines>
+      <machine name="derecho" compiler="intel" category="aux_cam"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:20:00</option>
+      <option name="comment">CAM7 dev low top ~40 km w/ RRTMGP</option>
+    </options>
+  </test>
   <test compset="FMTHIST" grid="ne30pg3_ne30pg3_mg17" name="SMS_D_Ln9" testmods="cam/outfrq9s">
     <machines>
       <machine name="derecho" compiler="intel" category="aux_cam"/>
@@ -1800,6 +1818,15 @@
       <option name="comment">CAM7 dev mid top ~80 km</option>
     </options>
   </test>
+  <test compset="FMTHIST" grid="ne30pg3_ne30pg3_mg17" name="SMS_D_Ln9" testmods="cam/outfrq9s_rrtmgp">
+    <machines>
+      <machine name="derecho" compiler="intel" category="prealpha"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:20:00</option>
+      <option name="comment">CAM7 dev mid top ~80 km w/ RRTMGP</option>
+    </options>
+  </test>
   <test compset="FMTHIST" grid="ne30pg3_ne30pg3_mg17" name="ERP_D_Ln9" testmods="cam/outfrq9s">
     <machines>
       <machine name="derecho" compiler="intel" category="prealpha"/>
@@ -2753,6 +2780,15 @@
       <option name="wallclock">00:40:00</option>
     </options>
   </test>
+  <test compset="FW2000climo" grid="ne30pg3_ne30pg3_mg17" name="SMS_Ln9" testmods="cam/outfrq9s_rrtmgp">
+    <machines>
+      <machine name="derecho" compiler="intel" category="aux_cam"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:10:00</option>
+      <option name="comment">WACCM w/ RRTMGP</option>
+    </options>
+  </test>
   <test compset="FW2000climo" grid="ne30pg3_ne30pg3_mg17" name="SMS_D_Ln9_Vnuopc" testmods="cam/outfrq9s">
     <machines>
       <machine name="derecho" compiler="intel" category="waccm"/>
@@ -2841,6 +2877,15 @@
       <option name="wallclock">00:30:00</option>
     </options>
   </test>
+  <test compset="PC6" grid="f09_f09_mg17" name="SMS_Ld5" testmods="cam/cam6_port_f09_rrtmgp">
+    <machines>
+      <machine name="izumi" compiler="gnu" category="aux_cam"/>
+    </machines>
+    <options>
+      <option name="wallclock">00:30:00</option>
+      <option name="comment">CAM6 PORT w/ RRTMGP</option>
+    </options>
+  </test>
 
   <test compset="FHS94" grid="ne5_ne5_mg37" name="ERP_Ln9_Vnuopc" testmods="cam/outfrq9s">
     <machines>
diff --git a/cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/shell_commands b/cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/shell_commands
new file mode 100644
index 0000000000..106897a2c6
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/shell_commands
@@ -0,0 +1,3 @@
+./xmlchange --append CAM_CONFIG_OPTS="-rad rrtmgp"
+./xmlchange ROF_NCPL=\$ATM_NCPL
+./xmlchange GLC_NCPL=\$ATM_NCPL
diff --git a/cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/user_nl_cam b/cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/user_nl_cam
new file mode 100644
index 0000000000..fcbd0d438b
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/user_nl_cam
@@ -0,0 +1,15 @@
+ offline_driver_infile = '$DIN_LOC_ROOT/atm/cam/port/base_cam6_3mode_1deg.doubleCO2.cam.h1.0001-01-01-00000_c170526.nc'
+ rad_data_fdh = .true.
+ empty_htapes = .true.
+ avgflag_pertape = 'A','I'
+ fincl1 = 'SOLIN', 'QRS', 'FSNS', 'FSNT','FSNSC', 'FSDSC','FSNR','FLNR',
+          'FSNTOA', 'FSUTOA', 'FSNTOAC', 'FSNTC', 'FSDSC', 'FSDS', 'SWCF',
+          'QRL', 'FLNS', 'FLDS', 'FLNT', 'LWCF', 'FLUT' ,'FLUTC', 'FLNTC',
+          'FLNSC', 'FLDSC'
+ fincl2 = 'SOLIN', 'QRS', 'FSNS', 'FSNT','FSNSC', 'FSDSC','FSNR','FLNR',
+          'FSNTOA', 'FSUTOA', 'FSNTOAC', 'FSNTC', 'FSDSC', 'FSDS', 'SWCF',
+          'QRL', 'FLNS', 'FLDS', 'FLNT', 'LWCF', 'FLUT' ,'FLUTC', 'FLNTC',
+          'FLNSC', 'FLDSC'
+ rad_data_output = .false.
+ mfilt=100,100
+ nhtfrq=-120,73
diff --git a/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/shell_commands b/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/shell_commands
new file mode 100644
index 0000000000..106897a2c6
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/shell_commands
@@ -0,0 +1,3 @@
+./xmlchange --append CAM_CONFIG_OPTS="-rad rrtmgp"
+./xmlchange ROF_NCPL=\$ATM_NCPL
+./xmlchange GLC_NCPL=\$ATM_NCPL
diff --git a/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_cam b/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_cam
new file mode 100644
index 0000000000..8482082dce
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_cam
@@ -0,0 +1,4 @@
+mfilt=1,1,1,1,1,1
+ndens=1,1,1,1,1,1
+nhtfrq=9,9,9,9,9,9
+inithist='ENDOFRUN'
diff --git a/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_clm b/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_clm
new file mode 100644
index 0000000000..0d83b5367b
--- /dev/null
+++ b/cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_clm
@@ -0,0 +1,27 @@
+!----------------------------------------------------------------------------------
+! Users should add all user specific namelist changes below in the form of 
+! namelist_var = new_namelist_value 
+!
+! Include namelist variables for drv_flds_in ONLY if -megan and/or -drydep options
+! are set in the CLM_NAMELIST_OPTS env variable.
+!
+! EXCEPTIONS: 
+! Set use_cndv           by the compset you use and the CLM_BLDNML_OPTS -dynamic_vegetation setting
+! Set use_vichydro       by the compset you use and the CLM_BLDNML_OPTS -vichydro           setting
+! Set use_cn             by the compset you use and CLM_BLDNML_OPTS -bgc  setting
+! Set use_crop           by the compset you use and CLM_BLDNML_OPTS -crop setting
+! Set spinup_state       by the CLM_BLDNML_OPTS -bgc_spinup      setting
+! Set irrigate           by the CLM_BLDNML_OPTS -irrig           setting
+! Set dtime              with L_NCPL                             option
+! Set fatmlndfrc         with LND_DOMAIN_PATH/LND_DOMAIN_FILE    options
+! Set finidat            with RUN_REFCASE/RUN_REFDATE/RUN_REFTOD options for hybrid or branch cases
+!                        (includes $inst_string for multi-ensemble cases)
+! Set glc_grid           with CISM_GRID                          option
+! Set glc_smb            with GLC_SMB                            option
+! Set maxpatch_glcmec    with GLC_NEC                            option
+! Set glc_do_dynglacier  with GLC_TWO_WAY_COUPLING               env variable
+!----------------------------------------------------------------------------------
+hist_nhtfrq = 9
+hist_mfilt  = 1
+hist_ndens  = 1
+
diff --git a/doc/ChangeLog b/doc/ChangeLog
index 9d40f7ba63..5ea328d2c8 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,5 +1,208 @@
 ===============================================================
 
+Tag name: cam6_3_148
+Originator(s): brianpm, courtneyp, eaton
+Date: Wed 21 Feb 2024
+One-line Summary:  Provide RRTMGP as a radiation parameterization
+Github PR URL: https://github.com/ESCOMP/CAM/pull/909
+
+Purpose of changes (include the issue number and title text for each relevant GitHub issue):
+
+#255 - Provide RRTMGP as a radiation parameterization
+https://github.com/ESCOMP/CAM/issues/255
+
+Miscellaneous:
+. The 1850_cam5.xml use case file was added back to the source code to
+  facilitate running the F1850 compset with CAM5.  That discussion is in
+  issue #393.
+
+Describe any changes made to build system:
+. '-rad' argument to configure accepts the values 'rrtmgp' and 'rrtmgp_gpu'
+  to build the RRTMGP code for CPUs or for GPUs.
+
+Describe any changes made to the namelist:
+. add variables rrtmgp_coefs_lw_file and rrtmgp_coefs_sw_file to contain
+  filepaths for the RRTMGP coefficients files.
+
+List any changes to the defaults for the boundary datasets: none
+
+Describe any substantial timing or memory changes:
+. performance evaluation of RRTMGP has not yet been done.
+
+Code reviewed by: nusbaume, cacraigucar, sjsprecious
+
+List all files eliminated:
+
+src/physics/rrtmg/cloud_rad_props.F90
+src/physics/rrtmg/ebert_curry.F90
+src/physics/rrtmg/oldcloud.F90
+src/physics/rrtmg/slingo.F90
+. these cloud optics files which can be shared by rrtmg and rrtmgp are
+  moved to src/physics/cam 
+
+List all files added and what they do:
+
+bld/namelist_files/use_cases/1850_cam5.xml
+. use case file for 1850 cam5 physics
+
+cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/shell_commands
+cime_config/testdefs/testmods_dirs/cam/cam6_port_f09_rrtmgp/user_nl_cam
+cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/shell_commands
+cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_cam
+cime_config/testdefs/testmods_dirs/cam/outfrq9s_rrtmgp/user_nl_clm
+. for adding RRTMGP to tests
+
+src/physics/cam/cloud_rad_props.F90
+src/physics/cam/ebert_curry_ice_optics.F90
+src/physics/cam/oldcloud_optics.F90
+src/physics/cam/slingo_liq_optics.F90
+. these 4 files are shared cloud optics code moved here from
+  src/physics/rrtmg/ with the following name changes:
+  - ebert_curry.F90 -> ebert_curry_ice_optics.F90
+  - oldcloud.F90    -> oldcloud_optics.F90
+  - slingo.F90      -> slingo_liq_optics.F90
+. remove unused code, cleanup unused vars, improve endrun messages
+. module names changed to match file names.
+
+src/physics/rrtmgp/mcica_subcol_gen.F90
+src/physics/rrtmgp/radconstants.F90
+src/physics/rrtmgp/radiation.F90
+src/physics/rrtmgp/rrtmgp_inputs.F90
+. CAM interface code for RRTMGP.
+
+List all existing files that have been modified, and describe the changes:
+
+.gitignore
+. add directories src/physics/rrtmgp/{data,ext}
+
+Externals_CAM.cfg
+. add external definition for rte-rrtmgp source
+. add external definition for rrtmgp data
+
+bld/build-namelist
+. set the correct filepaths for the coefficient datasets which are checked
+  out in the source code directory tree.
+. generalize logic to include both rrtmgp and rrtmg when appropriate
+. add error check for old cloud optics no longer supported
+
+bld/config_files/definition.xml
+. add 'rrtmgp' as valid value for 'rad' configure option
+
+bld/configure
+. add rrtmgp and rrtmgp_gpu as valid values for '-rad' argument.
+. '-rad rrtmgp_gpu' sets a flag used to add the filepaths for the GPU code
+  versions to the Filepath file.  The '_gpu' suffix is removed before
+  setting the parameter value for 'rad' in the config_cache.xml file.
+. check to disallow CARMA + RRTMGP
+
+bld/namelist_files/namelist_defaults_cam.xml
+. the aersol and cloud optics datasets for RRTMG are being reused for
+  RRTMGP for now
+
+bld/namelist_files/namelist_definition.xml
+. add 'rrtmgp' as valid value for 'radiation_scheme'
+. add variables rrtmgp_coefs_lw_file and rrtmgp_coefs_sw_file to contain
+  filepaths for the RRTMGP coefficients files.
+
+cime_config/testdefs/testlist_cam.xml
+. add aux_cam tests:
+  ERP_D_Ln9.ne30pg3_ne30pg3_mg17.FLTHIST.derecho_intel.cam-outfrq9s_rrtmgp
+  SMS_Ln9.ne30pg3_ne30pg3_mg17.FW2000climo.derecho_intel.cam-outfrq9s_rrtmgp
+  ERP_D_Ln9.ne5pg3_ne5pg3_mg37.QPC6.izumi_nag.cam-outfrq9s_rrtmgp
+  SMS_Ld5.f09_f09_mg17.PC6.izumi_gnu.cam-cam6_port_f09_rrtmgp
+. add prealpha test:
+  SMS_D_Ln9.ne30pg3_ne30pg3_mg17.FMTHIST.derecho_intel.cam-outfrq9s_rrtmgp
+
+src/chemistry/utils/solar_data.F90
+. add solar_htng_spctrl_scl to log file output
+
+src/physics/cam/aer_rad_props.F90
+. nrh, ot_length now accessed from phys_prop
+
+src/physics/cam/aerosol_optics_cam.F90
+. ot_length now accessed from phys_prop
+
+src/physics/cam/phys_prop.F90
+. add the public parameter nrh to this module.  Was previously in
+  radconstants. 
+. turn off old debug output to log file
+
+src/physics/cam/physpkg.F90
+. reorder initialization of solar_data and radiation modules to allow
+  reading the spectral band boundaries from the input data rather than
+  requiring them to be hardcoded.
+
+src/physics/cam/rad_constituents.F90
+. access ot_length from phys_prop rather than rad_constituents
+
+src/physics/cam_dev/physpkg.F90
+. reorder initialization of solar_data and radiation modules to allow
+  reading the wavenumber band boundaries from the input data rather than
+  requiring them to be hardcoded.
+
+src/physics/camrt/radconstants.F90
+. parameters ot_length and nrh moved to phys_props
+
+src/physics/rrtmg/radconstants.F90
+. parameters ot_length and nrh moved to phys_props
+
+src/physics/rrtmg/radiation.F90
+. ebert_curry -> ebert_curry_ice_optics
+
+src/physics/simple/radconstants.F90
+. parameters ot_length and nrh moved to phys_props
+. add dummy interface for get_sw_spectral_boundaries
+
+src/physics/spcam/crm/CLUBB/crmx_mt95.f90
+. removed 3 non-ascii characters (in comments)
+
+test/system/TR8.sh
+. add checks for rrtmgp interface code
+
+If there were any failures reported from running test_driver.sh on any test
+platform, and checkin with these failures has been OK'd by the gatekeeper,
+then copy the lines from the td.*.status files for the failed tests to the
+appropriate machine below.  All failed tests must be justified.
+
+derecho/intel/aux_cam:
+
+  ERP_Ln9_Vnuopc.C96_C96_mg17.F2000climo.derecho_intel.cam-outfrq9s_mg3 (Overall: PEND) details:
+  ERP_Ln9_Vnuopc.f09_f09_mg17.FCSD_HCO.derecho_intel.cam-outfrq9s (Overall: FAIL) details:
+  SMS_Ld1_Vnuopc.f09_f09_mg17.FCHIST_GC.derecho_intel.cam-outfrq1d (Overall: PEND) details:
+-- pre-existing failures
+
+  ERP_D_Ln9.ne30pg3_ne30pg3_mg17.FLTHIST.derecho_intel.cam-outfrq9s_rrtmgp (Overall: DIFF) details:
+    FAIL ERP_D_Ln9.ne30pg3_ne30pg3_mg17.FLTHIST.derecho_intel.cam-outfrq9s_rrtmgp NLCOMP
+    FAIL ERP_D_Ln9.ne30pg3_ne30pg3_mg17.FLTHIST.derecho_intel.cam-outfrq9s_rrtmgp BASELINE /glade/campaign/cesm/community/amwg/cam_baselines/cam6_3_147: ERROR BFAIL baseline directory '/glade/campaign/cesm/community/amwg/cam_baselines/cam6_3_147/ERP_D_Ln9.ne30pg3_ne30pg3_mg17.FLTHIST.derecho_intel.cam-outfrq9s_rrtmgp' does not exist
+  SMS_Ln9.ne30pg3_ne30pg3_mg17.FW2000climo.derecho_intel.cam-outfrq9s_rrtmgp (Overall: DIFF) details:
+    FAIL SMS_Ln9.ne30pg3_ne30pg3_mg17.FW2000climo.derecho_intel.cam-outfrq9s_rrtmgp NLCOMP
+    FAIL SMS_Ln9.ne30pg3_ne30pg3_mg17.FW2000climo.derecho_intel.cam-outfrq9s_rrtmgp BASELINE /glade/campaign/cesm/community/amwg/cam_baselines/cam6_3_147: ERROR BFAIL baseline directory '/glade/campaign/cesm/community/amwg/cam_baselines/cam6_3_147/SMS_Ln9.ne30pg3_ne30pg3_mg17.FW2000climo.derecho_intel.cam-outfrq9s_rrtmgp' does not exist
+-- expected diffs - no baselines for new tests
+
+izumi/nag/aux_cam:
+
+  DAE_Vnuopc.f45_f45_mg37.FHS94.izumi_nag.cam-dae (Overall: FAIL) details:
+-- pre-existing failure
+
+izumi/gnu/aux_cam:
+
+  ERP_D_Ln9.ne3pg3_ne3pg3_mg37.QPC6.izumi_gnu.cam-outfrq9s_rrtmgp (Overall: DIFF) details:
+    FAIL ERP_D_Ln9.ne3pg3_ne3pg3_mg37.QPC6.izumi_gnu.cam-outfrq9s_rrtmgp NLCOMP
+    FAIL ERP_D_Ln9.ne3pg3_ne3pg3_mg37.QPC6.izumi_gnu.cam-outfrq9s_rrtmgp BASELINE /fs/cgd/csm/models/atm/cam/pretag_bl/cam6_3_147_gnu: ERROR BFAIL baseline directory '/fs/cgd/csm/models/atm/cam/pretag_bl/cam6_3_147_gnu/ERP_D_Ln9.ne3pg3_ne3pg3_mg37.QPC6.izumi_gnu.cam-outfrq9s_rrtmgp' does not exist
+  SMS_Ld5.f09_f09_mg17.PC6.izumi_gnu.cam-cam6_port_f09_rrtmgp (Overall: DIFF) details:
+    FAIL SMS_Ld5.f09_f09_mg17.PC6.izumi_gnu.cam-cam6_port_f09_rrtmgp NLCOMP
+    FAIL SMS_Ld5.f09_f09_mg17.PC6.izumi_gnu.cam-cam6_port_f09_rrtmgp BASELINE /fs/cgd/csm/models/atm/cam/pretag_bl/cam6_3_147_gnu: ERROR BFAIL baseline directory '/fs/cgd/csm/models/atm/cam/pretag_bl/cam6_3_147_gnu/SMS_Ld5.f09_f09_mg17.PC6.izumi_gnu.cam-cam6_port_f09_rrtmgp' does not exist
+-- expected diffs - no baselines for new tests
+
+CAM tag used for the baseline comparison tests if different than previous
+tag:
+
+Summarize any changes to answers: None.
+  New RRTMGP option changes answers only when enabled.
+
+===============================================================
+===============================================================
+
 Tag name: cam6_3_147
 Originator(s): lizziel, jimmielin, fritzt
 Date: 2 Feb 2024
diff --git a/src/chemistry/utils/solar_data.F90 b/src/chemistry/utils/solar_data.F90
index da18fbc777..51ad7ad82b 100644
--- a/src/chemistry/utils/solar_data.F90
+++ b/src/chemistry/utils/solar_data.F90
@@ -91,6 +91,7 @@ subroutine solar_data_readnl( nlfile )
        write(iulog,*) 'solar_data_readnl: solar_data_type = ',trim(solar_data_type)
        write(iulog,*) 'solar_data_readnl: solar_data_ymd  = ',solar_data_ymd
        write(iulog,*) 'solar_data_readnl: solar_data_tod  = ',solar_data_tod
+       write(iulog,*) 'solar_data_readnl: solar_htng_spctrl_scl  = ',solar_htng_spctrl_scl
     endif
 
     solar_parms_on = solar_parms_data_file.ne.'NONE'
diff --git a/src/physics/cam/aer_rad_props.F90 b/src/physics/cam/aer_rad_props.F90
index 3d46fe9ba8..08dced5a93 100644
--- a/src/physics/cam/aer_rad_props.F90
+++ b/src/physics/cam/aer_rad_props.F90
@@ -11,7 +11,8 @@ module aer_rad_props
 use physics_types,    only: physics_state
 
 use physics_buffer,   only: physics_buffer_desc
-use radconstants,     only: nrh, nswbands, nlwbands, idx_sw_diag, ot_length
+use radconstants,     only: nswbands, nlwbands, idx_sw_diag
+use phys_prop,        only: nrh, ot_length
 use rad_constituents, only: rad_cnst_get_info, rad_cnst_get_aer_mmr, &
                             rad_cnst_get_aer_props
 use wv_saturation,    only: qsat
@@ -129,7 +130,7 @@ subroutine aer_rad_props_sw(list_idx, state, pbuf,  nnite, idxnite, &
 
    real(r8), intent(out) :: tau    (pcols,0:pver,nswbands) ! aerosol extinction optical depth
    real(r8), intent(out) :: tau_w  (pcols,0:pver,nswbands) ! aerosol single scattering albedo * tau
-   real(r8), intent(out) :: tau_w_g(pcols,0:pver,nswbands) ! aerosol assymetry parameter * tau * w
+   real(r8), intent(out) :: tau_w_g(pcols,0:pver,nswbands) ! aerosol asymmetry parameter * tau * w
    real(r8), intent(out) :: tau_w_f(pcols,0:pver,nswbands) ! aerosol forward scattered fraction * tau * w
 
    ! Local variables
@@ -308,9 +309,6 @@ end subroutine aer_rad_props_sw
 
 subroutine aer_rad_props_lw(list_idx, state, pbuf,  odap_aer)
 
-   use radconstants,  only: ot_length
-
-   use physics_buffer, only : pbuf_get_field, pbuf_get_index, physics_buffer_desc
    ! Purpose: Compute aerosol transmissions needed in absorptivity/
    !    emissivity calculations
 
@@ -318,6 +316,8 @@ subroutine aer_rad_props_lw(list_idx, state, pbuf,  odap_aer)
    ! species.  If this changes, this routine will need to do something
    ! similar to the sw with routines like get_hygro_lw_abs
 
+   use physics_buffer, only : pbuf_get_field, pbuf_get_index, physics_buffer_desc
+
    ! Arguments
    integer,             intent(in)  :: list_idx                      ! index of the climate or a diagnostic list
    type(physics_state), intent(in), target :: state
diff --git a/src/physics/cam/aerosol_optics_cam.F90 b/src/physics/cam/aerosol_optics_cam.F90
index eb094446c8..a81e1d4701 100644
--- a/src/physics/cam/aerosol_optics_cam.F90
+++ b/src/physics/cam/aerosol_optics_cam.F90
@@ -3,7 +3,8 @@ module aerosol_optics_cam
   use shr_kind_mod, only: cl => shr_kind_cl
   use cam_logfile,  only: iulog
   use radconstants, only: nswbands, nlwbands, idx_sw_diag, idx_uv_diag, idx_nir_diag
-  use radconstants, only: ot_length, get_lw_spectral_boundaries
+  use radconstants, only: get_lw_spectral_boundaries
+  use phys_prop,    only: ot_length
   use physics_types,only: physics_state
   use physics_buffer,only: physics_buffer_desc
   use ppgrid, only: pcols, pver
diff --git a/src/physics/rrtmg/cloud_rad_props.F90 b/src/physics/cam/cloud_rad_props.F90
similarity index 64%
rename from src/physics/rrtmg/cloud_rad_props.F90
rename to src/physics/cam/cloud_rad_props.F90
index 2911e0ac21..257138e7b5 100644
--- a/src/physics/rrtmg/cloud_rad_props.F90
+++ b/src/physics/cam/cloud_rad_props.F90
@@ -7,16 +7,21 @@ module cloud_rad_props
 use ppgrid,           only: pcols, pver, pverp
 use physics_types,    only: physics_state
 use physics_buffer,   only: physics_buffer_desc, pbuf_get_index, pbuf_get_field, pbuf_old_tim_idx
-use radconstants,     only: nswbands, nlwbands, idx_sw_diag, ot_length, idx_lw_diag
-use cam_abortutils,   only: endrun
+use constituents,     only: cnst_get_ind
+use radconstants,     only: nswbands, nlwbands, idx_sw_diag
 use rad_constituents, only: iceopticsfile, liqopticsfile
-use oldcloud,         only: oldcloud_lw, old_liq_get_rad_props_lw, old_ice_get_rad_props_lw, oldcloud_init
+use oldcloud_optics,  only: oldcloud_init, oldcloud_lw, &
+                            old_liq_get_rad_props_lw, old_ice_get_rad_props_lw
+                            
+use slingo_liq_optics,      only: slingo_rad_props_init
+use ebert_curry_ice_optics, only: ec_rad_props_init, scalefactor
+
+use interpolate_data, only: interp_type, lininterp_init, lininterp, &
+                            extrap_method_bndry, lininterp_finish
 
-use ebert_curry,      only: scalefactor
 use cam_logfile,      only: iulog
+use cam_abortutils,   only: endrun
 
-use interpolate_data, only: interp_type, lininterp_init, lininterp, &
-     extrap_method_bndry, lininterp_finish
 
 implicit none
 private
@@ -24,16 +29,15 @@ module cloud_rad_props
 
 public :: &
    cloud_rad_props_init,          &
-   cloud_rad_props_get_sw,        & ! return SW optical props of total bulk aerosols
-   cloud_rad_props_get_lw,        & ! return LW optical props of total bulk aerosols
+   cloud_rad_props_get_lw,        & ! return LW optical props for old cloud optics
    get_ice_optics_sw,             & ! return Mitchell SW ice radiative properties
-   ice_cloud_get_rad_props_lw,    & ! Mitchell LW ice rad props
-   get_liquid_optics_sw,          & ! return Conley SW rad props
-   liquid_cloud_get_rad_props_lw, & ! return Conley LW rad props
-   grau_cloud_get_rad_props_lw,   &
-   get_grau_optics_sw, &
+   ice_cloud_get_rad_props_lw,    & ! return Mitchell LW ice radiative properties
+   get_liquid_optics_sw,          & ! return Conley SW radiative properties
+   liquid_cloud_get_rad_props_lw, & ! return Conley LW radiative properties
+   get_snow_optics_sw,            &
    snow_cloud_get_rad_props_lw,   &
-   get_snow_optics_sw
+   get_grau_optics_sw,            &
+   grau_cloud_get_rad_props_lw
 
 
 integer :: nmu, nlambda
@@ -51,24 +55,23 @@ module cloud_rad_props
 real(r8), allocatable :: asm_sw_ice(:,:)
 real(r8), allocatable :: abs_lw_ice(:,:)
 
-!
 ! indexes into pbuf for optical parameters of MG clouds
-!
-   integer :: i_dei=0
-   integer :: i_mu=0
-   integer :: i_lambda=0
-   integer :: i_iciwp=0
-   integer :: i_iclwp=0
-   integer :: i_des=0
-   integer :: i_icswp=0
-   integer :: i_degrau=0
-   integer :: i_icgrauwp=0
+integer :: i_dei=0
+integer :: i_mu=0
+integer :: i_lambda=0
+integer :: i_iciwp=0
+integer :: i_iclwp=0
+integer :: i_des=0
+integer :: i_icswp=0
+integer :: i_degrau=0
+integer :: i_icgrauwp=0
 
 ! indexes into constituents for old optics
-   integer :: &
-        ixcldice,           & ! cloud ice water index
-        ixcldliq              ! cloud liquid water index
+integer :: &
+   ixcldice,           & ! cloud ice water index
+   ixcldliq              ! cloud liquid water index
 
+real(r8), parameter :: tiny = 1.e-80_r8
 
 !==============================================================================
 contains
@@ -83,9 +86,6 @@ subroutine cloud_rad_props_init()
 #if ( defined SPMD )
    use mpishorthand
 #endif
-   use constituents,   only: cnst_get_ind
-   use slingo,         only: slingo_rad_props_init
-   use ebert_curry,    only: ec_rad_props_init, scalefactor
 
    character(len=256) :: liquidfile
    character(len=256) :: icefile
@@ -102,6 +102,7 @@ subroutine cloud_rad_props_init()
    integer :: d_id, ext_sw_ice_id, ssa_sw_ice_id, asm_sw_ice_id, abs_lw_ice_id
 
    integer :: err
+   character(len=*), parameter :: sub = 'cloud_rad_props_init'
 
    liquidfile = liqopticsfile
    icefile = iceopticsfile
@@ -125,25 +126,25 @@ subroutine cloud_rad_props_init()
    call cnst_get_ind('CLDLIQ', ixcldliq)
 
    ! read liquid cloud optics
-   if(masterproc) then
-   call getfil( trim(liquidfile), locfn, 0)
-   call handle_ncerr( nf90_open(locfn, NF90_NOWRITE, ncid), 'liquid optics file missing')
-   write(iulog,*)' reading liquid cloud optics from file ',locfn
+   if (masterproc) then
+      call getfil( trim(liquidfile), locfn, 0)
+      call handle_ncerr( nf90_open(locfn, NF90_NOWRITE, ncid), 'liquid optics file missing')
+      write(iulog,*)' reading liquid cloud optics from file ',locfn
 
-   call handle_ncerr(nf90_inq_dimid( ncid, 'lw_band', dimid), 'getting lw_band dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nlwbands), 'getting n lw bands')
-   if (f_nlwbands /= nlwbands) call endrun('number of lw bands does not match')
+      call handle_ncerr(nf90_inq_dimid( ncid, 'lw_band', dimid), 'getting lw_band dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nlwbands), 'getting n lw bands')
+      if (f_nlwbands /= nlwbands) call endrun(sub//': number of lw bands does not match')
 
-   call handle_ncerr(nf90_inq_dimid( ncid, 'sw_band', dimid), 'getting sw_band_dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nswbands), 'getting n sw bands')
-   if (f_nswbands /= nswbands) call endrun('number of sw bands does not match')
+      call handle_ncerr(nf90_inq_dimid( ncid, 'sw_band', dimid), 'getting sw_band_dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nswbands), 'getting n sw bands')
+      if (f_nswbands /= nswbands) call endrun(sub//': number of sw bands does not match')
 
-   call handle_ncerr(nf90_inq_dimid( ncid, 'mu', mudimid), 'getting mu dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, mudimid, len=nmu), 'getting n mu samples')
+      call handle_ncerr(nf90_inq_dimid( ncid, 'mu', mudimid), 'getting mu dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, mudimid, len=nmu), 'getting n mu samples')
 
-   call handle_ncerr(nf90_inq_dimid( ncid, 'lambda_scale', lambdadimid), 'getting lambda dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, lambdadimid, len=nlambda), 'getting n lambda samples')
-   endif ! if (masterproc)
+      call handle_ncerr(nf90_inq_dimid( ncid, 'lambda_scale', lambdadimid), 'getting lambda dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, lambdadimid, len=nlambda), 'getting n lambda samples')
+   end if ! if (masterproc)
 
 #if ( defined SPMD )
    call mpibcast(nmu, 1, mpiint, 0, mpicom, ierr)
@@ -157,39 +158,39 @@ subroutine cloud_rad_props_init()
    allocate(asm_sw_liq(nmu,nlambda,nswbands))
    allocate(abs_lw_liq(nmu,nlambda,nlwbands))
 
-   if(masterproc) then
-   call handle_ncerr( nf90_inq_varid(ncid, 'mu', mu_id),&
-      'cloud optics mu get')
-   call handle_ncerr( nf90_get_var(ncid, mu_id, g_mu),&
-      'read cloud optics mu values')
+   if (masterproc) then
+      call handle_ncerr( nf90_inq_varid(ncid, 'mu', mu_id),&
+         'cloud optics mu get')
+      call handle_ncerr( nf90_get_var(ncid, mu_id, g_mu),&
+         'read cloud optics mu values')
 
-   call handle_ncerr( nf90_inq_varid(ncid, 'lambda', lambda_id),&
-      'cloud optics lambda get')
-   call handle_ncerr( nf90_get_var(ncid, lambda_id, g_lambda),&
-      'read cloud optics lambda values')
+      call handle_ncerr( nf90_inq_varid(ncid, 'lambda', lambda_id),&
+         'cloud optics lambda get')
+      call handle_ncerr( nf90_get_var(ncid, lambda_id, g_lambda),&
+         'read cloud optics lambda values')
 
-   call handle_ncerr( nf90_inq_varid(ncid, 'k_ext_sw', ext_sw_liq_id),&
-      'cloud optics ext_sw_liq get')
-   call handle_ncerr( nf90_get_var(ncid, ext_sw_liq_id, ext_sw_liq),&
-      'read cloud optics ext_sw_liq values')
+      call handle_ncerr( nf90_inq_varid(ncid, 'k_ext_sw', ext_sw_liq_id),&
+         'cloud optics ext_sw_liq get')
+      call handle_ncerr( nf90_get_var(ncid, ext_sw_liq_id, ext_sw_liq),&
+         'read cloud optics ext_sw_liq values')
 
-   call handle_ncerr( nf90_inq_varid(ncid, 'ssa_sw', ssa_sw_liq_id),&
-      'cloud optics ssa_sw_liq get')
-   call handle_ncerr( nf90_get_var(ncid, ssa_sw_liq_id, ssa_sw_liq),&
-      'read cloud optics ssa_sw_liq values')
+      call handle_ncerr( nf90_inq_varid(ncid, 'ssa_sw', ssa_sw_liq_id),&
+         'cloud optics ssa_sw_liq get')
+      call handle_ncerr( nf90_get_var(ncid, ssa_sw_liq_id, ssa_sw_liq),&
+         'read cloud optics ssa_sw_liq values')
 
-   call handle_ncerr( nf90_inq_varid(ncid, 'asm_sw', asm_sw_liq_id),&
-      'cloud optics asm_sw_liq get')
-   call handle_ncerr( nf90_get_var(ncid, asm_sw_liq_id, asm_sw_liq),&
-      'read cloud optics asm_sw_liq values')
+      call handle_ncerr( nf90_inq_varid(ncid, 'asm_sw', asm_sw_liq_id),&
+         'cloud optics asm_sw_liq get')
+      call handle_ncerr( nf90_get_var(ncid, asm_sw_liq_id, asm_sw_liq),&
+         'read cloud optics asm_sw_liq values')
 
-   call handle_ncerr( nf90_inq_varid(ncid, 'k_abs_lw', abs_lw_liq_id),&
-      'cloud optics abs_lw_liq get')
-   call handle_ncerr( nf90_get_var(ncid, abs_lw_liq_id, abs_lw_liq),&
-      'read cloud optics abs_lw_liq values')
+      call handle_ncerr( nf90_inq_varid(ncid, 'k_abs_lw', abs_lw_liq_id),&
+         'cloud optics abs_lw_liq get')
+      call handle_ncerr( nf90_get_var(ncid, abs_lw_liq_id, abs_lw_liq),&
+         'read cloud optics abs_lw_liq values')
 
-   call handle_ncerr( nf90_close(ncid), 'liquid optics file missing')
-   endif ! if masterproc
+      call handle_ncerr( nf90_close(ncid), 'liquid optics file missing')
+   end if ! if masterproc
 
 #if ( defined SPMD )
     call mpibcast(g_mu, nmu, mpir8, 0, mpicom, ierr)
@@ -199,28 +200,28 @@ subroutine cloud_rad_props_init()
     call mpibcast(asm_sw_liq, nmu*nlambda*nswbands, mpir8, 0, mpicom, ierr)
     call mpibcast(abs_lw_liq, nmu*nlambda*nlwbands, mpir8, 0, mpicom, ierr)
 #endif
-   ! I forgot to convert kext from m^2/Volume to m^2/Kg
+   ! Convert kext from m^2/Volume to m^2/Kg
    ext_sw_liq = ext_sw_liq / 0.9970449e3_r8
    abs_lw_liq = abs_lw_liq / 0.9970449e3_r8
 
    ! read ice cloud optics
-   if(masterproc) then
-   call getfil( trim(icefile), locfn, 0)
-   call handle_ncerr( nf90_open(locfn, NF90_NOWRITE, ncid), 'ice optics file missing')
-   write(iulog,*)' reading ice cloud optics from file ',locfn
-
-   call handle_ncerr(nf90_inq_dimid( ncid, 'lw_band', dimid), 'getting lw_band dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nlwbands), 'getting n lw bands')
-   if (f_nlwbands /= nlwbands) call endrun('number of lw bands does not match')
-
-   call handle_ncerr(nf90_inq_dimid( ncid, 'sw_band', dimid), 'getting sw_band_dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nswbands), 'getting n sw bands')
-   if (f_nswbands /= nswbands) call endrun('number of sw bands does not match')
-
-   call handle_ncerr(nf90_inq_dimid( ncid, 'd_eff', d_dimid), 'getting deff dim')
-   call handle_ncerr(nf90_inquire_dimension( ncid, d_dimid, len=n_g_d), 'getting n deff samples')
-
-   endif ! if (masterproc)
+   if (masterproc) then
+      call getfil( trim(icefile), locfn, 0)
+      call handle_ncerr( nf90_open(locfn, NF90_NOWRITE, ncid), 'ice optics file missing')
+      write(iulog,*)' reading ice cloud optics from file ',locfn
+      call handle_ncerr(nf90_inq_dimid( ncid, 'lw_band', dimid), 'getting lw_band dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nlwbands), 'getting n lw bands')
+      if (f_nlwbands /= nlwbands) then
+         call endrun(sub//': number of lw bands does not match')
+      end if
+      call handle_ncerr(nf90_inq_dimid( ncid, 'sw_band', dimid), 'getting sw_band_dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, dimid, len=f_nswbands), 'getting n sw bands')
+      if (f_nswbands /= nswbands) then
+         call endrun(sub//': number of sw bands does not match')
+      end if
+      call handle_ncerr(nf90_inq_dimid( ncid, 'd_eff', d_dimid), 'getting deff dim')
+      call handle_ncerr(nf90_inquire_dimension( ncid, d_dimid, len=n_g_d), 'getting n deff samples')
+   end if ! if (masterproc)
 
 #if ( defined SPMD )
    call mpibcast(n_g_d, 1, mpiint, 0, mpicom, ierr)
@@ -234,175 +235,83 @@ subroutine cloud_rad_props_init()
    allocate(asm_sw_ice(n_g_d,nswbands))
    allocate(abs_lw_ice(n_g_d,nlwbands))
 
-   if(masterproc) then
-   call handle_ncerr( nf90_inq_varid(ncid, 'd_eff', d_id),&
-      'cloud optics deff get')
-   call handle_ncerr( nf90_get_var(ncid, d_id, g_d_eff),&
-      'read cloud optics deff values')
-
-   call handle_ncerr( nf90_inq_varid(ncid, 'sw_ext', ext_sw_ice_id),&
-      'cloud optics ext_sw_ice get')
-   call handle_ncerr(nf90_inquire_variable ( ncid, ext_sw_ice_id, ndims=ndims, dimids=vdimids),&
-       'checking dimensions of ext_sw_ice')
-   call handle_ncerr(nf90_inquire_dimension( ncid, vdimids(1), len=templen),&
-       'getting first dimension sw_ext')
-   !write(iulog,*) 'expected length',n_g_d,'actual len',templen
-   call handle_ncerr(nf90_inquire_dimension( ncid, vdimids(2), len=templen),&
-       'getting first dimension sw_ext')
-   !write(iulog,*) 'expected length',nswbands,'actual len',templen
-   call handle_ncerr( nf90_get_var(ncid, ext_sw_ice_id, ext_sw_ice),&
-      'read cloud optics ext_sw_ice values')
-
-   call handle_ncerr( nf90_inq_varid(ncid, 'sw_ssa', ssa_sw_ice_id),&
-      'cloud optics ssa_sw_ice get')
-   call handle_ncerr( nf90_get_var(ncid, ssa_sw_ice_id, ssa_sw_ice),&
-      'read cloud optics ssa_sw_ice values')
-
-   call handle_ncerr( nf90_inq_varid(ncid, 'sw_asm', asm_sw_ice_id),&
-      'cloud optics asm_sw_ice get')
-   call handle_ncerr( nf90_get_var(ncid, asm_sw_ice_id, asm_sw_ice),&
-      'read cloud optics asm_sw_ice values')
-
-   call handle_ncerr( nf90_inq_varid(ncid, 'lw_abs', abs_lw_ice_id),&
-      'cloud optics abs_lw_ice get')
-   call handle_ncerr( nf90_get_var(ncid, abs_lw_ice_id, abs_lw_ice),&
-      'read cloud optics abs_lw_ice values')
-
-   call handle_ncerr( nf90_close(ncid), 'ice optics file missing')
-
-   endif ! if masterproc
+   if (masterproc) then
+      call handle_ncerr( nf90_inq_varid(ncid, 'd_eff', d_id),&
+         'cloud optics deff get')
+      call handle_ncerr( nf90_get_var(ncid, d_id, g_d_eff),&
+         'read cloud optics deff values')
+
+      call handle_ncerr( nf90_inq_varid(ncid, 'sw_ext', ext_sw_ice_id),&
+         'cloud optics ext_sw_ice get')
+      call handle_ncerr(nf90_inquire_variable ( ncid, ext_sw_ice_id, ndims=ndims, dimids=vdimids),&
+         'checking dimensions of ext_sw_ice')
+      call handle_ncerr(nf90_inquire_dimension( ncid, vdimids(1), len=templen),&
+         'getting first dimension sw_ext')
+      call handle_ncerr(nf90_inquire_dimension( ncid, vdimids(2), len=templen),&
+         'getting first dimension sw_ext')
+      call handle_ncerr( nf90_get_var(ncid, ext_sw_ice_id, ext_sw_ice),&
+         'read cloud optics ext_sw_ice values')
+
+      call handle_ncerr( nf90_inq_varid(ncid, 'sw_ssa', ssa_sw_ice_id),&
+         'cloud optics ssa_sw_ice get')
+      call handle_ncerr( nf90_get_var(ncid, ssa_sw_ice_id, ssa_sw_ice),&
+         'read cloud optics ssa_sw_ice values')
+
+      call handle_ncerr( nf90_inq_varid(ncid, 'sw_asm', asm_sw_ice_id),&
+         'cloud optics asm_sw_ice get')
+      call handle_ncerr( nf90_get_var(ncid, asm_sw_ice_id, asm_sw_ice),&
+         'read cloud optics asm_sw_ice values')
+
+      call handle_ncerr( nf90_inq_varid(ncid, 'lw_abs', abs_lw_ice_id),&
+         'cloud optics abs_lw_ice get')
+      call handle_ncerr( nf90_get_var(ncid, abs_lw_ice_id, abs_lw_ice),&
+         'read cloud optics abs_lw_ice values')
+
+      call handle_ncerr( nf90_close(ncid), 'ice optics file missing')
+   end if ! if masterproc
+
 #if ( defined SPMD )
-    call mpibcast(g_d_eff, n_g_d, mpir8, 0, mpicom, ierr)
-    call mpibcast(ext_sw_ice, n_g_d*nswbands, mpir8, 0, mpicom, ierr)
-    call mpibcast(ssa_sw_ice, n_g_d*nswbands, mpir8, 0, mpicom, ierr)
-    call mpibcast(asm_sw_ice, n_g_d*nswbands, mpir8, 0, mpicom, ierr)
-    call mpibcast(abs_lw_ice, n_g_d*nlwbands, mpir8, 0, mpicom, ierr)
+   call mpibcast(g_d_eff, n_g_d, mpir8, 0, mpicom, ierr)
+   call mpibcast(ext_sw_ice, n_g_d*nswbands, mpir8, 0, mpicom, ierr)
+   call mpibcast(ssa_sw_ice, n_g_d*nswbands, mpir8, 0, mpicom, ierr)
+   call mpibcast(asm_sw_ice, n_g_d*nswbands, mpir8, 0, mpicom, ierr)
+   call mpibcast(abs_lw_ice, n_g_d*nlwbands, mpir8, 0, mpicom, ierr)
 #endif
 
-    return
+   return
 
 end subroutine cloud_rad_props_init
 
 !==============================================================================
 
-subroutine cloud_rad_props_get_sw(state, pbuf, &
-                                  tau, tau_w, tau_w_g, tau_w_f,&
-                                  diagnosticindex, oldliq, oldice)
+subroutine cloud_rad_props_get_lw(state, pbuf, cld_abs_od, oldliq, oldice, oldcloud)
 
-! return totaled (across all species) layer tau, omega, g, f
-! for all spectral interval for aerosols affecting the climate
-
-   ! Arguments
-   type(physics_state), intent(in)   :: state
-   type(physics_buffer_desc),pointer :: pbuf(:)
-   integer, optional,   intent(in) :: diagnosticindex      ! index (if present) to radiation diagnostic information
-
-   real(r8), intent(out) :: tau    (nswbands,pcols,pver) ! aerosol extinction optical depth
-   real(r8), intent(out) :: tau_w  (nswbands,pcols,pver) ! aerosol single scattering albedo * tau
-   real(r8), intent(out) :: tau_w_g(nswbands,pcols,pver) ! aerosol assymetry parameter * tau * w
-   real(r8), intent(out) :: tau_w_f(nswbands,pcols,pver) ! aerosol forward scattered fraction * tau * w
-
-   logical, optional, intent(in) :: oldliq,oldice
-
-   ! Local variables
-
-   integer :: ncol
-   integer :: lchnk
-   integer :: k, i    ! lev and daycolumn indices
-   integer :: iswband ! sw band indices
-
-   ! optical props for each aerosol
-   real(r8), pointer :: h_ext(:,:)
-   real(r8), pointer :: h_ssa(:,:)
-   real(r8), pointer :: h_asm(:,:)
-   real(r8), pointer :: n_ext(:)
-   real(r8), pointer :: n_ssa(:)
-   real(r8), pointer :: n_asm(:)
-
-   ! rad properties for liquid clouds
-   real(r8) :: liq_tau    (nswbands,pcols,pver) ! aerosol extinction optical depth
-   real(r8) :: liq_tau_w  (nswbands,pcols,pver) ! aerosol single scattering albedo * tau
-   real(r8) :: liq_tau_w_g(nswbands,pcols,pver) ! aerosol assymetry parameter * tau * w
-   real(r8) :: liq_tau_w_f(nswbands,pcols,pver) ! aerosol forward scattered fraction * tau * w
-
-   ! rad properties for ice clouds
-   real(r8) :: ice_tau    (nswbands,pcols,pver) ! aerosol extinction optical depth
-   real(r8) :: ice_tau_w  (nswbands,pcols,pver) ! aerosol single scattering albedo * tau
-   real(r8) :: ice_tau_w_g(nswbands,pcols,pver) ! aerosol assymetry parameter * tau * w
-   real(r8) :: ice_tau_w_f(nswbands,pcols,pver) ! aerosol forward scattered fraction * tau * w
-
-   !-----------------------------------------------------------------------------
-
-   ncol  = state%ncol
-   lchnk = state%lchnk
-
-   ! initialize to conditions that would cause failure
-   tau     (:,:,:) = -100._r8
-   tau_w   (:,:,:) = -100._r8
-   tau_w_g (:,:,:) = -100._r8
-   tau_w_f (:,:,:) = -100._r8
-
-   ! initialize layers to accumulate od's
-   tau    (:,1:ncol,:) = 0._r8
-   tau_w  (:,1:ncol,:) = 0._r8
-   tau_w_g(:,1:ncol,:) = 0._r8
-   tau_w_f(:,1:ncol,:) = 0._r8
-
-
-   call get_liquid_optics_sw(state, pbuf, liq_tau, liq_tau_w, liq_tau_w_g, liq_tau_w_f)
-
-   call get_ice_optics_sw   (state, pbuf, ice_tau, ice_tau_w, ice_tau_w_g, ice_tau_w_f)
-
-   tau    (:,1:ncol,:) =  liq_tau    (:,1:ncol,:) + ice_tau    (:,1:ncol,:)
-   tau_w  (:,1:ncol,:) =  liq_tau_w  (:,1:ncol,:) + ice_tau_w  (:,1:ncol,:)
-   tau_w_g(:,1:ncol,:) =  liq_tau_w_g(:,1:ncol,:) + ice_tau_w_g(:,1:ncol,:)
-   tau_w_f(:,1:ncol,:) =  liq_tau_w_f(:,1:ncol,:) + ice_tau_w_f(:,1:ncol,:)
-
-end subroutine cloud_rad_props_get_sw
-!==============================================================================
-
-subroutine cloud_rad_props_get_lw(state, pbuf, cld_abs_od, diagnosticindex, oldliq, oldice, oldcloud)
-
-! Purpose: Compute cloud longwave absorption optical depth
-!    cloud_rad_props_get_lw() is called by radlw()
+   ! Purpose: Compute cloud longwave absorption optical depth
 
    ! Arguments
    type(physics_state), intent(in)  :: state
    type(physics_buffer_desc),pointer:: pbuf(:)
    real(r8),            intent(out) :: cld_abs_od(nlwbands,pcols,pver) ! [fraction] absorption optical depth, per layer
-   integer, optional,   intent(in)  :: diagnosticindex
    logical, optional,   intent(in)  :: oldliq  ! use old liquid optics
    logical, optional,   intent(in)  :: oldice  ! use old ice optics
    logical, optional,   intent(in)  :: oldcloud  ! use old optics for both (b4b)
 
    ! Local variables
-
-   integer :: bnd_idx     ! LW band index
-   integer :: i           ! column index
-   integer :: k           ! lev index
    integer :: ncol        ! number of columns
-   integer :: lchnk
 
    ! rad properties for liquid clouds
    real(r8) :: liq_tau_abs_od(nlwbands,pcols,pver) ! liquid cloud absorption optical depth
 
    ! rad properties for ice clouds
    real(r8) :: ice_tau_abs_od(nlwbands,pcols,pver) ! ice cloud absorption optical depth
-
    !-----------------------------------------------------------------------------
 
    ncol = state%ncol
-   lchnk = state%lchnk
 
-   ! compute optical depths cld_absod
    cld_abs_od = 0._r8
 
    if(present(oldcloud))then
       if(oldcloud) then
-         ! make diagnostic calls to these first to output ice and liq OD's
-         !call old_liq_get_rad_props_lw(state, pbuf, liq_tau_abs_od, oldliqwp=.false.)
-         !call old_ice_get_rad_props_lw(state, pbuf, ice_tau_abs_od, oldicewp=.false.)
-         ! This affects climate (cld_abs_od)
          call oldcloud_lw(state,pbuf,cld_abs_od,oldwp=.false.)
          return
       endif
@@ -434,13 +343,36 @@ end subroutine cloud_rad_props_get_lw
 
 !==============================================================================
 
+subroutine get_ice_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
+   type(physics_state), intent(in)   :: state
+   type(physics_buffer_desc),pointer :: pbuf(:)
+
+   real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
+   real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
+   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
+   real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
+
+   real(r8), pointer :: iciwpth(:,:), dei(:,:)
+
+   ! Get relevant pbuf fields, and interpolate optical properties from
+   ! the lookup tables.
+   call pbuf_get_field(pbuf, i_iciwp, iciwpth)
+   call pbuf_get_field(pbuf, i_dei,   dei)
+
+   call interpolate_ice_optics_sw(state%ncol, iciwpth, dei, tau, tau_w, &
+        tau_w_g, tau_w_f)
+
+end subroutine get_ice_optics_sw
+
+!==============================================================================
+
 subroutine get_snow_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
    type(physics_state), intent(in)   :: state
    type(physics_buffer_desc),pointer :: pbuf(:)
 
    real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
    real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
+   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
    real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
 
    real(r8), pointer :: icswpth(:,:), des(:,:)
@@ -463,12 +395,13 @@ subroutine get_grau_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
 
    real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
    real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
+   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
    real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
 
    real(r8), pointer :: icgrauwpth(:,:), degrau(:,:)
 
    integer :: i,k
+   character(len=*), parameter :: sub = 'get_grau_optics_sw'
 
    ! This does the same thing as get_ice_optics_sw, except with a different
    ! water path and effective diameter.
@@ -489,87 +422,11 @@ subroutine get_grau_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
       enddo
 
    else
-      call endrun('ERROR: Get_grau_optics_sw called when graupel properties not supported')
+      call endrun(sub//': ERROR: Get_grau_optics_sw called when graupel properties not supported')
    end if
 
 end subroutine get_grau_optics_sw
 
-!==============================================================================
-! Private methods
-!==============================================================================
-
-subroutine get_ice_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
-   type(physics_state), intent(in)   :: state
-   type(physics_buffer_desc),pointer :: pbuf(:)
-
-   real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
-   real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
-   real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
-
-   real(r8), pointer :: iciwpth(:,:), dei(:,:)
-
-   ! Get relevant pbuf fields, and interpolate optical properties from
-   ! the lookup tables.
-   call pbuf_get_field(pbuf, i_iciwp, iciwpth)
-   call pbuf_get_field(pbuf, i_dei,   dei)
-
-   call interpolate_ice_optics_sw(state%ncol, iciwpth, dei, tau, tau_w, &
-        tau_w_g, tau_w_f)
-
-end subroutine get_ice_optics_sw
-
-!==============================================================================
-
-subroutine interpolate_ice_optics_sw(ncol, iciwpth, dei, tau, tau_w, &
-     tau_w_g, tau_w_f)
-
-  integer, intent(in) :: ncol
-  real(r8), intent(in) :: iciwpth(pcols,pver)
-  real(r8), intent(in) :: dei(pcols,pver)
-
-  real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
-  real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-  real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
-  real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
-
-  type(interp_type) :: dei_wgts
-
-  integer :: i, k, swband
-  real(r8) :: ext(nswbands), ssa(nswbands), asm(nswbands)
-
-  do k = 1,pver
-     do i = 1,ncol
-        if( iciwpth(i,k) < 1.e-80_r8 .or. dei(i,k) == 0._r8) then
-           ! if ice water path is too small, OD := 0
-           tau    (:,i,k) = 0._r8
-           tau_w  (:,i,k) = 0._r8
-           tau_w_g(:,i,k) = 0._r8
-           tau_w_f(:,i,k) = 0._r8
-        else
-           ! for each cell interpolate to find weights in g_d_eff grid.
-           call lininterp_init(g_d_eff, n_g_d, dei(i:i,k), 1, &
-                extrap_method_bndry, dei_wgts)
-           ! interpolate into grid and extract radiative properties
-           do swband = 1, nswbands
-              call lininterp(ext_sw_ice(:,swband), n_g_d, &
-                   ext(swband:swband), 1, dei_wgts)
-              call lininterp(ssa_sw_ice(:,swband), n_g_d, &
-                   ssa(swband:swband), 1, dei_wgts)
-              call lininterp(asm_sw_ice(:,swband), n_g_d, &
-                   asm(swband:swband), 1, dei_wgts)
-           end do
-           tau    (:,i,k) = iciwpth(i,k) * ext
-           tau_w  (:,i,k) = tau(:,i,k) * ssa
-           tau_w_g(:,i,k) = tau_w(:,i,k) * asm
-           tau_w_f(:,i,k) = tau_w_g(:,i,k) * asm
-           call lininterp_finish(dei_wgts)
-        endif
-     enddo
-  enddo
-
-end subroutine interpolate_ice_optics_sw
-
 !==============================================================================
 
 subroutine get_liquid_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
@@ -578,14 +435,13 @@ subroutine get_liquid_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f)
 
    real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
    real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! asymetry parameter * tau * w
+   real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
    real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
 
    real(r8), pointer, dimension(:,:) :: lamc, pgam, iclwpth
    real(r8), dimension(pcols,pver) :: kext
-   integer i,k,swband,lchnk,ncol
+   integer i,k,swband, ncol
 
-   lchnk = state%lchnk
    ncol = state%ncol
 
 
@@ -616,14 +472,13 @@ subroutine liquid_cloud_get_rad_props_lw(state, pbuf, abs_od)
    type(physics_buffer_desc),pointer  :: pbuf(:)
    real(r8), intent(out) :: abs_od(nlwbands,pcols,pver)
 
-   integer :: lchnk, ncol
+   integer :: ncol
    real(r8), pointer, dimension(:,:) :: lamc, pgam, iclwpth
 
    integer lwband, i, k
 
    abs_od = 0._r8
 
-   lchnk = state%lchnk
    ncol = state%ncol
 
    call pbuf_get_field(pbuf, i_lambda,  lamc)
@@ -668,6 +523,7 @@ subroutine grau_cloud_get_rad_props_lw(state, pbuf, abs_od)
    real(r8), intent(out) :: abs_od(nlwbands,pcols,pver)
 
    real(r8), pointer :: icgrauwpth(:,:), degrau(:,:)
+   character(len=*), parameter :: sub = 'grau_cloud_get_rad_props_lw'
 
    ! This does the same thing as ice_cloud_get_rad_props_lw, except with a
    ! different water path and effective diameter.
@@ -677,7 +533,7 @@ subroutine grau_cloud_get_rad_props_lw(state, pbuf, abs_od)
 
       call interpolate_ice_optics_lw(state%ncol,icgrauwpth, degrau, abs_od)
    else
-      call endrun('ERROR: Grau_cloud_get_rad_props_lw called when graupel &
+      call endrun(sub//': ERROR: Grau_cloud_get_rad_props_lw called when graupel &
            &properties not supported')
    end if
 
@@ -701,6 +557,59 @@ subroutine ice_cloud_get_rad_props_lw(state, pbuf, abs_od)
 
 end subroutine ice_cloud_get_rad_props_lw
 
+!==============================================================================
+! Private methods
+!==============================================================================
+
+subroutine interpolate_ice_optics_sw(ncol, iciwpth, dei, tau, tau_w, &
+     tau_w_g, tau_w_f)
+
+  integer, intent(in) :: ncol
+  real(r8), intent(in) :: iciwpth(pcols,pver)
+  real(r8), intent(in) :: dei(pcols,pver)
+
+  real(r8),intent(out) :: tau    (nswbands,pcols,pver) ! extinction optical depth
+  real(r8),intent(out) :: tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
+  real(r8),intent(out) :: tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
+  real(r8),intent(out) :: tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
+
+  type(interp_type) :: dei_wgts
+
+  integer :: i, k, swband
+  real(r8) :: ext(nswbands), ssa(nswbands), asm(nswbands)
+
+  do k = 1,pver
+     do i = 1,ncol
+        if( iciwpth(i,k) < tiny .or. dei(i,k) == 0._r8) then
+           ! if ice water path is too small, OD := 0
+           tau    (:,i,k) = 0._r8
+           tau_w  (:,i,k) = 0._r8
+           tau_w_g(:,i,k) = 0._r8
+           tau_w_f(:,i,k) = 0._r8
+        else
+           ! for each cell interpolate to find weights in g_d_eff grid.
+           call lininterp_init(g_d_eff, n_g_d, dei(i:i,k), 1, &
+                extrap_method_bndry, dei_wgts)
+           ! interpolate into grid and extract radiative properties
+           do swband = 1, nswbands
+              call lininterp(ext_sw_ice(:,swband), n_g_d, &
+                   ext(swband:swband), 1, dei_wgts)
+              call lininterp(ssa_sw_ice(:,swband), n_g_d, &
+                   ssa(swband:swband), 1, dei_wgts)
+              call lininterp(asm_sw_ice(:,swband), n_g_d, &
+                   asm(swband:swband), 1, dei_wgts)
+           end do
+           tau    (:,i,k) = iciwpth(i,k) * ext
+           tau_w  (:,i,k) = tau(:,i,k) * ssa
+           tau_w_g(:,i,k) = tau_w(:,i,k) * asm
+           tau_w_f(:,i,k) = tau_w_g(:,i,k) * asm
+           call lininterp_finish(dei_wgts)
+        endif
+     enddo
+  enddo
+
+end subroutine interpolate_ice_optics_sw
+
 !==============================================================================
 
 subroutine interpolate_ice_optics_lw(ncol, iciwpth, dei, abs_od)
@@ -719,7 +628,7 @@ subroutine interpolate_ice_optics_lw(ncol, iciwpth, dei, abs_od)
   do k = 1,pver
      do i = 1,ncol
         ! if ice water path is too small, OD := 0
-        if( iciwpth(i,k) < 1.e-80_r8 .or. dei(i,k) == 0._r8) then
+        if( iciwpth(i,k) < tiny .or. dei(i,k) == 0._r8) then
            abs_od (:,i,k) = 0._r8
         else
            ! for each cell interpolate to find weights in g_d_eff grid.
@@ -752,7 +661,7 @@ subroutine gam_liquid_lw(clwptn, lamc, pgam, abs_od)
   type(interp_type) :: mu_wgts
   type(interp_type) :: lambda_wgts
 
-  if (clwptn < 1.e-80_r8) then
+  if (clwptn < tiny) then
     abs_od = 0._r8
     return
   endif
@@ -786,7 +695,7 @@ subroutine gam_liquid_sw(clwptn, lamc, pgam, tau, tau_w, tau_w_g, tau_w_f)
   type(interp_type) :: mu_wgts
   type(interp_type) :: lambda_wgts
 
-  if (clwptn < 1.e-80_r8) then
+  if (clwptn < tiny) then
     tau = 0._r8
     tau_w = 0._r8
     tau_w_g = 0._r8
diff --git a/src/physics/cam/cospsimulator_intr.F90 b/src/physics/cam/cospsimulator_intr.F90
index 855a8e82d5..6a01415f04 100644
--- a/src/physics/cam/cospsimulator_intr.F90
+++ b/src/physics/cam/cospsimulator_intr.F90
@@ -1107,7 +1107,7 @@ subroutine cospsimulator_intr_init()
             flag_xyfill=.true., fill_value=R_UNDEF)
        call addfld ('MODIS_fracliq',   (/'cosp_scol','lev      '/), 'I','1',      'Fraction of tau from liquid water',  &
             flag_xyfill=.true., fill_value=R_UNDEF)
-       call addfld ('MODIS_asym',      (/'cosp_scol','lev      '/), 'I','1',      'Assymetry parameter (MODIS)',        &
+       call addfld ('MODIS_asym',      (/'cosp_scol','lev      '/), 'I','1',      'Asymmetry parameter (MODIS)',        &
             flag_xyfill=.true., fill_value=R_UNDEF)
        call addfld ('MODIS_ssa',       (/'cosp_scol','lev      '/), 'I','1',      'Single-scattering albedo (MODIS)',   &
             flag_xyfill=.true., fill_value=R_UNDEF)
@@ -3262,7 +3262,7 @@ subroutine subsample_and_optics(nPoints, nLevels, nColumns, nHydro,overlap,
             MODIS_snowSize, cospIN%tau_067, MODIS_opticalThicknessLiq,               &
             MODIS_opticalThicknessIce, MODIS_opticalThicknessSnow)                            
        
-       ! Compute assymetry parameter and single scattering albedo 
+       ! Compute asymmetry parameter and single scattering albedo 
        call modis_optics(nPoints, nLevels, nColumns, MODIS_opticalThicknessLiq,      &
             MODIS_waterSize*1.0e6_wp, MODIS_opticalThicknessIce,                     &
             MODIS_iceSize*1.0e6_wp, MODIS_opticalThicknessSnow,                      &
diff --git a/src/physics/rrtmg/ebert_curry.F90 b/src/physics/cam/ebert_curry_ice_optics.F90
similarity index 59%
rename from src/physics/rrtmg/ebert_curry.F90
rename to src/physics/cam/ebert_curry_ice_optics.F90
index a1e1c031b1..8d9b4985a7 100644
--- a/src/physics/rrtmg/ebert_curry.F90
+++ b/src/physics/cam/ebert_curry_ice_optics.F90
@@ -1,15 +1,14 @@
-module ebert_curry
+module ebert_curry_ice_optics
 
-!------------------------------------------------------------------------------------------------
-!------------------------------------------------------------------------------------------------
 
 use shr_kind_mod,     only: r8 => shr_kind_r8
-use ppgrid,           only: pcols, pver, pverp
+use physconst,        only: gravit
+use ppgrid,           only: pcols, pver
 use physics_types,    only: physics_state
 use physics_buffer,   only: physics_buffer_desc, pbuf_get_index, pbuf_get_field, pbuf_old_tim_idx
-use radconstants,     only: nswbands, nlwbands, idx_sw_diag, ot_length, idx_lw_diag, get_sw_spectral_boundaries
+use constituents,     only: cnst_get_ind
+use radconstants,     only: nswbands, nlwbands, get_sw_spectral_boundaries
 use cam_abortutils,   only: endrun
-use cam_history,      only: outfld
 
 implicit none
 private
@@ -17,41 +16,21 @@ module ebert_curry
 
 public :: &
    ec_rad_props_init,        &
-   cloud_rad_props_get_sw, & ! return SW optical props of total bulk aerosols
-   cloud_rad_props_get_lw, & ! return LW optical props of total bulk aerosols
    ec_ice_optics_sw,       &
    ec_ice_get_rad_props_lw
 
 
 real(r8), public, parameter:: scalefactor = 1._r8 !500._r8/917._r8
 
-! Minimum cloud amount (as a fraction of the grid-box area) to 
-! distinguish from clear sky
-! 
-   real(r8) cldmin
-   parameter (cldmin = 1.0e-80_r8)
-!
-! Decimal precision of cloud amount (0 -> preserve full resolution;
-! 10^-n -> preserve n digits of cloud amount)
-! 
-   real(r8) cldeps
-   parameter (cldeps = 0.0_r8)
-
-! 
-! indexes into pbuf for optical parameters of MG clouds
-! 
-   integer :: dei_idx     = 0 
-   integer :: mu_idx      = 0
-   integer :: lambda_idx  = 0 
-   integer :: iciwp_idx   = 0 
-   integer :: iclwp_idx   = 0 
-   integer :: cld_idx     = 0  
-   integer :: rei_idx     = 0  
-
-! indexes into constituents for old optics
-   integer :: &
-        ixcldice,           & ! cloud ice water index
-        ixcldliq              ! cloud liquid water index
+! indices into pbuf
+integer :: iciwp_idx   = 0 
+integer :: iclwp_idx   = 0 
+integer :: cld_idx     = 0  
+integer :: rei_idx     = 0  
+
+! indices into constituents for old optics
+integer :: ixcldice  ! cloud ice water index
+integer :: ixcldliq  ! cloud liquid water index
 
 
 !==============================================================================
@@ -60,17 +39,6 @@ module ebert_curry
 
 subroutine ec_rad_props_init()
 
-!   use cam_history, only: addfld
-   use netcdf
-   use spmd_utils,     only: masterproc
-   use ioFileMod,      only: getfil
-   use cam_logfile,    only: iulog
-   use error_messages, only: handle_ncerr
-#if ( defined SPMD )
-   use mpishorthand
-#endif
-   use constituents,   only: cnst_get_ind
-
    integer :: err
 
    iciwp_idx  = pbuf_get_index('ICIWP',errcode=err)
@@ -82,124 +50,18 @@ subroutine ec_rad_props_init()
    call cnst_get_ind('CLDICE', ixcldice)
    call cnst_get_ind('CLDLIQ', ixcldliq)
 
-   !call addfld ('CLWPTH_OLD',(/ 'lev' /), 'I','Kg/m2','old In Cloud Liquid Water Path', sampling_seq='rad_lwsw')
-   !call addfld ('KEXT_OLD',(/ 'lev' /),'I','m^2/kg','old extinction')
-   !call addfld ('CLDOD_OLD',(/ 'lev' /),'I','1','old liquid OD')
-   !call addfld ('REL_OLD',(/ 'lev' /),'I','1','old liquid effective radius (liquid)')
-
-   !call addfld ('CLWPTH_NEW',(/ 'lev' /), 'I','Kg/m2','In Cloud Liquid Water Path', sampling_seq='rad_lwsw')
-   !call addfld ('KEXT_NEW',(/ 'lev' /),'I','m^2/kg','extinction')
-   !call addfld ('CLDOD_NEW',(/ 'lev' /),'I','1','liquid OD')
-
-   !call addfld('CIWPTH_NEW',(/ 'lev' /), 'I','Kg/m2','In Cloud Ice Water Path', sampling_seq='rad_lwsw')
-   !call addfld('CIWPTH_OLD',(/ 'lev' /), 'I','Kg/m2','In Cloud Ice Water Path (old)', sampling_seq='rad_lwsw')
-
-    return
-
 end subroutine ec_rad_props_init
 
 !==============================================================================
 
-subroutine cloud_rad_props_get_sw(state, pbuf, &
-                                  tau, tau_w, tau_w_g, tau_w_f,&
-                                  diagnosticindex, oldliq, oldice)
-
-! return totaled (across all species) layer tau, omega, g, f 
-! for all spectral interval for aerosols affecting the climate
-
-   ! Arguments
-   type(physics_state), intent(in) :: state
-   type(physics_buffer_desc),  pointer :: pbuf(:)
-   integer, optional,   intent(in) :: diagnosticindex      ! index (if present) to radiation diagnostic information
-
-   real(r8), intent(out) :: tau    (nswbands,pcols,pver) ! aerosol extinction optical depth
-   real(r8), intent(out) :: tau_w  (nswbands,pcols,pver) ! aerosol single scattering albedo * tau
-   real(r8), intent(out) :: tau_w_g(nswbands,pcols,pver) ! aerosol assymetry parameter * tau * w
-   real(r8), intent(out) :: tau_w_f(nswbands,pcols,pver) ! aerosol forward scattered fraction * tau * w
-
-   logical, optional, intent(in) :: oldliq,oldice
-
-   ! Local variables
-
-   integer :: ncol
-   integer :: lchnk
-   integer :: k, i    ! lev and daycolumn indices
-   integer :: iswband ! sw band indices
-
-   !-----------------------------------------------------------------------------
-
-   ncol  = state%ncol
-   lchnk = state%lchnk
-
-   ! initialize to conditions that would cause failure
-   tau     (:,:,:) = -100._r8
-   tau_w   (:,:,:) = -100._r8
-   tau_w_g (:,:,:) = -100._r8
-   tau_w_f (:,:,:) = -100._r8
-
-   ! initialize layers to accumulate od's
-   tau    (:,1:ncol,:) = 0._r8
-   tau_w  (:,1:ncol,:) = 0._r8
-   tau_w_g(:,1:ncol,:) = 0._r8
-   tau_w_f(:,1:ncol,:) = 0._r8
-
-
-   call ec_ice_optics_sw   (state, pbuf, tau, tau_w, tau_w_g, tau_w_f, oldicewp=.true.)
-!  call outfld ('CI_OD_SW_OLD', ice_tau(idx_sw_diag,:,:), pcols, lchnk)
-
-
-end subroutine cloud_rad_props_get_sw
-!==============================================================================
-
-subroutine cloud_rad_props_get_lw(state, pbuf, cld_abs_od, diagnosticindex, oldliq, oldice, oldcloud)
-
-! Purpose: Compute cloud longwave absorption optical depth
-!    cloud_rad_props_get_lw() is called by radlw() 
-
-   ! Arguments
-   type(physics_state), intent(in)  :: state
-   type(physics_buffer_desc), pointer  :: pbuf(:)
-   real(r8),            intent(out) :: cld_abs_od(nlwbands,pcols,pver) ! [fraction] absorption optical depth, per layer
-   integer, optional,   intent(in)  :: diagnosticindex
-   logical, optional,   intent(in)  :: oldliq  ! use old liquid optics
-   logical, optional,   intent(in)  :: oldice  ! use old ice optics
-   logical, optional,   intent(in)  :: oldcloud  ! use old optics for both (b4b)
-
-   ! Local variables
-
-   integer :: bnd_idx     ! LW band index
-   integer :: i           ! column index
-   integer :: k           ! lev index
-   integer :: ncol        ! number of columns
-   integer :: lchnk
-
-   !-----------------------------------------------------------------------------
-
-   ncol = state%ncol
-   lchnk = state%lchnk
-
-   ! compute optical depths cld_absod 
-   cld_abs_od = 0._r8
-
-   call ec_ice_get_rad_props_lw(state, pbuf, cld_abs_od, oldicewp=.true.)
-   !call outfld('CI_OD_LW_OLD', ice_tau_abs_od(idx_lw_diag ,:,:), pcols, lchnk)
-      
-end subroutine cloud_rad_props_get_lw
-
-!==============================================================================
-! Private methods
-!==============================================================================
-
 subroutine ec_ice_optics_sw   (state, pbuf, ice_tau, ice_tau_w, ice_tau_w_g, ice_tau_w_f, oldicewp)
 
-   use physconst,      only: gravit
-
-   type(physics_state), intent(in) :: state
+   type(physics_state),    intent(in) :: state
    type(physics_buffer_desc), pointer :: pbuf(:)
 
    real(r8),intent(out) :: ice_tau    (nswbands,pcols,pver) ! extinction optical depth
    real(r8),intent(out) :: ice_tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: ice_tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
+   real(r8),intent(out) :: ice_tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
    real(r8),intent(out) :: ice_tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
    logical, intent(in) :: oldicewp
 
@@ -312,10 +174,10 @@ subroutine ec_ice_optics_sw   (state, pbuf, ice_tau, ice_tau_w, ice_tau_w_g, ice
    end do ! nswbands
 
 end subroutine ec_ice_optics_sw
+
 !==============================================================================
 
 subroutine ec_ice_get_rad_props_lw(state, pbuf, abs_od, oldicewp)
-   use physconst,      only: gravit
 
    type(physics_state), intent(in)   :: state
    type(physics_buffer_desc),pointer :: pbuf(:)
@@ -390,19 +252,13 @@ subroutine ec_ice_get_rad_props_lw(state, pbuf, abs_od, oldicewp)
           cldtau(i,k) = kabs*cwp(i,k)
        end do
    end do
-!
+
    do lwband = 1,nlwbands
       abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
    enddo
 
-   !if(oldicewp) then
-   !  call outfld('CIWPTH_OLD',cicewp(:,:)/1000,pcols,lchnk)
-   !else
-   !  call outfld('CIWPTH_OLD',iciwpth(:,:),pcols,lchnk)
-   !endif
-   !call outfld('CI_OD_LW_OLD',cldtau(:,:),pcols,lchnk)
-
 end subroutine ec_ice_get_rad_props_lw
+
 !==============================================================================
 
-end module ebert_curry
+end module ebert_curry_ice_optics
diff --git a/src/physics/cam/oldcloud_optics.F90 b/src/physics/cam/oldcloud_optics.F90
new file mode 100644
index 0000000000..bf53856ad6
--- /dev/null
+++ b/src/physics/cam/oldcloud_optics.F90
@@ -0,0 +1,324 @@
+module oldcloud_optics
+
+!------------------------------------------------------------------------------------------------
+!------------------------------------------------------------------------------------------------
+
+use shr_kind_mod,     only: r8 => shr_kind_r8
+use ppgrid,           only: pcols, pver, pverp
+use physics_types,    only: physics_state
+use physics_buffer,   only: physics_buffer_desc, pbuf_get_index, pbuf_old_tim_idx, pbuf_get_field
+use constituents,     only: cnst_get_ind
+use physconst,        only: gravit
+use radconstants,     only: nlwbands
+use ebert_curry_ice_optics, only: scalefactor
+
+use cam_abortutils,   only: endrun
+
+implicit none
+private
+save
+
+public :: &
+   oldcloud_init,            &
+   oldcloud_lw,              &
+   old_liq_get_rad_props_lw, &
+   old_ice_get_rad_props_lw
+
+integer :: nmu, nlambda
+real(r8), allocatable :: g_mu(:)           ! mu samples on grid
+real(r8), allocatable :: g_lambda(:,:)     ! lambda scale samples on grid
+real(r8), allocatable :: ext_sw_liq(:,:,:)
+real(r8), allocatable :: ssa_sw_liq(:,:,:)
+real(r8), allocatable :: asm_sw_liq(:,:,:)
+real(r8), allocatable :: abs_lw_liq(:,:,:)
+
+integer :: n_g_d
+real(r8), allocatable :: g_d_eff(:)        ! radiative effective diameter samples on grid
+real(r8), allocatable :: ext_sw_ice(:,:)
+real(r8), allocatable :: ssa_sw_ice(:,:)
+real(r8), allocatable :: asm_sw_ice(:,:)
+real(r8), allocatable :: abs_lw_ice(:,:)
+
+! Minimum cloud amount (as a fraction of the grid-box area) to 
+! distinguish from clear sky
+real(r8), parameter :: cldmin = 1.0e-80_r8
+
+! Decimal precision of cloud amount (0 -> preserve full resolution;
+! 10^-n -> preserve n digits of cloud amount)
+real(r8), parameter :: cldeps = 0.0_r8
+
+! indexes into pbuf
+integer :: iciwp_idx   = 0 
+integer :: iclwp_idx   = 0 
+integer :: cld_idx     = 0 
+integer :: rel_idx     = 0 
+integer :: rei_idx     = 0 
+
+! indexes into constituents for old optics
+integer :: &
+   ixcldice, & ! cloud ice water index
+   ixcldliq    ! cloud liquid water index
+
+
+!==============================================================================
+contains
+!==============================================================================
+
+subroutine oldcloud_init()
+
+
+   integer :: err
+
+   iciwp_idx  = pbuf_get_index('ICIWP',errcode=err)
+   iclwp_idx  = pbuf_get_index('ICLWP',errcode=err)
+   cld_idx    = pbuf_get_index('CLD')
+   rel_idx    = pbuf_get_index('REL')
+   rei_idx    = pbuf_get_index('REI')
+
+   ! old optics
+   call cnst_get_ind('CLDICE', ixcldice)
+   call cnst_get_ind('CLDLIQ', ixcldliq)
+
+end subroutine oldcloud_init
+
+!==============================================================================
+
+subroutine oldcloud_lw(state,pbuf,cld_abs_od,oldwp)
+
+   type(physics_state), intent(in) :: state
+   type(physics_buffer_desc),pointer :: pbuf(:)
+   real(r8),            intent(out) :: cld_abs_od(nlwbands,pcols,pver) ! [fraction] absorption optical depth, per layer
+   logical,intent(in)              :: oldwp ! use old definition of waterpath
+
+
+   real(r8) :: gicewp(pcols,pver)
+   real(r8) :: gliqwp(pcols,pver)
+   real(r8) :: cicewp(pcols,pver)
+   real(r8) :: cliqwp(pcols,pver)
+   real(r8) :: ficemr(pcols,pver)
+   real(r8) :: cwp(pcols,pver)
+   real(r8) :: cldtau(pcols,pver)
+
+   real(r8), pointer, dimension(:,:) :: cldn
+   real(r8), pointer, dimension(:,:) :: rei 
+   integer :: ncol, itim_old, lwband, i, k, lchnk
+   real(r8), pointer, dimension(:,:) :: iclwpth, iciwpth
+
+   real(r8) :: kabs, kabsi
+   real(r8), parameter :: kabsl = 0.090361_r8 ! longwave liquid absorption coeff (m**2/g)
+
+ 
+   ncol = state%ncol
+   lchnk = state%lchnk
+
+   itim_old  =  pbuf_old_tim_idx()
+   call pbuf_get_field(pbuf, rei_idx,   rei)
+   call pbuf_get_field(pbuf, cld_idx,   cldn,   start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
+
+   if (oldwp) then
+     do k=1,pver
+         do i = 1,ncol
+            gicewp(i,k) = state%q(i,k,ixcldice)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box ice water path.
+            gliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box liquid water path.
+            cicewp(i,k) = gicewp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud ice water path.
+            cliqwp(i,k) = gliqwp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud liquid water path.
+            ficemr(i,k) = state%q(i,k,ixcldice) /                 &
+                 max(1.e-10_r8,(state%q(i,k,ixcldice)+state%q(i,k,ixcldliq)))
+         end do
+     end do
+     cwp(:ncol,:pver) = cicewp(:ncol,:pver) + cliqwp(:ncol,:pver)
+   else
+      if (iclwp_idx<=0 .or. iciwp_idx<=0) then 
+         call endrun('oldcloud_lw: oldwp must be set to true since ICIWP and/or ICLWP were not found in pbuf')
+      endif
+      call pbuf_get_field(pbuf, iclwp_idx, iclwpth)
+      call pbuf_get_field(pbuf, iciwp_idx, iciwpth)
+      do k=1,pver
+         do i = 1,ncol
+            cwp(i,k) = 1000.0_r8 *iclwpth(i,k) + 1000.0_r8 *iciwpth(i, k)
+            ficemr(i,k) = 1000.0_r8 * iciwpth(i,k)/(max(1.e-18_r8,cwp(i,k)))
+         end do
+      end do
+   endif
+
+   do k=1,pver
+       do i=1,ncol
+
+          !note that optical properties for ice valid only
+          !in range of 13 > rei > 130 micron (Ebert and Curry 92)
+          kabsi = 0.005_r8 + 1._r8/min(max(13._r8,scalefactor*rei(i,k)),130._r8)
+          kabs = kabsl*(1._r8-ficemr(i,k)) + kabsi*ficemr(i,k)
+          cldtau(i,k) = kabs*cwp(i,k)
+       end do
+   end do
+!
+   do lwband = 1,nlwbands
+      cld_abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
+   enddo
+
+end subroutine oldcloud_lw
+
+!==============================================================================
+
+subroutine old_liq_get_rad_props_lw(state, pbuf, abs_od, oldliqwp)
+
+   type(physics_state), intent(in)  :: state
+   type(physics_buffer_desc),pointer  :: pbuf(:)
+   real(r8), intent(out) :: abs_od(nlwbands,pcols,pver)
+   logical, intent(in) :: oldliqwp
+
+   real(r8) :: gicewp(pcols,pver)
+   real(r8) :: gliqwp(pcols,pver)
+   real(r8) :: cicewp(pcols,pver)
+   real(r8) :: cliqwp(pcols,pver)
+   real(r8) :: ficemr(pcols,pver)
+   real(r8) :: cwp(pcols,pver)
+   real(r8) :: cldtau(pcols,pver)
+   
+   real(r8), pointer, dimension(:,:) :: cldn
+   real(r8), pointer, dimension(:,:) :: rei
+   integer :: ncol, itim_old, lwband, i, k, lchnk 
+
+   real(r8) :: kabs, kabsi
+   real(r8), parameter :: kabsl = 0.090361_r8 ! longwave liquid absorption coeff (m**2/g)
+
+   real(r8), pointer, dimension(:,:) :: iclwpth, iciwpth
+
+   ncol=state%ncol
+   lchnk = state%lchnk
+
+   itim_old  =  pbuf_old_tim_idx()
+   call pbuf_get_field(pbuf, rei_idx,   rei)
+   call pbuf_get_field(pbuf, cld_idx,   cldn,   start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
+
+   if (oldliqwp) then
+     do k=1,pver
+         do i = 1,ncol
+            gicewp(i,k) = state%q(i,k,ixcldice)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box ice water path.
+            gliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box liquid water path.
+            cicewp(i,k) = gicewp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud ice water path.
+            cliqwp(i,k) = gliqwp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud liquid water path.
+            ficemr(i,k) = state%q(i,k,ixcldice) /                 &
+                 max(1.e-10_r8,(state%q(i,k,ixcldice)+state%q(i,k,ixcldliq)))
+         end do
+     end do
+     cwp(:ncol,:pver) = cicewp(:ncol,:pver) + cliqwp(:ncol,:pver)
+   else
+      if (iclwp_idx<=0 .or. iciwp_idx<=0) then 
+         call endrun('old_liq_get_rad_props_lw: oldliqwp must be set to true since ICIWP and/or ICLWP were not found in pbuf')
+      endif
+      call pbuf_get_field(pbuf, iclwp_idx, iclwpth)
+      call pbuf_get_field(pbuf, iciwp_idx, iciwpth)
+      do k=1,pver
+         do i = 1,ncol
+            cwp(i,k) = 1000.0_r8 *iclwpth(i,k) + 1000.0_r8 *iciwpth(i, k)
+            ficemr(i,k) = 1000.0_r8 * iciwpth(i,k)/(max(1.e-18_r8,cwp(i,k)))
+         end do
+      end do
+   endif
+
+
+   do k=1,pver
+       do i=1,ncol
+
+          ! Note from Andrew Conley:
+          !  Optics for RK no longer supported, This is constructed to get
+          !  close to bit for bit.  Otherwise we could simply use liquid water path
+          !note that optical properties for ice valid only
+          !in range of 13 > rei > 130 micron (Ebert and Curry 92)
+          kabsi = 0.005_r8 + 1._r8/min(max(13._r8,scalefactor*rei(i,k)),130._r8)
+          kabs = kabsl*(1._r8-ficemr(i,k)) ! + kabsi*ficemr(i,k)
+          cldtau(i,k) = kabs*cwp(i,k)
+       end do
+   end do
+
+   do lwband = 1,nlwbands
+      abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
+   enddo
+
+
+end subroutine old_liq_get_rad_props_lw
+
+!==============================================================================
+
+subroutine old_ice_get_rad_props_lw(state, pbuf, abs_od, oldicewp)
+
+   type(physics_state), intent(in)  :: state
+   type(physics_buffer_desc),pointer  :: pbuf(:)
+    real(r8), intent(out) :: abs_od(nlwbands,pcols,pver)
+   logical, intent(in) :: oldicewp
+
+   real(r8) :: gicewp(pcols,pver)
+   real(r8) :: gliqwp(pcols,pver)
+   real(r8) :: cicewp(pcols,pver)
+   real(r8) :: cliqwp(pcols,pver)
+   real(r8) :: ficemr(pcols,pver)
+   real(r8) :: cwp(pcols,pver)
+   real(r8) :: cldtau(pcols,pver)
+
+   real(r8), pointer, dimension(:,:) :: cldn
+   real(r8), pointer, dimension(:,:) :: rei
+   integer :: ncol, itim_old, lwband, i, k, lchnk
+
+   real(r8) :: kabs, kabsi
+   real(r8), parameter :: kabsl = 0.090361_r8 ! longwave liquid absorption coeff (m**2/g)
+
+   real(r8), pointer, dimension(:,:) :: iclwpth, iciwpth
+
+
+   ncol = state%ncol
+   lchnk = state%lchnk
+
+   itim_old  =  pbuf_old_tim_idx()
+   call pbuf_get_field(pbuf, rei_idx,   rei)
+   call pbuf_get_field(pbuf, cld_idx,   cldn,   start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
+
+   if(oldicewp) then
+     do k=1,pver
+         do i = 1,ncol
+            gicewp(i,k) = state%q(i,k,ixcldice)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box ice water path.
+            gliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box liquid water path.
+            cicewp(i,k) = gicewp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud ice water path.
+            cliqwp(i,k) = gliqwp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud liquid water path.
+            ficemr(i,k) = state%q(i,k,ixcldice) /                 &
+                 max(1.e-10_r8,(state%q(i,k,ixcldice)+state%q(i,k,ixcldliq)))
+         end do
+     end do
+     cwp(:ncol,:pver) = cicewp(:ncol,:pver) + cliqwp(:ncol,:pver)
+   else
+      if (iclwp_idx<=0 .or. iciwp_idx<=0) then 
+         call endrun('old_ice_get_rad_props_lw: oldicewp must be set to true since ICIWP and/or ICLWP were not found in pbuf')
+      endif
+      call pbuf_get_field(pbuf, iclwp_idx, iclwpth)
+      call pbuf_get_field(pbuf, iciwp_idx, iciwpth)
+      do k=1,pver
+         do i = 1,ncol
+            cwp(i,k) = 1000.0_r8 *iciwpth(i,k) + 1000.0_r8 *iclwpth(i,k)
+            ficemr(i,k) = 1000.0_r8*iciwpth(i,k)/(max(1.e-18_r8,cwp(i,k)))
+         end do
+      end do
+   endif
+
+   do k=1,pver
+       do i=1,ncol
+
+          ! Note from Andrew Conley:
+          !  Optics for RK no longer supported, This is constructed to get
+          !  close to bit for bit.  Otherwise we could simply use ice water path
+          !note that optical properties for ice valid only
+          !in range of 13 > rei > 130 micron (Ebert and Curry 92)
+          kabsi = 0.005_r8 + 1._r8/min(max(13._r8,scalefactor*rei(i,k)),130._r8)
+          kabs =  kabsi*ficemr(i,k) ! kabsl*(1._r8-ficemr(i,k)) + kabsi*ficemr(i,k)
+          cldtau(i,k) = kabs*cwp(i,k)
+       end do
+   end do
+
+   do lwband = 1,nlwbands
+      abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
+   enddo
+
+end subroutine old_ice_get_rad_props_lw
+
+!==============================================================================
+
+end module oldcloud_optics
diff --git a/src/physics/cam/phys_prop.F90 b/src/physics/cam/phys_prop.F90
index 568427e44e..6c504e8c78 100644
--- a/src/physics/cam/phys_prop.F90
+++ b/src/physics/cam/phys_prop.F90
@@ -11,7 +11,7 @@ module phys_prop
 
 use shr_kind_mod,   only: r8 => shr_kind_r8
 use spmd_utils,     only: masterproc
-use radconstants,   only: nrh, nlwbands, nswbands, idx_sw_diag
+use radconstants,   only: nlwbands, nswbands, idx_sw_diag
 use ioFileMod,      only: getfil
 use cam_pio_utils,  only: cam_pio_openfile
 use pio,            only: file_desc_t, var_desc_t, pio_get_var, pio_inq_varid, &
@@ -26,6 +26,7 @@ module phys_prop
 save
 
 integer, parameter, public :: ot_length = 32
+
 public :: &
    physprop_accum_unique_files,  &! Make a list of the unique set of files that contain properties
                                   ! This is an initialization step that must be done before calling physprop_init
@@ -105,6 +106,10 @@ module phys_prop
 ! array.
 character(len=256), allocatable :: uniquefilenames(:)
  
+! Number of evenly spaced intervals in rh used in this module and in the aer_rad_props module
+! for calculations of aerosol hygroscopic growth.
+integer, parameter, public :: nrh = 1000
+
 !================================================================================================
 contains
 !================================================================================================
@@ -1106,7 +1111,7 @@ subroutine bulk_props_init(physprop, nc_id)
 
    type(var_desc_T) :: vid
 
-   logical :: debug = .true.
+   logical :: debug = .false.
 
    character(len=*), parameter :: subname = 'bulk_props_init'
    !------------------------------------------------------------------------------------
@@ -1134,7 +1139,7 @@ subroutine bulk_props_init(physprop, nc_id)
    ierr = pio_get_var(nc_id, vid, physprop%num_to_mass_aer)
       
    ! Output select data to log file
-   if (debug .and. masterproc) then
+   if (debug .and. masterproc .and. idx_sw_diag > 0) then
       if (trim(physprop%aername) == 'SULFATE') then
          write(iulog, '(2x, a)') '_______ hygroscopic growth in visible band _______'
          call aer_optics_log_rh('SO4', physprop%sw_hygro_ext(:,idx_sw_diag), &
diff --git a/src/physics/cam/physpkg.F90 b/src/physics/cam/physpkg.F90
index c7d5b2524b..a439f84423 100644
--- a/src/physics/cam/physpkg.F90
+++ b/src/physics/cam/physpkg.F90
@@ -855,19 +855,22 @@ subroutine phys_init( phys_state, phys_tend, pbuf2d, cam_in, cam_out )
     ! low level, so init it early. Must at least do this before radiation.
     call wv_sat_init
 
+    ! solar irradiance data modules
+    call solar_data_init()
+
     ! CAM3 prescribed aerosols
     if (cam3_aero_data_on) call cam3_aero_data_init(phys_state)
 
     ! Initialize rad constituents and their properties
     call rad_cnst_init()
+
+    call radiation_init(pbuf2d)
+
     call aer_rad_props_init()
 
     ! initialize carma
     call carma_init()
 
-    ! solar irradiance data modules
-    call solar_data_init()
-
     ! Prognostic chemistry.
     call chem_init(phys_state,pbuf2d)
 
@@ -906,8 +909,6 @@ subroutine phys_init( phys_state, phys_tend, pbuf2d, cam_in, cam_out )
        endif
     endif
 
-    call radiation_init(pbuf2d)
-
     call cloud_diagnostics_init()
 
     call radheat_init(pref_mid)
diff --git a/src/physics/cam/rad_constituents.F90 b/src/physics/cam/rad_constituents.F90
index 2863197669..777af8728e 100644
--- a/src/physics/cam/rad_constituents.F90
+++ b/src/physics/cam/rad_constituents.F90
@@ -17,9 +17,9 @@ module rad_constituents
 use physics_types,  only: physics_state
 use phys_control,   only: use_simple_phys
 use constituents,   only: cnst_get_ind
-use radconstants,   only: nradgas, rad_gas_index, ot_length
+use radconstants,   only: nradgas, rad_gas_index
 use phys_prop,      only: physprop_accum_unique_files, physprop_init, &
-                          physprop_get_id
+                          physprop_get_id, ot_length
 use cam_history,    only: addfld, fieldname_len, outfld, horiz_only
 use physics_buffer, only: physics_buffer_desc, pbuf_get_field, pbuf_get_index
 
diff --git a/src/physics/rrtmg/slingo.F90 b/src/physics/cam/slingo_liq_optics.F90
similarity index 65%
rename from src/physics/rrtmg/slingo.F90
rename to src/physics/cam/slingo_liq_optics.F90
index aedb44bcee..781a056b29 100644
--- a/src/physics/rrtmg/slingo.F90
+++ b/src/physics/cam/slingo_liq_optics.F90
@@ -1,4 +1,4 @@
-module slingo
+module slingo_liq_optics
 
 !------------------------------------------------------------------------------------------------
 !  Implements Slingo Optics for MG/RRTMG for liquid clouds and
@@ -6,12 +6,12 @@ module slingo
 !------------------------------------------------------------------------------------------------
 
 use shr_kind_mod,     only: r8 => shr_kind_r8
+use physconst,        only: gravit
 use ppgrid,           only: pcols, pver, pverp
 use physics_types,    only: physics_state
 use physics_buffer,   only: physics_buffer_desc, pbuf_get_index, pbuf_get_field, pbuf_old_tim_idx
-use radconstants,     only: nswbands, nlwbands, idx_sw_diag, ot_length, idx_lw_diag, get_sw_spectral_boundaries
+use radconstants,     only: nswbands, nlwbands, get_sw_spectral_boundaries
 use cam_abortutils,   only: endrun
-use cam_history,      only: outfld
 
 implicit none
 private
@@ -19,37 +19,28 @@ module slingo
 
 public :: &
    slingo_rad_props_init,        &
-   cloud_rad_props_get_sw, & ! return SW optical props of total bulk aerosols
-   cloud_rad_props_get_lw,  & ! return LW optical props of total bulk aerosols
    slingo_liq_get_rad_props_lw, &
    slingo_liq_optics_sw
 
 ! Minimum cloud amount (as a fraction of the grid-box area) to 
 ! distinguish from clear sky
-! 
-   real(r8) cldmin
-   parameter (cldmin = 1.0e-80_r8)
-!
+real(r8), parameter :: cldmin = 1.0e-80_r8
+
 ! Decimal precision of cloud amount (0 -> preserve full resolution;
 ! 10^-n -> preserve n digits of cloud amount)
-! 
-   real(r8) cldeps
-   parameter (cldeps = 0.0_r8)
+real(r8), parameter :: cldeps = 0.0_r8
 
-! 
 ! indexes into pbuf for optical parameters of MG clouds
-! 
-   integer :: iclwp_idx  = 0 
-   integer :: iciwp_idx  = 0
-   integer :: cld_idx    = 0 
-   integer :: rel_idx  = 0
-   integer :: rei_idx  = 0
+integer :: iclwp_idx  = 0 
+integer :: iciwp_idx  = 0
+integer :: cld_idx    = 0 
+integer :: rel_idx  = 0
+integer :: rei_idx  = 0
 
 ! indexes into constituents for old optics
-   integer :: &
-        ixcldliq,   &         ! cloud liquid water index
-        ixcldice              ! cloud liquid water index
-
+integer :: &
+   ixcldliq,   &         ! cloud liquid water index
+   ixcldice              ! cloud liquid water index
 
 !==============================================================================
 contains
@@ -80,118 +71,18 @@ subroutine slingo_rad_props_init()
    call cnst_get_ind('CLDLIQ', ixcldliq)
    call cnst_get_ind('CLDICE', ixcldice)
 
-   !call addfld ('CLWPTH_OLD',(/ 'lev' /), 'I','Kg/m2','old In Cloud Liquid Water Path', sampling_seq='rad_lwsw')
-   !call addfld ('KEXT_OLD',(/ 'lev' /),'I','m^2/kg','old extinction')
-   !call addfld ('CLDOD_OLD',(/ 'lev' /),'I','1','old liquid OD')
-   !call addfld ('REL_OLD',(/ 'lev' /),'I','1','old liquid effective radius (liquid)')
-
-   !call addfld ('CLWPTH_NEW',(/ 'lev' /), 'I','Kg/m2','In Cloud Liquid Water Path', sampling_seq='rad_lwsw')
-   !call addfld ('KEXT_NEW',(/ 'lev' /),'I','m^2/kg','extinction')
-   !call addfld ('CLDOD_NEW',(/ 'lev' /),'I','1','liquid OD')
-
-   !call addfld('CIWPTH_NEW',(/ 'lev' /), 'I','Kg/m2','In Cloud Ice Water Path', sampling_seq='rad_lwsw')
-   !call addfld('CIWPTH_OLD',(/ 'lev' /), 'I','Kg/m2','In Cloud Ice Water Path (old)', sampling_seq='rad_lwsw')
-
-   return
-
 end subroutine slingo_rad_props_init
 
 !==============================================================================
 
-subroutine cloud_rad_props_get_sw(state, pbuf, &
-                                  tau, tau_w, tau_w_g, tau_w_f,&
-                                  diagnosticindex)
-
-! return totaled (across all species) layer tau, omega, g, f 
-! for all spectral interval for aerosols affecting the climate
-
-   ! Arguments
-   type(physics_state), intent(in) :: state
-   type(physics_buffer_desc), pointer :: pbuf(:)
-   integer, optional,   intent(in) :: diagnosticindex      ! index (if present) to radiation diagnostic information
-
-   real(r8), intent(out) :: tau    (nswbands,pcols,pver) ! aerosol extinction optical depth
-   real(r8), intent(out) :: tau_w  (nswbands,pcols,pver) ! aerosol single scattering albedo * tau
-   real(r8), intent(out) :: tau_w_g(nswbands,pcols,pver) ! aerosol assymetry parameter * tau * w
-   real(r8), intent(out) :: tau_w_f(nswbands,pcols,pver) ! aerosol forward scattered fraction * tau * w
-
-   ! Local variables
-
-   integer :: ncol
-   integer :: lchnk
-   integer :: k, i    ! lev and daycolumn indices
-   integer :: iswband ! sw band indices
-
-   real(r8) :: liq_tau    (nswbands,pcols,pver) ! aerosol extinction optical depth
-   real(r8) :: liq_tau_w  (nswbands,pcols,pver) ! aerosol single scattering albedo * tau
-   real(r8) :: liq_tau_w_g(nswbands,pcols,pver) ! aerosol assymetry parameter * tau * w
-   real(r8) :: liq_tau_w_f(nswbands,pcols,pver) ! aerosol forward scattered fraction * tau * w
-
-
-   !-----------------------------------------------------------------------------
-
-   ncol  = state%ncol
-   lchnk = state%lchnk
-
-   call slingo_liq_optics_sw(state, pbuf, tau, tau_w, tau_w_g, tau_w_f, oldliqwp=.true. )
-
-end subroutine cloud_rad_props_get_sw
-!==============================================================================
-
-subroutine cloud_rad_props_get_lw(state, pbuf, cld_abs_od, diagnosticindex, oldliq, oldice, oldcloud)
-
-! Purpose: Compute cloud longwave absorption optical depth
-!    cloud_rad_props_get_lw() is called by radlw() 
-
-   ! Arguments
-   type(physics_state), intent(in)  :: state
-   type(physics_buffer_desc), pointer  :: pbuf(:)
-   real(r8),            intent(out) :: cld_abs_od(nlwbands,pcols,pver) ! [fraction] absorption optical depth, per layer
-   integer, optional,   intent(in)  :: diagnosticindex
-   logical, optional,   intent(in)  :: oldliq  ! use old liquid optics
-   logical, optional,   intent(in)  :: oldice  ! use old ice optics
-   logical, optional,   intent(in)  :: oldcloud  ! use old optics for both (b4b)
-
-   ! Local variables
-
-   integer :: bnd_idx     ! LW band index
-   integer :: i           ! column index
-   integer :: k           ! lev index
-   integer :: ncol        ! number of columns
-   integer :: lchnk
-
-   ! rad properties for liquid clouds
-   real(r8) :: liq_tau_abs_od(nlwbands,pcols,pver) ! liquid cloud absorption optical depth
-
-   !-----------------------------------------------------------------------------
-
-   ncol = state%ncol
-   lchnk = state%lchnk
-
-   ! compute optical depths cld_absod 
-   cld_abs_od = 0._r8
-
-   call slingo_liq_get_rad_props_lw(state, pbuf, liq_tau_abs_od, oldliqwp=.true.)
-      
-   cld_abs_od(:,1:ncol,:) = liq_tau_abs_od(:,1:ncol,:) 
-
-end subroutine cloud_rad_props_get_lw
-
-!==============================================================================
-! Private methods
-!==============================================================================
-
-
 subroutine slingo_liq_optics_sw(state, pbuf, liq_tau, liq_tau_w, liq_tau_w_g, liq_tau_w_f, oldliqwp)
 
-   use physconst, only: gravit
-
    type(physics_state), intent(in) :: state
    type(physics_buffer_desc), pointer :: pbuf(:)
 
    real(r8),intent(out) :: liq_tau    (nswbands,pcols,pver) ! extinction optical depth
    real(r8),intent(out) :: liq_tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: liq_tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
+   real(r8),intent(out) :: liq_tau_w_g(nswbands,pcols,pver) ! asymmetry parameter * tau * w
    real(r8),intent(out) :: liq_tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
    logical, intent(in) :: oldliqwp
 
@@ -202,14 +93,6 @@ subroutine slingo_liq_optics_sw(state, pbuf, liq_tau, liq_tau_w, liq_tau_w_g, li
    real(r8), dimension(nswbands) :: wavmin
    real(r8), dimension(nswbands) :: wavmax
 
-   ! Minimum cloud amount (as a fraction of the grid-box area) to 
-   ! distinguish from clear sky
-   real(r8), parameter :: cldmin = 1.0e-80_r8
-
-   ! Decimal precision of cloud amount (0 -> preserve full resolution;
-   ! 10^-n -> preserve n digits of cloud amount)
-   real(r8), parameter :: cldeps = 0.0_r8
-
    ! A. Slingo's data for cloud particle radiative properties (from 'A GCM
    ! Parameterization for the Shortwave Properties of Water Clouds' JAS
    ! vol. 46 may 1989 pp 1419-1427)
@@ -318,16 +201,9 @@ subroutine slingo_liq_optics_sw(state, pbuf, liq_tau, liq_tau_w, liq_tau_w_g, li
       end do    ! End do k=1,pver
    end do ! nswbands
 
-   !call outfld('CL_OD_SW_OLD',liq_tau(idx_sw_diag,:,:), pcols, lchnk)
-   !call outfld('REL_OLD',rel(:,:), pcols, lchnk)
-   !call outfld('CLWPTH_OLD',cliqwp(:,:), pcols, lchnk)
-   !call outfld('KEXT_OLD',kext(:,:), pcols, lchnk)
-
-
 end subroutine slingo_liq_optics_sw
 
 subroutine slingo_liq_get_rad_props_lw(state, pbuf, abs_od, oldliqwp)
-   use physconst, only: gravit
 
    type(physics_state), intent(in)  :: state
    type(physics_buffer_desc),pointer  :: pbuf(:)
@@ -403,7 +279,6 @@ subroutine slingo_liq_get_rad_props_lw(state, pbuf, abs_od, oldliqwp)
       abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
    enddo
 
-
 end subroutine slingo_liq_get_rad_props_lw
 
-end module slingo
+end module slingo_liq_optics
diff --git a/src/physics/cam_dev/physpkg.F90 b/src/physics/cam_dev/physpkg.F90
index 1c461c9a1c..46805c150e 100644
--- a/src/physics/cam_dev/physpkg.F90
+++ b/src/physics/cam_dev/physpkg.F90
@@ -839,16 +839,19 @@ subroutine phys_init( phys_state, phys_tend, pbuf2d, cam_in, cam_out )
     ! low level, so init it early. Must at least do this before radiation.
     call wv_sat_init
 
+    ! solar irradiance data modules
+    call solar_data_init()
+
     ! Initialize rad constituents and their properties
     call rad_cnst_init()
+
+    call radiation_init(pbuf2d)
+
     call aer_rad_props_init()
 
     ! initialize carma
     call carma_init()
 
-    ! solar irradiance data modules
-    call solar_data_init()
-
     ! Prognostic chemistry.
     call chem_init(phys_state,pbuf2d)
 
@@ -884,8 +887,6 @@ subroutine phys_init( phys_state, phys_tend, pbuf2d, cam_in, cam_out )
        endif
     endif
 
-    call radiation_init(pbuf2d)
-
     call cloud_diagnostics_init()
 
     call radheat_init(pref_mid)
diff --git a/src/physics/camrt/radconstants.F90 b/src/physics/camrt/radconstants.F90
index 89503fd0f5..c95c8d2154 100644
--- a/src/physics/camrt/radconstants.F90
+++ b/src/physics/camrt/radconstants.F90
@@ -21,9 +21,6 @@ module radconstants
    public :: radconstants_init
    public :: rad_gas_index
 
-! optics files specify a type.  What length is it?
-integer, parameter, public :: ot_length = 32
-
 ! SHORTWAVE DATA
 
 ! number of shorwave spectral intervals
@@ -40,20 +37,6 @@ module radconstants
 
 integer, parameter, public :: idx_lw_diag = 2 ! index to (H20 window) LW band
 
-
-! Number of evenly spaced intervals in rh
-! The globality of this mesh may not be necessary
-! Perhaps it could be specific to the aerosol
-! But it is difficult to see how refined it must be
-! for lookup.  This value was found to be sufficient
-! for Sulfate and probably necessary to resolve the
-! high variation near rh = 1.  Alternative methods
-! were found to be too slow.
-! Optimal approach would be for cam to specify size of aerosol
-! based on each aerosol's characteristics.  Radiation 
-! should know nothing about hygroscopic growth!
-integer, parameter, public :: nrh = 1000  
-
 ! LONGWAVE DATA
 
 ! number of lw bands
diff --git a/src/physics/camrt/radiation.F90 b/src/physics/camrt/radiation.F90
index 7cd74faa11..7ca7b15daa 100644
--- a/src/physics/camrt/radiation.F90
+++ b/src/physics/camrt/radiation.F90
@@ -877,7 +877,7 @@ subroutine radiation_tend( &
    ! Aerosol shortwave radiative properties
    real(r8) :: aer_tau    (pcols,0:pver,nswbands) ! aerosol extinction optical depth
    real(r8) :: aer_tau_w  (pcols,0:pver,nswbands) ! aerosol single scattering albedo * tau
-   real(r8) :: aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol assymetry parameter * w * tau
+   real(r8) :: aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol asymmetry parameter * w * tau
    real(r8) :: aer_tau_w_f(pcols,0:pver,nswbands) ! aerosol forward scattered fraction * w * tau
 
    ! Aerosol longwave absorption optical depth
diff --git a/src/physics/camrt/radsw.F90 b/src/physics/camrt/radsw.F90
index e0d609a4cc..58138e4a5f 100644
--- a/src/physics/camrt/radsw.F90
+++ b/src/physics/camrt/radsw.F90
@@ -237,7 +237,7 @@ subroutine radcswmx(lchnk   ,ncol    ,                         &
 ! 
    real(r8),intent(in) :: E_aer_tau    (pcols,0:pver,nswbands) ! aerosol extinction optical depth
    real(r8),intent(in) :: E_aer_tau_w  (pcols,0:pver,nswbands) ! aerosol single scattering albedo * tau
-   real(r8),intent(in) :: E_aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol assymetry parameter * w * tau
+   real(r8),intent(in) :: E_aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol asymmetry parameter * w * tau
    real(r8),intent(in) :: E_aer_tau_w_f(pcols,0:pver,nswbands) ! aerosol forward scattered fraction * w * tau
 
 ! 
@@ -288,7 +288,7 @@ subroutine radcswmx(lchnk   ,ncol    ,                         &
 !
    real(r8):: aer_tau    (pcols,0:pver,nswbands) ! aerosol extinction optical depth
    real(r8):: aer_tau_w  (pcols,0:pver,nswbands) ! aerosol single scattering albedo * tau
-   real(r8):: aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol assymetry parameter * w * tau
+   real(r8):: aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol asymmetry parameter * w * tau
    real(r8):: aer_tau_w_f(pcols,0:pver,nswbands) ! aerosol forward scattered fraction * w * tau
    real(r8) :: pmid(pcols,pver) ! Level pressure
    real(r8) :: pint(pcols,pverp) ! Interface pressure
@@ -1994,7 +1994,7 @@ subroutine raddedmx(coszrs  ,ndayc   ,abh2o   , &
 !
    real(r8) trmin                ! Minimum total transmission allowed
    real(r8) wray                 ! Rayleigh single scatter albedo
-   real(r8) gray                 ! Rayleigh asymetry parameter
+   real(r8) gray                 ! Rayleigh asymmetry parameter
    real(r8) fray                 ! Rayleigh forward scattered fraction
 
    parameter (trmin = 1.e-3_r8)
diff --git a/src/physics/rrtmg/aer_src/rrtmg_sw_reftra.f90 b/src/physics/rrtmg/aer_src/rrtmg_sw_reftra.f90
index d37f392025..1622e48450 100644
--- a/src/physics/rrtmg/aer_src/rrtmg_sw_reftra.f90
+++ b/src/physics/rrtmg/aer_src/rrtmg_sw_reftra.f90
@@ -43,7 +43,7 @@ subroutine reftra_sw(nlayers, ncol, lrtchk, pgg, prmuz, ptau, pw, &
 !      lrtchk  = .t. for all layers in clear profile
 !      lrtchk  = .t. for cloudy layers in cloud profile 
 !              = .f. for clear layers in cloud profile
-!      pgg     = assymetry factor
+!      pgg     = asymmetry factor
 !      prmuz   = cosine solar zenith angle
 !      ptau    = optical thickness
 !      pw      = single scattering albedo
diff --git a/src/physics/rrtmg/oldcloud.F90 b/src/physics/rrtmg/oldcloud.F90
deleted file mode 100644
index 609c6b4668..0000000000
--- a/src/physics/rrtmg/oldcloud.F90
+++ /dev/null
@@ -1,643 +0,0 @@
-module oldcloud
-
-!------------------------------------------------------------------------------------------------
-!------------------------------------------------------------------------------------------------
-
-use shr_kind_mod,     only: r8 => shr_kind_r8
-use ppgrid,           only: pcols, pver, pverp
-use physics_types,    only: physics_state
-use physics_buffer,   only: physics_buffer_desc, pbuf_get_index, pbuf_old_tim_idx, pbuf_get_field
-use radconstants,     only: nswbands, nlwbands, idx_sw_diag, ot_length, idx_lw_diag, get_sw_spectral_boundaries
-use cam_abortutils,   only: endrun
-use cam_history,      only: outfld
-use rad_constituents, only: iceopticsfile, liqopticsfile
-use ebert_curry,      only: scalefactor
-
-implicit none
-private
-save
-
-public :: &
- oldcloud_init, oldcloud_lw, old_liq_get_rad_props_lw, old_ice_get_rad_props_lw
-
-integer :: nmu, nlambda
-real(r8), allocatable :: g_mu(:)           ! mu samples on grid
-real(r8), allocatable :: g_lambda(:,:)     ! lambda scale samples on grid
-real(r8), allocatable :: ext_sw_liq(:,:,:)
-real(r8), allocatable :: ssa_sw_liq(:,:,:)
-real(r8), allocatable :: asm_sw_liq(:,:,:)
-real(r8), allocatable :: abs_lw_liq(:,:,:)
-
-integer :: n_g_d
-real(r8), allocatable :: g_d_eff(:)        ! radiative effective diameter samples on grid
-real(r8), allocatable :: ext_sw_ice(:,:)
-real(r8), allocatable :: ssa_sw_ice(:,:)
-real(r8), allocatable :: asm_sw_ice(:,:)
-real(r8), allocatable :: abs_lw_ice(:,:)
-
-! Minimum cloud amount (as a fraction of the grid-box area) to 
-! distinguish from clear sky
-! 
-   real(r8) cldmin
-   parameter (cldmin = 1.0e-80_r8)
-!
-! Decimal precision of cloud amount (0 -> preserve full resolution;
-! 10^-n -> preserve n digits of cloud amount)
-! 
-   real(r8) cldeps
-   parameter (cldeps = 0.0_r8)
-
-! 
-! indexes into pbuf for optical parameters of MG clouds
-! 
-   integer ::   iciwp_idx   = 0 
-   integer ::   iclwp_idx   = 0 
-   integer ::   cld_idx     = 0 
-   integer ::   rel_idx     = 0 
-   integer ::   rei_idx     = 0 
-
-! indexes into constituents for old optics
-   integer :: &
-        ixcldice,           & ! cloud ice water index
-        ixcldliq              ! cloud liquid water index
-
-
-!==============================================================================
-contains
-!==============================================================================
-
-subroutine oldcloud_init()
-
-   use constituents,   only: cnst_get_ind
-
-   integer :: err
-
-   iciwp_idx  = pbuf_get_index('ICIWP',errcode=err)
-   iclwp_idx  = pbuf_get_index('ICLWP',errcode=err)
-   cld_idx    = pbuf_get_index('CLD')
-   rel_idx    = pbuf_get_index('REL')
-   rei_idx    = pbuf_get_index('REI')
-
-   ! old optics
-   call cnst_get_ind('CLDICE', ixcldice)
-   call cnst_get_ind('CLDLIQ', ixcldliq)
-
-   return
-
-end subroutine oldcloud_init
-
-!==============================================================================
-! Private methods
-!==============================================================================
-
-subroutine old_liquid_optics_sw(state, pbuf, liq_tau, liq_tau_w, liq_tau_w_g, liq_tau_w_f, oldliqwp)
-
-   use physconst, only: gravit
-
-   type(physics_state), intent(in) :: state
-   type(physics_buffer_desc),pointer :: pbuf(:)
-
-   real(r8),intent(out) :: liq_tau    (nswbands,pcols,pver) ! extinction optical depth
-   real(r8),intent(out) :: liq_tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: liq_tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
-   real(r8),intent(out) :: liq_tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
-   logical, intent(in) :: oldliqwp
-
-   real(r8), pointer, dimension(:,:) :: rel
-   real(r8), pointer, dimension(:,:) :: cldn
-   real(r8), pointer, dimension(:,:) :: tmpptr
-   real(r8), dimension(pcols,pver) :: cliqwp
-   real(r8), dimension(nswbands) :: wavmin
-   real(r8), dimension(nswbands) :: wavmax
-
-   ! Minimum cloud amount (as a fraction of the grid-box area) to 
-   ! distinguish from clear sky
-   real(r8), parameter :: cldmin = 1.0e-80_r8
-
-   ! Decimal precision of cloud amount (0 -> preserve full resolution;
-   ! 10^-n -> preserve n digits of cloud amount)
-   real(r8), parameter :: cldeps = 0.0_r8
-
-   ! A. Slingo's data for cloud particle radiative properties (from 'A GCM
-   ! Parameterization for the Shortwave Properties of Water Clouds' JAS
-   ! vol. 46 may 1989 pp 1419-1427)
-   real(r8) :: abarl(4) = &  ! A coefficient for extinction optical depth
-      (/ 2.817e-02_r8, 2.682e-02_r8,2.264e-02_r8,1.281e-02_r8/)
-   real(r8) :: bbarl(4) = &  ! B coefficient for extinction optical depth
-      (/ 1.305_r8    , 1.346_r8    ,1.454_r8    ,1.641_r8    /)
-   real(r8) :: cbarl(4) = &  ! C coefficient for single scat albedo
-      (/-5.62e-08_r8 ,-6.94e-06_r8 ,4.64e-04_r8 ,0.201_r8    /)
-   real(r8) :: dbarl(4) = &  ! D coefficient for single  scat albedo
-      (/ 1.63e-07_r8 , 2.35e-05_r8 ,1.24e-03_r8 ,7.56e-03_r8 /)
-   real(r8) :: ebarl(4) = &  ! E coefficient for asymmetry parameter
-      (/ 0.829_r8    , 0.794_r8    ,0.754_r8    ,0.826_r8    /)
-   real(r8) :: fbarl(4) = &  ! F coefficient for asymmetry parameter
-      (/ 2.482e-03_r8, 4.226e-03_r8,6.560e-03_r8,4.353e-03_r8/)
-
-   real(r8) :: abarli        ! A coefficient for current spectral band
-   real(r8) :: bbarli        ! B coefficient for current spectral band
-   real(r8) :: cbarli        ! C coefficient for current spectral band
-   real(r8) :: dbarli        ! D coefficient for current spectral band
-   real(r8) :: ebarli        ! E coefficient for current spectral band
-   real(r8) :: fbarli        ! F coefficient for current spectral band
-
-   ! Caution... A. Slingo recommends no less than 4.0 micro-meters nor
-   ! greater than 20 micro-meters
-
-   integer :: ns, i, k, indxsl, Nday
-   integer :: lchnk, itim_old
-   real(r8) :: tmp1l, tmp2l, tmp3l, g
-   real(r8) :: kext(pcols,pver)
-   real(r8), pointer, dimension(:,:) :: iclwpth
-
-   Nday = state%ncol
-   lchnk = state%lchnk
-
-   itim_old = pbuf_old_tim_idx()
-   call pbuf_get_field(pbuf, cld_idx,cldn, start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
-   call pbuf_get_field(pbuf, rel_idx,rel)
-
-   if (oldliqwp) then
-     do k=1,pver
-        do i = 1,Nday
-           cliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/(gravit*max(0.01_r8,cldn(i,k)))
-        end do
-     end do
-   else
-     if (iclwp_idx<0) then 
-        call endrun('old_liquid_optics_sw: oldliqwp must be set to true since ICLWP was not found in pbuf')
-     endif
-     ! The following is the eventual target specification for in cloud liquid water path.
-     call pbuf_get_field(pbuf, iclwp_idx, tmpptr)
-     cliqwp = tmpptr
-   endif
-  
-   call get_sw_spectral_boundaries(wavmin,wavmax,'microns')
-
-   do ns = 1, nswbands
-      ! Set index for cloud particle properties based on the wavelength,
-      ! according to A. Slingo (1989) equations 1-3:
-      ! Use index 1 (0.25 to 0.69 micrometers) for visible
-      ! Use index 2 (0.69 - 1.19 micrometers) for near-infrared
-      ! Use index 3 (1.19 to 2.38 micrometers) for near-infrared
-      ! Use index 4 (2.38 to 4.00 micrometers) for near-infrared
-      if(wavmax(ns) <= 0.7_r8) then
-         indxsl = 1
-      else if(wavmax(ns) <= 1.25_r8) then
-         indxsl = 2
-      else if(wavmax(ns) <= 2.38_r8) then
-         indxsl = 3
-      else if(wavmin(ns) > 2.38_r8) then
-         indxsl = 4
-      end if
-
-      ! Set cloud extinction optical depth, single scatter albedo,
-      ! asymmetry parameter, and forward scattered fraction:
-      abarli = abarl(indxsl)
-      bbarli = bbarl(indxsl)
-      cbarli = cbarl(indxsl)
-      dbarli = dbarl(indxsl)
-      ebarli = ebarl(indxsl)
-      fbarli = fbarl(indxsl)
-
-      do k=1,pver
-         do i=1,Nday
-
-            ! note that optical properties for liquid valid only
-            ! in range of 4.2 > rel > 16 micron (Slingo 89)
-            if (cldn(i,k) >= cldmin .and. cldn(i,k) >= cldeps) then
-               tmp1l = abarli + bbarli/min(max(4.2_r8,rel(i,k)),16._r8)
-               liq_tau(ns,i,k) = 1000._r8*cliqwp(i,k)*tmp1l
-            else
-               liq_tau(ns,i,k) = 0.0_r8
-            endif
-
-            tmp2l = 1._r8 - cbarli - dbarli*min(max(4.2_r8,rel(i,k)),16._r8)
-            tmp3l = fbarli*min(max(4.2_r8,rel(i,k)),16._r8)
-            ! Do not let single scatter albedo be 1.  Delta-eddington solution
-            ! for non-conservative case has different analytic form from solution
-            ! for conservative case, and raddedmx is written for non-conservative case.
-            liq_tau_w(ns,i,k) = liq_tau(ns,i,k) * min(tmp2l,.999999_r8)
-            g = ebarli + tmp3l
-            liq_tau_w_g(ns,i,k) = liq_tau_w(ns,i,k) * g
-            liq_tau_w_f(ns,i,k) = liq_tau_w(ns,i,k) * g * g
-
-         end do ! End do i=1,Nday
-      end do    ! End do k=1,pver
-   end do ! nswbands
-
-   !call outfld('CL_OD_SW_OLD',liq_tau(idx_sw_diag,:,:), pcols, lchnk)
-   !call outfld('REL_OLD',rel(:,:), pcols, lchnk)
-   !call outfld('CLWPTH_OLD',cliqwp(:,:), pcols, lchnk)
-   !call outfld('KEXT_OLD',kext(:,:), pcols, lchnk)
-
-
-end subroutine old_liquid_optics_sw
-!==============================================================================
-
-subroutine old_ice_optics_sw   (state, pbuf, ice_tau, ice_tau_w, ice_tau_w_g, ice_tau_w_f, oldicewp)
-
-   use physconst, only: gravit
-
-   type(physics_state), intent(in) :: state
-   type(physics_buffer_desc),pointer :: pbuf(:)
-
-   real(r8),intent(out) :: ice_tau    (nswbands,pcols,pver) ! extinction optical depth
-   real(r8),intent(out) :: ice_tau_w  (nswbands,pcols,pver) ! single scattering albedo * tau
-   real(r8),intent(out) :: ice_tau_w_g(nswbands,pcols,pver) ! assymetry parameter * tau * w
-   real(r8),intent(out) :: ice_tau_w_f(nswbands,pcols,pver) ! forward scattered fraction * tau * w
-   logical, intent(in) :: oldicewp
-
-   real(r8), pointer, dimension(:,:) :: rei
-   real(r8), pointer, dimension(:,:) :: cldn
-   real(r8), pointer, dimension(:,:) :: tmpptr
-   real(r8), dimension(pcols,pver) :: cicewp
-   real(r8), dimension(nswbands) :: wavmin
-   real(r8), dimension(nswbands) :: wavmax
-   !
-   ! ice water coefficients (Ebert and Curry,1992, JGR, 97, 3831-3836)
-   real(r8) :: abari(4) = &     ! a coefficient for extinction optical depth
-      (/ 3.448e-03_r8, 3.448e-03_r8,3.448e-03_r8,3.448e-03_r8/)
-   real(r8) :: bbari(4) = &     ! b coefficient for extinction optical depth
-      (/ 2.431_r8    , 2.431_r8    ,2.431_r8    ,2.431_r8    /)
-   real(r8) :: cbari(4) = &     ! c coefficient for single scat albedo
-      (/ 1.00e-05_r8 , 1.10e-04_r8 ,1.861e-02_r8,.46658_r8   /)
-   real(r8) :: dbari(4) = &     ! d coefficient for single scat albedo
-      (/ 0.0_r8      , 1.405e-05_r8,8.328e-04_r8,2.05e-05_r8 /)
-   real(r8) :: ebari(4) = &     ! e coefficient for asymmetry parameter
-      (/ 0.7661_r8   , 0.7730_r8   ,0.794_r8    ,0.9595_r8   /)
-   real(r8) :: fbari(4) = &     ! f coefficient for asymmetry parameter
-      (/ 5.851e-04_r8, 5.665e-04_r8,7.267e-04_r8,1.076e-04_r8/)
-
-   real(r8) :: abarii           ! A coefficient for current spectral band
-   real(r8) :: bbarii           ! B coefficient for current spectral band
-   real(r8) :: cbarii           ! C coefficient for current spectral band
-   real(r8) :: dbarii           ! D coefficient for current spectral band
-   real(r8) :: ebarii           ! E coefficient for current spectral band
-   real(r8) :: fbarii           ! F coefficient for current spectral band
-
-   ! Minimum cloud amount (as a fraction of the grid-box area) to 
-   ! distinguish from clear sky
-   real(r8), parameter :: cldmin = 1.0e-80_r8
-
-   ! Decimal precision of cloud amount (0 -> preserve full resolution;
-   ! 10^-n -> preserve n digits of cloud amount)
-   real(r8), parameter :: cldeps = 0.0_r8
-
-   integer :: ns, i, k, indxsl, lchnk, Nday
-   integer :: itim_old
-   real(r8) :: tmp1i, tmp2i, tmp3i, g
-
-   Nday = state%ncol
-   lchnk = state%lchnk
-
-   itim_old = pbuf_old_tim_idx()
-   call pbuf_get_field(pbuf, cld_idx,cldn, start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
-   call pbuf_get_field(pbuf, rei_idx,rei)
-
-   if(oldicewp) then
-     do k=1,pver
-        do i = 1,Nday
-           cicewp(i,k) = 1000.0_r8*state%q(i,k,ixcldice)*state%pdel(i,k) /(gravit* max(0.01_r8,cldn(i,k)))
-        end do
-     end do
-   else
-     if (iciwp_idx<=0) then
-        call endrun('old_ice_optics_sw: oldicewp must be set to true since ICIWP was not found in pbuf')
-     endif
-     call pbuf_get_field(pbuf, iciwp_idx, tmpptr)
-     cicewp(1:pcols,1:pver) =  1000.0_r8*tmpptr
-   endif
-   
-   call get_sw_spectral_boundaries(wavmin,wavmax,'microns')
-
-   do ns = 1, nswbands
-
-      if(wavmax(ns) <= 0.7_r8) then
-         indxsl = 1
-      else if(wavmax(ns) <= 1.25_r8) then
-         indxsl = 2
-      else if(wavmax(ns) <= 2.38_r8) then
-         indxsl = 3
-      else if(wavmin(ns) > 2.38_r8) then
-         indxsl = 4
-      end if
-
-      abarii = abari(indxsl)
-      bbarii = bbari(indxsl)
-      cbarii = cbari(indxsl)
-      dbarii = dbari(indxsl)
-      ebarii = ebari(indxsl)
-      fbarii = fbari(indxsl)
-
-      do k=1,pver
-         do i=1,Nday
-
-            ! note that optical properties for ice valid only
-            ! in range of 13 > rei > 130 micron (Ebert and Curry 92)
-            if (cldn(i,k) >= cldmin .and. cldn(i,k) >= cldeps) then
-               tmp1i = abarii + bbarii/max(13._r8,min(scalefactor*rei(i,k),130._r8))
-               ice_tau(ns,i,k) = cicewp(i,k)*tmp1i
-            else
-               ice_tau(ns,i,k) = 0.0_r8
-            endif
-
-            tmp2i = 1._r8 - cbarii - dbarii*min(max(13._r8,scalefactor*rei(i,k)),130._r8)
-            tmp3i = fbarii*min(max(13._r8,scalefactor*rei(i,k)),130._r8)
-            ! Do not let single scatter albedo be 1.  Delta-eddington solution
-            ! for non-conservative case has different analytic form from solution
-            ! for conservative case, and raddedmx is written for non-conservative case.
-            ice_tau_w(ns,i,k) = ice_tau(ns,i,k) * min(tmp2i,.999999_r8)
-            g = ebarii + tmp3i
-            ice_tau_w_g(ns,i,k) = ice_tau_w(ns,i,k) * g
-            ice_tau_w_f(ns,i,k) = ice_tau_w(ns,i,k) * g * g
-
-         end do ! End do i=1,Nday
-      end do    ! End do k=1,pver
-   end do ! nswbands
-
-end subroutine old_ice_optics_sw
-!==============================================================================
-
-subroutine oldcloud_lw(state,pbuf,cld_abs_od,oldwp)
-   use physconst, only: gravit
-   type(physics_state), intent(in) :: state
-   type(physics_buffer_desc),pointer :: pbuf(:)
-   real(r8),            intent(out) :: cld_abs_od(nlwbands,pcols,pver) ! [fraction] absorption optical depth, per layer
-   logical,intent(in)              :: oldwp ! use old definition of waterpath
-
-
-   real(r8) :: gicewp(pcols,pver)
-   real(r8) :: gliqwp(pcols,pver)
-   real(r8) :: cicewp(pcols,pver)
-   real(r8) :: cliqwp(pcols,pver)
-   real(r8) :: ficemr(pcols,pver)
-   real(r8) :: cwp(pcols,pver)
-   real(r8) :: cldtau(pcols,pver)
-
-   real(r8), pointer, dimension(:,:) :: cldn
-   real(r8), pointer, dimension(:,:) :: rei 
-   integer :: ncol, itim_old, lwband, i, k, lchnk
-   real(r8), pointer, dimension(:,:) :: iclwpth, iciwpth
-
-    real(r8) :: kabs, kabsi
-    real(r8) kabsl                  ! longwave liquid absorption coeff (m**2/g)
-    parameter (kabsl = 0.090361_r8)
-
-
- 
-   ncol = state%ncol
-   lchnk = state%lchnk
-
-   itim_old  =  pbuf_old_tim_idx()
-   call pbuf_get_field(pbuf, rei_idx,   rei)
-   call pbuf_get_field(pbuf, cld_idx,   cldn,   start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
-
-   if (oldwp) then
-     do k=1,pver
-         do i = 1,ncol
-            gicewp(i,k) = state%q(i,k,ixcldice)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box ice water path.
-            gliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box liquid water path.
-            cicewp(i,k) = gicewp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud ice water path.
-            cliqwp(i,k) = gliqwp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud liquid water path.
-            ficemr(i,k) = state%q(i,k,ixcldice) /                 &
-                 max(1.e-10_r8,(state%q(i,k,ixcldice)+state%q(i,k,ixcldliq)))
-         end do
-     end do
-     cwp(:ncol,:pver) = cicewp(:ncol,:pver) + cliqwp(:ncol,:pver)
-   else
-      if (iclwp_idx<=0 .or. iciwp_idx<=0) then 
-         call endrun('oldcloud_lw: oldwp must be set to true since ICIWP and/or ICLWP were not found in pbuf')
-      endif
-      call pbuf_get_field(pbuf, iclwp_idx, iclwpth)
-      call pbuf_get_field(pbuf, iciwp_idx, iciwpth)
-      do k=1,pver
-         do i = 1,ncol
-            cwp(i,k) = 1000.0_r8 *iclwpth(i,k) + 1000.0_r8 *iciwpth(i, k)
-            ficemr(i,k) = 1000.0_r8 * iciwpth(i,k)/(max(1.e-18_r8,cwp(i,k)))
-         end do
-      end do
-   endif
-
-   do k=1,pver
-       do i=1,ncol
-
-          !note that optical properties for ice valid only
-          !in range of 13 > rei > 130 micron (Ebert and Curry 92)
-          kabsi = 0.005_r8 + 1._r8/min(max(13._r8,scalefactor*rei(i,k)),130._r8)
-          kabs = kabsl*(1._r8-ficemr(i,k)) + kabsi*ficemr(i,k)
-          !emis(i,k) = 1._r8 - exp(-1.66_r8*kabs*clwp(i,k))
-          cldtau(i,k) = kabs*cwp(i,k)
-       end do
-   end do
-!
-   do lwband = 1,nlwbands
-      cld_abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
-   enddo
-
-end subroutine oldcloud_lw
-
-!==============================================================================
-subroutine old_liq_get_rad_props_lw(state, pbuf, abs_od, oldliqwp)
-   use physconst, only: gravit
-
-   type(physics_state), intent(in)  :: state
-   type(physics_buffer_desc),pointer  :: pbuf(:)
-   real(r8), intent(out) :: abs_od(nlwbands,pcols,pver)
-   logical, intent(in) :: oldliqwp
-
-   real(r8) :: gicewp(pcols,pver)
-   real(r8) :: gliqwp(pcols,pver)
-   real(r8) :: cicewp(pcols,pver)
-   real(r8) :: cliqwp(pcols,pver)
-   real(r8) :: ficemr(pcols,pver)
-   real(r8) :: cwp(pcols,pver)
-   real(r8) :: cldtau(pcols,pver)
-   
-   real(r8), pointer, dimension(:,:) :: cldn
-   real(r8), pointer, dimension(:,:) :: rei
-   integer :: ncol, itim_old, lwband, i, k, lchnk 
-
-   real(r8) :: kabs, kabsi
-   real(r8) kabsl                  ! longwave liquid absorption coeff (m**2/g)
-   parameter (kabsl = 0.090361_r8)
-
-   real(r8), pointer, dimension(:,:) :: iclwpth, iciwpth
-
-   ncol=state%ncol
-   lchnk = state%lchnk
-
-   itim_old  =  pbuf_old_tim_idx()
-   call pbuf_get_field(pbuf, rei_idx,   rei)
-   call pbuf_get_field(pbuf, cld_idx,   cldn,   start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
-
-   if (oldliqwp) then
-     do k=1,pver
-         do i = 1,ncol
-            gicewp(i,k) = state%q(i,k,ixcldice)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box ice water path.
-            gliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box liquid water path.
-            cicewp(i,k) = gicewp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud ice water path.
-            cliqwp(i,k) = gliqwp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud liquid water path.
-            ficemr(i,k) = state%q(i,k,ixcldice) /                 &
-                 max(1.e-10_r8,(state%q(i,k,ixcldice)+state%q(i,k,ixcldliq)))
-         end do
-     end do
-     cwp(:ncol,:pver) = cicewp(:ncol,:pver) + cliqwp(:ncol,:pver)
-   else
-      if (iclwp_idx<=0 .or. iciwp_idx<=0) then 
-         call endrun('old_liq_get_rad_props_lw: oldliqwp must be set to true since ICIWP and/or ICLWP were not found in pbuf')
-      endif
-      call pbuf_get_field(pbuf, iclwp_idx, iclwpth)
-      call pbuf_get_field(pbuf, iciwp_idx, iciwpth)
-      do k=1,pver
-         do i = 1,ncol
-            cwp(i,k) = 1000.0_r8 *iclwpth(i,k) + 1000.0_r8 *iciwpth(i, k)
-            ficemr(i,k) = 1000.0_r8 * iciwpth(i,k)/(max(1.e-18_r8,cwp(i,k)))
-         end do
-      end do
-   endif
-
-
-   do k=1,pver
-       do i=1,ncol
-
-          ! Note from Andrew Conley:
-          !  Optics for RK no longer supported, This is constructed to get
-          !  close to bit for bit.  Otherwise we could simply use liquid water path
-          !note that optical properties for ice valid only
-          !in range of 13 > rei > 130 micron (Ebert and Curry 92)
-          kabsi = 0.005_r8 + 1._r8/min(max(13._r8,scalefactor*rei(i,k)),130._r8)
-          kabs = kabsl*(1._r8-ficemr(i,k)) ! + kabsi*ficemr(i,k)
-          !emis(i,k) = 1._r8 - exp(-1.66_r8*kabs*clwp(i,k))
-          cldtau(i,k) = kabs*cwp(i,k)
-       end do
-   end do
-!
-   do lwband = 1,nlwbands
-      abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
-   enddo
-
-
-end subroutine old_liq_get_rad_props_lw
-!==============================================================================
-
-subroutine old_ice_get_rad_props_lw(state, pbuf, abs_od, oldicewp)
-   use physconst, only: gravit
-   type(physics_state), intent(in)  :: state
-   type(physics_buffer_desc),pointer  :: pbuf(:)
-    real(r8), intent(out) :: abs_od(nlwbands,pcols,pver)
-   logical, intent(in) :: oldicewp
-
-   real(r8) :: gicewp(pcols,pver)
-   real(r8) :: gliqwp(pcols,pver)
-   real(r8) :: cicewp(pcols,pver)
-   real(r8) :: cliqwp(pcols,pver)
-   real(r8) :: ficemr(pcols,pver)
-   real(r8) :: cwp(pcols,pver)
-   real(r8) :: cldtau(pcols,pver)
-
-   real(r8), pointer, dimension(:,:) :: cldn
-   real(r8), pointer, dimension(:,:) :: rei
-   integer :: ncol, itim_old, lwband, i, k, lchnk
-
-    real(r8) :: kabs, kabsi
-
-    real(r8) kabsl                  ! longwave liquid absorption coeff (m**2/g)
-    parameter (kabsl = 0.090361_r8)
-
-   real(r8), pointer, dimension(:,:) :: iclwpth, iciwpth
-
-
-   ncol = state%ncol
-   lchnk = state%lchnk
-
-   itim_old  =  pbuf_old_tim_idx()
-   call pbuf_get_field(pbuf, rei_idx,   rei)
-   call pbuf_get_field(pbuf, cld_idx,   cldn,   start=(/1,1,itim_old/), kount=(/pcols,pver,1/))
-
-   if(oldicewp) then
-     do k=1,pver
-         do i = 1,ncol
-            gicewp(i,k) = state%q(i,k,ixcldice)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box ice water path.
-            gliqwp(i,k) = state%q(i,k,ixcldliq)*state%pdel(i,k)/gravit*1000.0_r8  ! Grid box liquid water path.
-            cicewp(i,k) = gicewp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud ice water path.
-            cliqwp(i,k) = gliqwp(i,k) / max(0.01_r8,cldn(i,k))                 ! In-cloud liquid water path.
-            ficemr(i,k) = state%q(i,k,ixcldice) /                 &
-                 max(1.e-10_r8,(state%q(i,k,ixcldice)+state%q(i,k,ixcldliq)))
-         end do
-     end do
-     cwp(:ncol,:pver) = cicewp(:ncol,:pver) + cliqwp(:ncol,:pver)
-   else
-      if (iclwp_idx<=0 .or. iciwp_idx<=0) then 
-         call endrun('old_ice_get_rad_props_lw: oldicewp must be set to true since ICIWP and/or ICLWP were not found in pbuf')
-      endif
-      call pbuf_get_field(pbuf, iclwp_idx, iclwpth)
-      call pbuf_get_field(pbuf, iciwp_idx, iciwpth)
-      do k=1,pver
-         do i = 1,ncol
-            cwp(i,k) = 1000.0_r8 *iciwpth(i,k) + 1000.0_r8 *iclwpth(i,k)
-            ficemr(i,k) = 1000.0_r8*iciwpth(i,k)/(max(1.e-18_r8,cwp(i,k)))
-         end do
-      end do
-   endif
-
-   do k=1,pver
-       do i=1,ncol
-
-          ! Note from Andrew Conley:
-          !  Optics for RK no longer supported, This is constructed to get
-          !  close to bit for bit.  Otherwise we could simply use ice water path
-          !note that optical properties for ice valid only
-          !in range of 13 > rei > 130 micron (Ebert and Curry 92)
-          kabsi = 0.005_r8 + 1._r8/min(max(13._r8,scalefactor*rei(i,k)),130._r8)
-          kabs =  kabsi*ficemr(i,k) ! kabsl*(1._r8-ficemr(i,k)) + kabsi*ficemr(i,k)
-          !emis(i,k) = 1._r8 - exp(-1.66_r8*kabs*clwp(i,k))
-          cldtau(i,k) = kabs*cwp(i,k)
-       end do
-   end do
-!
-   do lwband = 1,nlwbands
-      abs_od(lwband,1:ncol,1:pver)=cldtau(1:ncol,1:pver)
-   enddo
-
-   !if(oldicewp) then
-   !  call outfld('CIWPTH_OLD',cicewp(:,:)/1000,pcols,lchnk)
-   !else
-   !  call outfld('CIWPTH_OLD',iciwpth(:,:),pcols,lchnk)
-   !endif
-   !call outfld('CI_OD_LW_OLD',cldtau(:,:),pcols,lchnk)
-
-end subroutine old_ice_get_rad_props_lw
-!==============================================================================
-
-subroutine cloud_total_vis_diag_out(lchnk, nnite, idxnite, tau, radsuffix)
-
-   ! output total aerosol optical depth for the visible band
-
-   use cam_history, only: outfld
-   use cam_history_support, only : fillvalue
-
-   integer,          intent(in) :: lchnk
-   integer,          intent(in) :: nnite          ! number of night columns
-   integer,          intent(in) :: idxnite(nnite) ! local column indices of night columns
-   real(r8),         intent(in) :: tau(:,:)
-   character(len=*), intent(in) :: radsuffix ! identifies whether the radiation call
-                                             ! is for the climate calc or a diagnostic calc
- 
-   ! Local variables
-   integer  :: i
-   real(r8) :: tmp(pcols)
-   !-----------------------------------------------------------------------------
-
-   ! compute total aerosol optical depth output where only daylight columns
-   tmp(:) = sum(tau(:,:), 2)
-   do i = 1, nnite
-      tmp(idxnite(i)) = fillvalue
-   end do
-   !call outfld('cloudOD_v'//trim(radsuffix), tmp, pcols, lchnk)
-
-end subroutine cloud_total_vis_diag_out
-
-!==============================================================================
-
-end module oldcloud
diff --git a/src/physics/rrtmg/radconstants.F90 b/src/physics/rrtmg/radconstants.F90
index f4f8c76b9c..601bcd3cf6 100644
--- a/src/physics/rrtmg/radconstants.F90
+++ b/src/physics/rrtmg/radconstants.F90
@@ -63,19 +63,6 @@ module radconstants
 
 integer, parameter, public :: rrtmg_sw_cloudsim_band = 9  ! rrtmg band for .67 micron
 
-! Number of evenly spaced intervals in rh
-! The globality of this mesh may not be necessary
-! Perhaps it could be specific to the aerosol
-! But it is difficult to see how refined it must be
-! for lookup.  This value was found to be sufficient
-! for Sulfate and probably necessary to resolve the
-! high variation near rh = 1.  Alternative methods
-! were found to be too slow.
-! Optimal approach would be for cam to specify size of aerosol
-! based on each aerosol's characteristics.  Radiation 
-! should know nothing about hygroscopic growth!
-integer, parameter, public :: nrh = 1000  
-
 ! LONGWAVE DATA
 
 ! These are indices to the band for diagnostic output
@@ -123,9 +110,6 @@ module radconstants
 real(r8), public, parameter :: minmmr(nradgas) &
    = epsilon(1._r8)
 
-! Length of "optics type" string specified in optics files.
-integer, parameter, public :: ot_length = 32
-
 public :: rad_gas_index
 
 public :: get_number_sw_bands, &
diff --git a/src/physics/rrtmg/radiation.F90 b/src/physics/rrtmg/radiation.F90
index 4ca347d749..12f8cd7ec6 100644
--- a/src/physics/rrtmg/radiation.F90
+++ b/src/physics/rrtmg/radiation.F90
@@ -728,8 +728,8 @@ subroutine radiation_tend( &
                                  ice_cloud_get_rad_props_lw, cloud_rad_props_get_lw, &
                                  grau_cloud_get_rad_props_lw, get_grau_optics_sw, &
                                  snow_cloud_get_rad_props_lw, get_snow_optics_sw
-   use slingo,             only: slingo_liq_get_rad_props_lw, slingo_liq_optics_sw
-   use ebert_curry,        only: ec_ice_optics_sw, ec_ice_get_rad_props_lw
+   use slingo_liq_optics,  only: slingo_liq_get_rad_props_lw, slingo_liq_optics_sw
+   use ebert_curry_ice_optics, only: ec_ice_optics_sw, ec_ice_get_rad_props_lw
 
    use rad_solar_var,      only: get_variability
    use radsw,              only: rad_rrtmg_sw
@@ -806,28 +806,28 @@ subroutine radiation_tend( &
    ! cloud radiative parameters are "in cloud" not "in cell"
    real(r8) :: ice_tau    (nswbands,pcols,pver) ! ice extinction optical depth
    real(r8) :: ice_tau_w  (nswbands,pcols,pver) ! ice single scattering albedo * tau
-   real(r8) :: ice_tau_w_g(nswbands,pcols,pver) ! ice assymetry parameter * tau * w
+   real(r8) :: ice_tau_w_g(nswbands,pcols,pver) ! ice asymmetry parameter * tau * w
    real(r8) :: ice_tau_w_f(nswbands,pcols,pver) ! ice forward scattered fraction * tau * w
    real(r8) :: ice_lw_abs (nlwbands,pcols,pver)   ! ice absorption optics depth (LW)
 
    ! cloud radiative parameters are "in cloud" not "in cell"
    real(r8) :: liq_tau    (nswbands,pcols,pver) ! liquid extinction optical depth
    real(r8) :: liq_tau_w  (nswbands,pcols,pver) ! liquid single scattering albedo * tau
-   real(r8) :: liq_tau_w_g(nswbands,pcols,pver) ! liquid assymetry parameter * tau * w
+   real(r8) :: liq_tau_w_g(nswbands,pcols,pver) ! liquid asymmetry parameter * tau * w
    real(r8) :: liq_tau_w_f(nswbands,pcols,pver) ! liquid forward scattered fraction * tau * w
    real(r8) :: liq_lw_abs (nlwbands,pcols,pver) ! liquid absorption optics depth (LW)
 
    ! cloud radiative parameters are "in cloud" not "in cell"
    real(r8) :: cld_tau    (nswbands,pcols,pver) ! cloud extinction optical depth
    real(r8) :: cld_tau_w  (nswbands,pcols,pver) ! cloud single scattering albedo * tau
-   real(r8) :: cld_tau_w_g(nswbands,pcols,pver) ! cloud assymetry parameter * w * tau
+   real(r8) :: cld_tau_w_g(nswbands,pcols,pver) ! cloud asymmetry parameter * w * tau
    real(r8) :: cld_tau_w_f(nswbands,pcols,pver) ! cloud forward scattered fraction * w * tau
    real(r8) :: cld_lw_abs (nlwbands,pcols,pver) ! cloud absorption optics depth (LW)
 
    ! cloud radiative parameters are "in cloud" not "in cell"
    real(r8) :: snow_tau    (nswbands,pcols,pver) ! snow extinction optical depth
    real(r8) :: snow_tau_w  (nswbands,pcols,pver) ! snow single scattering albedo * tau
-   real(r8) :: snow_tau_w_g(nswbands,pcols,pver) ! snow assymetry parameter * tau * w
+   real(r8) :: snow_tau_w_g(nswbands,pcols,pver) ! snow asymmetry parameter * tau * w
    real(r8) :: snow_tau_w_f(nswbands,pcols,pver) ! snow forward scattered fraction * tau * w
    real(r8) :: snow_lw_abs (nlwbands,pcols,pver)! snow absorption optics depth (LW)
 
@@ -835,7 +835,7 @@ subroutine radiation_tend( &
    ! cloud radiative parameters are "in cloud" not "in cell"
    real(r8) :: grau_tau    (nswbands,pcols,pver) ! graupel extinction optical depth
    real(r8) :: grau_tau_w  (nswbands,pcols,pver) ! graupel single scattering albedo * tau
-   real(r8) :: grau_tau_w_g(nswbands,pcols,pver) ! graupel assymetry parameter * tau * w
+   real(r8) :: grau_tau_w_g(nswbands,pcols,pver) ! graupel asymmetry parameter * tau * w
    real(r8) :: grau_tau_w_f(nswbands,pcols,pver) ! graupel forward scattered fraction * tau * w
    real(r8) :: grau_lw_abs (nlwbands,pcols,pver)! graupel absorption optics depth (LW)
 
@@ -843,7 +843,7 @@ subroutine radiation_tend( &
    real(r8) :: cldfprime(pcols,pver)              ! combined cloud fraction (snow plus regular)
    real(r8) :: c_cld_tau    (nswbands,pcols,pver) ! combined cloud extinction optical depth
    real(r8) :: c_cld_tau_w  (nswbands,pcols,pver) ! combined cloud single scattering albedo * tau
-   real(r8) :: c_cld_tau_w_g(nswbands,pcols,pver) ! combined cloud assymetry parameter * w * tau
+   real(r8) :: c_cld_tau_w_g(nswbands,pcols,pver) ! combined cloud asymmetry parameter * w * tau
    real(r8) :: c_cld_tau_w_f(nswbands,pcols,pver) ! combined cloud forward scattered fraction * w * tau
    real(r8) :: c_cld_lw_abs (nlwbands,pcols,pver) ! combined cloud absorption optics depth (LW)
 
@@ -855,7 +855,7 @@ subroutine radiation_tend( &
    ! Aerosol radiative properties
    real(r8) :: aer_tau    (pcols,0:pver,nswbands) ! aerosol extinction optical depth
    real(r8) :: aer_tau_w  (pcols,0:pver,nswbands) ! aerosol single scattering albedo * tau
-   real(r8) :: aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol assymetry parameter * w * tau
+   real(r8) :: aer_tau_w_g(pcols,0:pver,nswbands) ! aerosol asymmetry parameter * w * tau
    real(r8) :: aer_tau_w_f(pcols,0:pver,nswbands) ! aerosol forward scattered fraction * w * tau
    real(r8) :: aer_lw_abs (pcols,pver,nlwbands)   ! aerosol absorption optics depth (LW)
 
diff --git a/src/physics/rrtmg/radsw.F90 b/src/physics/rrtmg/radsw.F90
index df222557dd..994d56b44e 100644
--- a/src/physics/rrtmg/radsw.F90
+++ b/src/physics/rrtmg/radsw.F90
@@ -255,7 +255,7 @@ subroutine rad_rrtmg_sw(lchnk,ncol       ,rrtmg_levs   ,r_state      , &
    ! Aerosol radiative property arrays
    real(r8) :: tauxar(pcols,0:pver) ! aerosol extinction optical depth
    real(r8) :: wa(pcols,0:pver) ! aerosol single scattering albedo
-   real(r8) :: ga(pcols,0:pver) ! aerosol assymetry parameter
+   real(r8) :: ga(pcols,0:pver) ! aerosol asymmetry parameter
    real(r8) :: fa(pcols,0:pver) ! aerosol forward scattered fraction
 
    ! CRM
diff --git a/src/physics/rrtmgp/mcica_subcol_gen.F90 b/src/physics/rrtmgp/mcica_subcol_gen.F90
new file mode 100644
index 0000000000..85bea8281c
--- /dev/null
+++ b/src/physics/rrtmgp/mcica_subcol_gen.F90
@@ -0,0 +1,286 @@
+module mcica_subcol_gen
+
+!----------------------------------------------------------------------------------------
+! 
+! Purpose: Create McICA stochastic arrays for cloud optical properties.
+! Input cloud optical properties directly: cloud optical depth, single
+! scattering albedo and asymmetry parameter.  Output will be stochastic
+! arrays of these variables.  (longwave scattering is not yet available)
+!
+! Original code: From RRTMG, with the following copyright notice,
+! based on Raisanen et al., QJRMS, 2004:
+!  --------------------------------------------------------------------------
+! |                                                                          |
+! |  Copyright 2006-2007, Atmospheric & Environmental Research, Inc. (AER).  |
+! |  This software may be used, copied, or redistributed as long as it is    |
+! |  not sold and this copyright notice is reproduced on each copy made.     |
+! |  This model is provided as is without any express or implied warranties. |
+! |                       (http://www.rtweb.aer.com/)                        |
+! |                                                                          |
+!  --------------------------------------------------------------------------
+! This code is a refactored version of code originally in the files
+! mcica_subcol_gen_lw.F90 and mcica_subcol_gen_sw.F90
+! 
+! Uses the KISS random number generator.
+!
+! Overlap assumption: maximum-random.
+! 
+!----------------------------------------------------------------------------------------
+
+use shr_kind_mod,         only: r8 => shr_kind_r8
+use ppgrid,               only: pcols, pver
+use shr_RandNum_mod,      only: ShrKissRandGen
+use mo_gas_optics_rrtmgp, only: ty_gas_optics_rrtmgp
+
+implicit none
+private
+save
+
+public :: mcica_subcol_lw, mcica_subcol_sw
+
+!========================================================================================
+contains
+!========================================================================================
+
+subroutine mcica_subcol_lw( &
+   kdist, nbnd, ngpt, ncol, nver,           &
+   changeseed, pmid, cldfrac, tauc, taucmcl )
+
+   ! Arrays use CAM vertical index convention: index increases from top to bottom.
+   ! This index ordering is assumed in the maximum-random overlap algorithm which starts
+   ! at the top of a column and marches down, with each layer depending on the state
+   ! of the layer above it.
+   !
+   ! For GCM mode, changeseed must be offset between LW and SW by at least the
+   ! number of subcolumns
+
+   ! arguments
+   class(ty_gas_optics_rrtmgp), intent(in) :: kdist  ! spectral information
+   integer,  intent(in)  :: nbnd                     ! number of spectral bands
+   integer,  intent(in)  :: ngpt                     ! number of subcolumns (g-point intervals)
+   integer,  intent(in)  :: ncol                     ! number of columns
+   integer,  intent(in)  :: nver                     ! number of layers
+   integer,  intent(in)  :: changeseed               ! if the subcolumn generator is called multiple times, 
+                                                     ! permute the seed between each call.
+   real(r8), intent(in)  :: pmid(pcols,pver)         ! layer pressures (Pa)
+   real(r8), intent(in)  :: cldfrac(ncol,nver)       ! layer cloud fraction
+   real(r8), intent(in)  :: tauc(nbnd,ncol,nver)     ! cloud optical depth
+   real(r8), intent(out) :: taucmcl(ngpt,ncol,nver)  ! subcolumn cloud optical depth [mcica]
+
+   ! Local variables
+
+   integer :: i, isubcol, k, n
+
+   real(r8), parameter :: cldmin = 1.0e-80_r8  ! min cloud fraction
+   real(r8) :: cldf(ncol,pver)      ! cloud fraction clipped to cldmin
+
+   type(ShrKissRandGen) :: kiss_gen  ! KISS RNG object
+   integer  :: kiss_seed(ncol,4)
+   real(r8) :: rand_num_1d(ncol,1)   ! random number (kissvec)
+   real(r8) :: rand_num(ncol,nver)   ! random number (kissvec)
+
+   real(r8) :: cdf(ngpt,ncol,nver)   ! random numbers
+   logical  :: iscloudy(ngpt,ncol,nver)   ! flag that says whether a gridbox is cloudy
+   !------------------------------------------------------------------------------------------ 
+
+   ! clip cloud fraction
+   cldf(:,:) = cldfrac(:ncol,:)
+   where (cldf(:,:) < cldmin)
+      cldf(:,:) = 0._r8
+   end where
+
+   ! Create a seed that depends on the state of the columns.
+   ! Use pmid from bottom four layers. 
+   do i = 1, ncol
+      kiss_seed(i,1) = (pmid(i,pver)   - int(pmid(i,pver)))    * 1000000000
+      kiss_seed(i,2) = (pmid(i,pver-1) - int(pmid(i,pver-1)))  * 1000000000
+      kiss_seed(i,3) = (pmid(i,pver-2) - int(pmid(i,pver-2)))  * 1000000000
+      kiss_seed(i,4) = (pmid(i,pver-3) - int(pmid(i,pver-3)))  * 1000000000
+   end do
+
+   ! create the RNG object
+   kiss_gen = ShrKissRandGen(kiss_seed)
+
+   ! Advance randum number generator by changeseed values
+   do i = 1, changeSeed
+      call kiss_gen%random(rand_num_1d)
+   end do
+
+   ! Generate random numbers in each subcolumn at every level
+   do isubcol = 1,ngpt
+      call kiss_gen%random(rand_num)
+      cdf(isubcol,:,:) = rand_num(:,:)
+   enddo
+
+   ! Maximum-Random overlap
+   ! i) pick a random number for top layer.
+   ! ii) walk down the column: 
+   !    - if the layer above is cloudy, use the same random number as in the layer above
+   !    - if the layer above is clear, use a new random number 
+
+   do k = 2, nver
+      do i = 1, ncol
+         do isubcol = 1, ngpt
+            if (cdf(isubcol,i,k-1) > 1._r8 - cldf(i,k-1) ) then
+               cdf(isubcol,i,k) = cdf(isubcol,i,k-1) 
+            else
+               cdf(isubcol,i,k) = cdf(isubcol,i,k) * (1._r8 - cldf(i,k-1))
+            end if
+         end do
+      end do
+   end do
+ 
+   do k = 1, nver
+      iscloudy(:,:,k) = (cdf(:,:,k) >= 1._r8 - spread(cldf(:,k), dim=1, nCopies=ngpt) )
+   end do
+
+   ! -- generate subcolumns for homogeneous clouds -----
+   ! where there is a cloud, set the subcolumn cloud properties;
+   ! incoming tauc should be in-cloud quantites and not grid-averaged quantities
+   do k = 1,nver
+      do i = 1,ncol
+         do isubcol = 1,ngpt
+            if (iscloudy(isubcol,i,k) .and. (cldf(i,k) > 0._r8) ) then
+               n = kdist%convert_gpt2band(isubcol)
+               taucmcl(isubcol,i,k) = tauc(n,i,k)
+            else
+               taucmcl(isubcol,i,k) = 0._r8
+            end if
+         end do
+      end do
+   end do
+
+   call kiss_gen%finalize()
+
+end subroutine mcica_subcol_lw
+
+!========================================================================================
+
+subroutine mcica_subcol_sw( &
+   kdist, nbnd, ngpt, ncol, nlay, nver, changeseed, &
+   pmid, cldfrac, tauc, ssac, asmc,     &
+   taucmcl, ssacmcl, asmcmcl)
+
+   ! Arrays use CAM vertical index convention: index increases from top to bottom.
+   ! This index ordering is assumed in the maximum-random overlap algorithm which starts
+   ! at the top of a column and marches down, with each layer depending on the state
+   ! of the layer above it.
+   !
+   ! For GCM mode, changeseed must be offset between LW and SW by at least the
+   ! number of subcolumns
+
+   ! arguments
+   class(ty_gas_optics_rrtmgp), intent(in) :: kdist  ! spectral information
+   integer,  intent(in)  :: nbnd                    ! number of spectral bands
+   integer,  intent(in)  :: ngpt                    ! number of subcolumns (g-point intervals)
+   integer,  intent(in)  :: ncol                    ! number of columns
+   integer,  intent(in)  :: nlay                    ! number of vertical layers in radiation calc;
+                                                    !   may include an "extra layer"
+   integer,  intent(in)  :: nver                    ! number of CAM's vertical layers in rad calc
+   integer,  intent(in)  :: changeseed              ! if the subcolumn generator is called multiple times, 
+                                                    ! permute the seed between each call.
+   real(r8), intent(in)  :: pmid(ncol,nlay)         ! layer midpoint pressures (Pa)
+   real(r8), intent(in)  :: cldfrac(ncol,nver)      ! layer cloud fraction
+   real(r8), intent(in)  :: tauc(nbnd,ncol,nver)    ! cloud optical depth
+   real(r8), intent(in)  :: ssac(nbnd,ncol,nver)    ! cloud single scattering albedo (non-delta scaled)
+   real(r8), intent(in)  :: asmc(nbnd,ncol,nver)    ! cloud asymmetry parameter (non-delta scaled)
+
+
+   real(r8), intent(out) :: taucmcl(ngpt,ncol,nver) ! subcolumn cloud optical depth [mcica]
+   real(r8), intent(out) :: ssacmcl(ngpt,ncol,nver) ! subcolumn cloud single scattering albedo [mcica]
+   real(r8), intent(out) :: asmcmcl(ngpt,ncol,nver) ! subcolumn cloud asymmetry parameter [mcica]
+
+   ! Local vars
+
+   integer :: i, isubcol, k, n
+
+   real(r8), parameter :: cldmin = 1.0e-80_r8  ! min cloud fraction
+   real(r8) :: cldf(ncol,nver)      ! cloud fraction clipped to cldmin
+
+   type(ShrKissRandGen) :: kiss_gen  ! KISS RNG object
+   integer  :: kiss_seed(ncol,4)
+   real(r8) :: rand_num_1d(ncol,1)   ! random number (kissvec)
+   real(r8) :: rand_num(ncol,nver)   ! random number (kissvec)
+
+   real(r8) :: cdf(ngpt,ncol,nver)   ! random numbers
+   logical  :: iscloudy(ngpt,ncol,nver)   ! flag that says whether a gridbox is cloudy
+   !------------------------------------------------------------------------------------------ 
+
+   ! clip cloud fraction
+   cldf(:,:) = cldfrac(:ncol,:)
+   where (cldf(:,:) < cldmin)
+      cldf(:,:) = 0._r8
+   end where
+
+   ! Create a seed that depends on the state of the columns.
+   ! Use pmid from bottom four layers. 
+   do i = 1, ncol
+      kiss_seed(i,1) = (pmid(i,nlay)   - int(pmid(i,nlay)))    * 1000000000
+      kiss_seed(i,2) = (pmid(i,nlay-1) - int(pmid(i,nlay-1)))  * 1000000000
+      kiss_seed(i,3) = (pmid(i,nlay-2) - int(pmid(i,nlay-2)))  * 1000000000
+      kiss_seed(i,4) = (pmid(i,nlay-3) - int(pmid(i,nlay-3)))  * 1000000000
+   end do
+
+   ! create the RNG object
+   kiss_gen = ShrKissRandGen(kiss_seed)
+
+   ! Advance randum number generator by changeseed values
+   do i = 1, changeSeed
+      call kiss_gen%random(rand_num_1d)
+   end do
+
+   ! Generate random numbers in each subcolumn at every level
+   do isubcol = 1,ngpt
+      call kiss_gen%random(rand_num)
+      cdf(isubcol,:,:) = rand_num(:,:)
+   enddo
+
+   ! Maximum-Random overlap
+   ! i) pick a random number for top layer.
+   ! ii) walk down the column: 
+   !    - if the layer above is cloudy, use the same random number as in the layer above
+   !    - if the layer above is clear, use a new random number 
+
+   do k = 2, nver
+      do i = 1, ncol
+         do isubcol = 1, ngpt
+            if (cdf(isubcol,i,k-1) > 1._r8 - cldf(i,k-1) ) then
+               cdf(isubcol,i,k) = cdf(isubcol,i,k-1) 
+            else
+               cdf(isubcol,i,k) = cdf(isubcol,i,k) * (1._r8 - cldf(i,k-1))
+            end if
+         end do
+      end do
+   end do
+ 
+   do k = 1, nver
+      iscloudy(:,:,k) = (cdf(:,:,k) >= 1._r8 - spread(cldf(:,k), dim=1, nCopies=ngpt) )
+   end do
+
+   ! -- generate subcolumns for homogeneous clouds -----
+   ! where there is a cloud, set the subcolumn cloud properties;
+   ! incoming tauc should be in-cloud quantites and not grid-averaged quantities
+   do k = 1,nver
+      do i = 1,ncol
+         do isubcol = 1,ngpt
+            if (iscloudy(isubcol,i,k) .and. (cldf(i,k) > 0._r8) ) then
+               n = kdist%convert_gpt2band(isubcol)
+               taucmcl(isubcol,i,k) = tauc(n,i,k)
+               ssacmcl(isubcol,i,k) = ssac(n,i,k)
+               asmcmcl(isubcol,i,k) = asmc(n,i,k)
+            else
+               taucmcl(isubcol,i,k) = 0._r8
+               ssacmcl(isubcol,i,k) = 1._r8
+               asmcmcl(isubcol,i,k) = 0._r8
+            end if
+         end do
+      end do
+   end do
+
+   call kiss_gen%finalize()
+
+end subroutine mcica_subcol_sw
+
+
+end module mcica_subcol_gen
+
diff --git a/src/physics/rrtmgp/radconstants.F90 b/src/physics/rrtmgp/radconstants.F90
new file mode 100644
index 0000000000..f490b81b7b
--- /dev/null
+++ b/src/physics/rrtmgp/radconstants.F90
@@ -0,0 +1,295 @@
+module radconstants
+
+! This module contains constants that are specific to the radiative transfer
+! code used in the RRTMGP model.
+
+use shr_kind_mod,         only: r8 => shr_kind_r8
+use mo_gas_optics_rrtmgp, only: ty_gas_optics_rrtmgp
+use cam_abortutils,       only: endrun
+
+implicit none
+private
+save
+
+! Number of bands in SW and LW.  These values must match data in the RRTMGP coefficients datasets.
+! But they are needed to allocate space in the physics buffer and need to be available before the
+! RRTMGP datasets are read.  So they are set as parameters here and checked in the 
+! set_wavenumber_bands subroutine after the datasets are read.
+integer, parameter, public :: nswbands = 14
+integer, parameter, public :: nlwbands = 16
+
+! Band limits (set from data in RRTMGP coefficient datasets)
+real(r8), target :: wavenumber_low_shortwave(nswbands)
+real(r8), target :: wavenumber_high_shortwave(nswbands)
+real(r8), target :: wavenumber_low_longwave(nlwbands)
+real(r8), target :: wavenumber_high_longwave(nlwbands)
+
+logical :: wavenumber_boundaries_set = .false.
+
+integer, public, protected :: nswgpts  ! number of SW g-points
+integer, public, protected :: nlwgpts  ! number of LW g-points
+
+! These are indices to specific bands for diagnostic output and COSP input.
+integer, public, protected :: idx_sw_diag = -1     ! band contains 500-nm wave
+integer, public, protected :: idx_nir_diag = -1    ! band contains 1000-nm wave
+integer, public, protected :: idx_uv_diag = -1     ! band contains 400-nm wave
+integer, public, protected :: idx_lw_diag = -1     ! band contains 1000 cm-1 wave (H20 window)
+integer, public, protected :: idx_sw_cloudsim = -1 ! band contains 670-nm wave (for COSP)
+integer, public, protected :: idx_lw_cloudsim = -1 ! band contains 10.5 micron wave (for COSP)
+
+! GASES TREATED BY RADIATION (line spectra)
+! These names are recognized by RRTMGP.  They are in the coefficients files as
+! lower case strings.  These upper case names are used by CAM's namelist and 
+! rad_constituents module.
+integer, public, parameter :: gasnamelength = 5
+integer, public, parameter :: nradgas = 8
+character(len=gasnamelength), public, parameter :: gaslist(nradgas) &
+   = (/'H2O  ','O3   ', 'O2   ', 'CO2  ', 'N2O  ', 'CH4  ', 'CFC11', 'CFC12'/)
+
+! what is the minimum mass mixing ratio that can be supported by radiation implementation?
+real(r8), public, parameter :: minmmr(nradgas) = epsilon(1._r8)
+
+public :: &
+   set_wavenumber_bands,       &
+   get_sw_spectral_boundaries, &
+   get_lw_spectral_boundaries, &
+   get_band_index_by_value,    &
+   rad_gas_index
+
+!=========================================================================================
+contains
+!=========================================================================================
+
+subroutine set_wavenumber_bands(kdist_sw, kdist_lw)
+
+   ! Set the low and high limits of the wavenumber grid for sw and lw.
+   ! Values come from RRTMGP coefficients datasets, and are stored in the
+   ! kdist objects.
+   !
+   ! Set band indices for bands containing specific wavelengths.
+
+   ! Arguments
+   type(ty_gas_optics_rrtmgp), intent(in) :: kdist_sw
+   type(ty_gas_optics_rrtmgp), intent(in) :: kdist_lw
+
+   ! Local variables
+   integer :: istat
+   real(r8), allocatable :: values(:,:)
+
+   character(len=128) :: errmsg
+   character(len=*), parameter :: sub = 'set_wavenumber_bands'
+   !----------------------------------------------------------------------------
+
+   ! Check that number of sw/lw bands in gas optics files matches the parameters.
+   if (kdist_sw%get_nband() /= nswbands) then
+      write(errmsg,'(a,i4,a,i4)') 'number of sw bands in file, ', kdist_sw%get_nband(), &
+         ", doesn't match parameter nswbands= ", nswbands
+      call endrun(sub//': ERROR: '//trim(errmsg))
+   end if
+   if (kdist_lw%get_nband() /= nlwbands) then
+      write(errmsg,'(a,i4,a,i4)') 'number of lw bands in file, ', kdist_lw%get_nband(), &
+         ", doesn't match parameter nlwbands= ", nlwbands
+      call endrun(sub//': ERROR: '//trim(errmsg))
+   end if
+
+   nswgpts = kdist_sw%get_ngpt()
+   nlwgpts = kdist_lw%get_ngpt()
+
+   ! SW band bounds in cm^-1
+   allocate( values(2,nswbands), stat=istat )
+   if (istat/=0) then
+      call endrun(sub//': ERROR allocating array: values(2,nswbands)')
+   end if
+   values = kdist_sw%get_band_lims_wavenumber()
+   wavenumber_low_shortwave = values(1,:)
+   wavenumber_high_shortwave = values(2,:)
+
+   ! Indices into specific bands
+   idx_sw_diag     = get_band_index_by_value('sw', 500.0_r8, 'nm')
+   idx_nir_diag    = get_band_index_by_value('sw', 1000.0_r8, 'nm')
+   idx_uv_diag     = get_band_index_by_value('sw', 400._r8, 'nm')
+   idx_sw_cloudsim = get_band_index_by_value('sw', 0.67_r8, 'micron')
+
+   deallocate(values)
+
+   ! LW band bounds in cm^-1
+   allocate( values(2,nlwbands), stat=istat )
+   if (istat/=0) then
+      call endrun(sub//': ERROR allocating array: values(2,nlwbands)')
+   end if
+   values = kdist_lw%get_band_lims_wavenumber()
+   wavenumber_low_longwave = values(1,:)
+   wavenumber_high_longwave = values(2,:)
+
+   ! Indices into specific bands
+   idx_lw_diag     = get_band_index_by_value('lw', 1000.0_r8, 'cm^-1')
+   idx_lw_cloudsim = get_band_index_by_value('lw', 10.5_r8, 'micron')
+
+   wavenumber_boundaries_set = .true.
+
+end subroutine set_wavenumber_bands
+
+!=========================================================================================
+
+subroutine get_sw_spectral_boundaries(low_boundaries, high_boundaries, units)
+
+   ! provide spectral boundaries of each shortwave band
+
+   real(r8),    intent(out) :: low_boundaries(nswbands), high_boundaries(nswbands)
+   character(*), intent(in) :: units ! requested units
+
+   character(len=*), parameter :: sub = 'get_sw_spectral_boundaries'
+   !----------------------------------------------------------------------------
+
+   if (.not. wavenumber_boundaries_set) then
+      call endrun(sub//': ERROR, wavenumber boundaries not set. ')
+   end if
+
+   select case (units)
+   case ('inv_cm','cm^-1','cm-1')
+      low_boundaries = wavenumber_low_shortwave
+      high_boundaries = wavenumber_high_shortwave
+   case('m','meter','meters')
+      low_boundaries = 1.e-2_r8/wavenumber_high_shortwave
+      high_boundaries = 1.e-2_r8/wavenumber_low_shortwave
+   case('nm','nanometer','nanometers')
+      low_boundaries = 1.e7_r8/wavenumber_high_shortwave
+      high_boundaries = 1.e7_r8/wavenumber_low_shortwave
+   case('um','micrometer','micrometers','micron','microns')
+      low_boundaries = 1.e4_r8/wavenumber_high_shortwave
+      high_boundaries = 1.e4_r8/wavenumber_low_shortwave
+   case('cm','centimeter','centimeters')
+      low_boundaries  = 1._r8/wavenumber_high_shortwave
+      high_boundaries = 1._r8/wavenumber_low_shortwave
+   case default
+      call endrun(sub//': ERROR, requested spectral units not recognized: '//units)
+   end select
+
+end subroutine get_sw_spectral_boundaries
+
+!=========================================================================================
+
+subroutine get_lw_spectral_boundaries(low_boundaries, high_boundaries, units)
+
+   ! provide spectral boundaries of each longwave band
+
+   real(r8), intent(out) :: low_boundaries(nlwbands), high_boundaries(nlwbands)
+   character(*), intent(in) :: units ! requested units
+
+   character(len=*), parameter :: sub = 'get_lw_spectral_boundaries'
+   !----------------------------------------------------------------------------
+
+   if (.not. wavenumber_boundaries_set) then
+      call endrun(sub//': ERROR, wavenumber boundaries not set. ')
+   end if
+
+   select case (units)
+   case ('inv_cm','cm^-1','cm-1')
+      low_boundaries  = wavenumber_low_longwave
+      high_boundaries = wavenumber_high_longwave
+   case('m','meter','meters')
+      low_boundaries  = 1.e-2_r8/wavenumber_high_longwave
+      high_boundaries = 1.e-2_r8/wavenumber_low_longwave
+   case('nm','nanometer','nanometers')
+      low_boundaries  = 1.e7_r8/wavenumber_high_longwave
+      high_boundaries = 1.e7_r8/wavenumber_low_longwave
+   case('um','micrometer','micrometers','micron','microns')
+      low_boundaries  = 1.e4_r8/wavenumber_high_longwave
+      high_boundaries = 1.e4_r8/wavenumber_low_longwave
+   case('cm','centimeter','centimeters')
+      low_boundaries  = 1._r8/wavenumber_high_longwave
+      high_boundaries = 1._r8/wavenumber_low_longwave
+   case default
+      call endrun(sub//': ERROR, requested spectral units not recognized: '//units)
+   end select
+
+end subroutine get_lw_spectral_boundaries
+
+!=========================================================================================
+
+integer function rad_gas_index(gasname)
+
+   ! return the index in the gaslist array of the specified gasname
+
+   character(len=*),intent(in) :: gasname
+   integer :: igas
+
+   rad_gas_index = -1
+   do igas = 1, nradgas
+      if (trim(gaslist(igas)).eq.trim(gasname)) then
+         rad_gas_index = igas
+         return
+      endif
+   enddo
+   call endrun ("rad_gas_index: can not find gas with name "//gasname)
+end function rad_gas_index
+
+!=========================================================================================
+
+function get_band_index_by_value(swlw, targetvalue, units) result(ans)
+
+   ! Find band index for requested wavelength/wavenumber.
+
+   character(len=*), intent(in) :: swlw        ! sw or lw bands
+   real(r8),         intent(in) :: targetvalue  
+   character(len=*), intent(in) :: units       ! units of targetvalue
+   integer :: ans
+
+   ! local
+   real(r8), pointer, dimension(:) :: lowboundaries, highboundaries
+   real(r8) :: tgt
+   integer  :: nbnds, i
+
+   character(len=128) :: errmsg
+   character(len=*), parameter :: sub = 'get_band_index_by_value'
+   !----------------------------------------------------------------------------
+
+   select case (swlw)
+   case ('sw','SW','shortwave')
+      nbnds = nswbands
+      lowboundaries  => wavenumber_low_shortwave
+      highboundaries => wavenumber_high_shortwave
+   case ('lw', 'LW', 'longwave')
+      nbnds = nlwbands
+      lowboundaries  => wavenumber_low_longwave
+      highboundaries => wavenumber_high_longwave
+   case default
+      call endrun('radconstants.F90: get_band_index_by_value: type of bands not recognized: '//swlw)
+   end select
+
+   ! band info is in cm^-1 but target value may be other units,
+   ! so convert targetvalue to cm^-1
+   select case (units)
+   case ('inv_cm','cm^-1','cm-1')
+      tgt = targetvalue
+   case('m','meter','meters')
+      tgt = 1.0_r8 / (targetvalue * 1.e2_r8)
+   case('nm','nanometer','nanometers')
+      tgt = 1.0_r8 / (targetvalue * 1.e-7_r8)
+   case('um','micrometer','micrometers','micron','microns')
+      tgt = 1.0_r8 / (targetvalue * 1.e-4_r8)
+   case('cm','centimeter','centimeters')
+      tgt = 1._r8/targetvalue
+   case default
+      call endrun('radconstants.F90: get_band_index_by_value: units not recognized: '//units)
+   end select
+
+   ! now just loop through the array
+   ans = 0
+   do i = 1,nbnds
+      if ((tgt > lowboundaries(i)) .and. (tgt <= highboundaries(i))) then
+         ans = i
+         exit
+      end if
+   end do
+
+   if (ans == 0) then
+      write(errmsg,'(f10.3,a,a)') targetvalue, ' ', trim(units)
+      call endrun(sub//': band not found containing wave: '//trim(errmsg))
+   end if
+   
+end function get_band_index_by_value
+
+!=========================================================================================
+
+end module radconstants
diff --git a/src/physics/rrtmgp/radiation.F90 b/src/physics/rrtmgp/radiation.F90
new file mode 100644
index 0000000000..18488bedb7
--- /dev/null
+++ b/src/physics/rrtmgp/radiation.F90
@@ -0,0 +1,2491 @@
+module radiation
+
+!---------------------------------------------------------------------------------
+!
+! CAM interface to RRTMGP radiation parameterization.
+!
+!---------------------------------------------------------------------------------
+
+use shr_kind_mod,        only: r8=>shr_kind_r8, cl=>shr_kind_cl
+use spmd_utils,          only: masterproc
+use ppgrid,              only: pcols, pver, pverp, begchunk, endchunk
+use ref_pres,            only: pref_edge
+use physics_types,       only: physics_state, physics_ptend
+use phys_control,        only: phys_getopts
+use physics_buffer,      only: physics_buffer_desc, pbuf_add_field, dtype_r8, pbuf_get_index, &
+                               pbuf_set_field, pbuf_get_field, pbuf_old_tim_idx
+use camsrfexch,          only: cam_out_t, cam_in_t
+use physconst,           only: cappa, cpair, gravit
+use solar_irrad_data,    only: sol_tsi
+
+use time_manager,        only: get_nstep, is_first_step, is_first_restart_step, &
+                               get_curr_calday, get_step_size
+
+use rad_constituents,    only: N_DIAG, rad_cnst_get_call_list, rad_cnst_get_gas, rad_cnst_out
+
+use rrtmgp_inputs,       only: rrtmgp_inputs_init
+
+use radconstants,        only: nradgas, gasnamelength, gaslist, nswbands, nlwbands, &
+                               nswgpts, set_wavenumber_bands
+
+use cloud_rad_props,     only: cloud_rad_props_init
+
+use cospsimulator_intr,  only: docosp, cospsimulator_intr_init, &
+                               cospsimulator_intr_run, cosp_nradsteps
+
+use scamMod,             only: scm_crm_mode, single_column, have_cld, cldobs
+
+use cam_history,         only: addfld, add_default, horiz_only, outfld, hist_fld_active
+
+use radiation_data,      only: rad_data_register, rad_data_init
+
+use ioFileMod,           only: getfil
+use cam_pio_utils,       only: cam_pio_openfile
+use pio,                 only: file_desc_t, var_desc_t,                       &
+                               pio_int, pio_double, PIO_NOERR,                &
+                               pio_seterrorhandling, PIO_BCAST_ERROR,         &
+                               pio_inq_dimlen, pio_inq_dimid, pio_inq_varid,  &
+                               pio_def_var, pio_put_var, pio_get_var,         &
+                               pio_put_att, PIO_NOWRITE, pio_closefile
+
+use mo_gas_concentrations, only: ty_gas_concs
+use mo_gas_optics_rrtmgp,  only: ty_gas_optics_rrtmgp
+use mo_optical_props,      only: ty_optical_props_1scl, ty_optical_props_2str
+use mo_source_functions,   only: ty_source_func_lw
+use mo_fluxes,             only: ty_fluxes_broadband
+use mo_fluxes_byband,      only: ty_fluxes_byband
+
+use string_utils,        only: to_lower
+use cam_abortutils,      only: endrun, handle_allocate_error
+use cam_logfile,         only: iulog
+
+
+implicit none
+private
+save
+
+public :: &
+   radiation_readnl,         &! read namelist variables
+   radiation_register,       &! registers radiation physics buffer fields
+   radiation_do,             &! query which radiation calcs are done this timestep
+   radiation_init,           &! initialization
+   radiation_define_restart, &! define variables for restart
+   radiation_write_restart,  &! write variables to restart
+   radiation_read_restart,   &! read variables from restart
+   radiation_tend,           &! compute heating rates and fluxes
+   rad_out_t                  ! type for diagnostic outputs
+
+integer,public, allocatable :: cosp_cnt(:)       ! counter for cosp
+integer,public              :: cosp_cnt_init = 0 !initial value for cosp counter
+
+real(r8), public, protected :: nextsw_cday       ! future radiation calday for surface models
+
+type rad_out_t
+   real(r8) :: solin(pcols)         ! Solar incident flux
+
+   real(r8) :: qrsc(pcols,pver)
+
+   real(r8) :: fsnsc(pcols)         ! Clear sky surface abs solar flux
+   real(r8) :: fsntc(pcols)         ! Clear sky total column abs solar flux
+   real(r8) :: fsdsc(pcols)         ! Clear sky surface downwelling solar flux
+   
+   real(r8) :: fsntoa(pcols)        ! Net solar flux at TOA
+   real(r8) :: fsntoac(pcols)       ! Clear sky net solar flux at TOA
+   real(r8) :: fsutoa(pcols)        ! upwelling solar flux at TOA
+
+   real(r8) :: fsnirt(pcols)        ! Near-IR flux absorbed at toa
+   real(r8) :: fsnrtc(pcols)        ! Clear sky near-IR flux absorbed at toa
+   real(r8) :: fsnirtsq(pcols)      ! Near-IR flux absorbed at toa >= 0.7 microns
+
+   real(r8) :: fsn200(pcols)        ! Net SW flux interpolated to 200 mb
+   real(r8) :: fsn200c(pcols)       ! Net clear-sky SW flux interpolated to 200 mb
+   real(r8) :: fsnr(pcols)          ! Net SW flux interpolated to tropopause
+   
+   real(r8) :: flux_sw_up(pcols,pverp)     ! upward shortwave flux on interfaces
+   real(r8) :: flux_sw_clr_up(pcols,pverp) ! upward shortwave clearsky flux
+   real(r8) :: flux_sw_dn(pcols,pverp)     ! downward flux
+   real(r8) :: flux_sw_clr_dn(pcols,pverp) ! downward clearsky flux
+
+   real(r8) :: flux_lw_up(pcols,pverp)     ! upward longwave flux on interfaces
+   real(r8) :: flux_lw_clr_up(pcols,pverp) ! upward longwave clearsky flux
+   real(r8) :: flux_lw_dn(pcols,pverp)     ! downward flux
+   real(r8) :: flux_lw_clr_dn(pcols,pverp) ! downward clearsky flux
+
+   real(r8) :: qrlc(pcols,pver)
+
+   real(r8) :: flntc(pcols)         ! Clear sky lw flux at model top
+   real(r8) :: flut(pcols)          ! Upward flux at top of model
+   real(r8) :: flutc(pcols)         ! Upward Clear Sky flux at top of model
+   real(r8) :: lwcf(pcols)          ! longwave cloud forcing
+
+   real(r8) :: fln200(pcols)        ! net longwave flux interpolated to 200 mb
+   real(r8) :: fln200c(pcols)       ! net clearsky longwave flux interpolated to 200 mb
+   real(r8) :: flnr(pcols)          ! net longwave flux interpolated to tropopause
+
+   real(r8) :: flnsc(pcols)         ! Clear sky lw flux at srf (up-down)
+   real(r8) :: fldsc(pcols)         ! Clear sky lw flux at srf (down)
+
+   real(r8) :: tot_cld_vistau(pcols,pver)   ! gbx water+ice cloud optical depth (only during day, night = fillvalue)
+   real(r8) :: tot_icld_vistau(pcols,pver)  ! in-cld water+ice cloud optical depth (only during day, night = fillvalue)
+   real(r8) :: liq_icld_vistau(pcols,pver)  ! in-cld liq cloud optical depth (only during day, night = fillvalue)
+   real(r8) :: ice_icld_vistau(pcols,pver)  ! in-cld ice cloud optical depth (only during day, night = fillvalue)
+   real(r8) :: snow_icld_vistau(pcols,pver) ! snow in-cloud visible sw optical depth for output on history files
+   real(r8) :: grau_icld_vistau(pcols,pver) ! Graupel in-cloud visible sw optical depth for output on history files
+end type rad_out_t
+
+! Control variables set via namelist
+character(len=cl) :: coefs_lw_file ! filepath for lw coefficients
+character(len=cl) :: coefs_sw_file ! filepath for sw coefficients
+
+integer :: iradsw = -1     ! freq. of shortwave radiation calc in time steps (positive)
+                           ! or hours (negative).
+integer :: iradlw = -1     ! frequency of longwave rad. calc. in time steps (positive)
+                           ! or hours (negative).
+
+integer :: irad_always = 0 ! Specifies length of time in timesteps (positive)
+                           ! or hours (negative) SW/LW radiation will be
+                           ! run continuously from the start of an
+                           ! initial or restart run
+logical :: use_rad_dt_cosz  = .false. ! if true, use radiation dt for all cosz calculations
+logical :: spectralflux     = .false. ! calculate fluxes (up and down) per band.
+logical :: graupel_in_rad   = .false. ! graupel in radiation code
+logical :: use_rad_uniform_angle = .false. ! if true, use the namelist rad_uniform_angle for the coszrs calculation
+
+! active_calls is set by a rad_constituents method after parsing namelist input
+! for the rad_climate and rad_diag_N entries.
+logical :: active_calls(0:N_DIAG)
+
+! Physics buffer indices
+integer :: qrs_idx      = 0 
+integer :: qrl_idx      = 0 
+integer :: su_idx       = 0 
+integer :: sd_idx       = 0 
+integer :: lu_idx       = 0 
+integer :: ld_idx       = 0 
+integer :: fsds_idx     = 0
+integer :: fsns_idx     = 0
+integer :: fsnt_idx     = 0
+integer :: flns_idx     = 0
+integer :: flnt_idx     = 0
+integer :: cld_idx      = 0 
+integer :: cldfsnow_idx = 0 
+integer :: cldfgrau_idx = 0    
+
+character(len=4) :: diag(0:N_DIAG) =(/'    ','_d1 ','_d2 ','_d3 ','_d4 ','_d5 ',&
+                                      '_d6 ','_d7 ','_d8 ','_d9 ','_d10'/)
+
+! averaging time interval for zenith angle
+real(r8) :: dt_avg = 0._r8
+real(r8) :: rad_uniform_angle = -99._r8
+
+! Number of layers in radiation calculations.
+integer :: nlay
+
+! Number of CAM layers in radiation calculations.  Is either equal to nlay, or is
+! 1 less than nlay if "extra layer" is used in the radiation calculations.
+integer :: nlaycam
+
+! Indices for copying data between CAM/WACCM and RRTMGP arrays.  Since RRTMGP is
+! vertical order agnostic we can send data using the top to bottom order used
+! in CAM/WACCM.  But the number of layers that RRTMGP does computations for
+! may not match the number of layers in CAM/WACCM for two reasons:
+! 1. If the CAM model top is below 1 Pa, then RRTMGP does calculations for an
+!    extra layer that is added between 1 Pa and the model top.
+! 2. If the WACCM model top is above 1 Pa, then RRMTGP only does calculations
+!    for those model layers that are below 1 Pa.
+integer :: ktopcam ! Index in CAM arrays of top level (layer or interface) at which
+                   ! RRTMGP is active.
+integer :: ktoprad ! Index in RRTMGP arrays of the layer or interface corresponding
+                   ! to CAM's top layer or interface.
+                   ! Note: for CAM's top to bottom indexing, the index of a given layer
+                   ! (midpoint) and the upper interface of that layer, are the same.
+
+! Gas optics objects contain the data read from the coefficients files.
+type(ty_gas_optics_rrtmgp) :: kdist_sw
+type(ty_gas_optics_rrtmgp) :: kdist_lw
+
+! lower case version of gaslist for RRTMGP
+character(len=gasnamelength) :: gaslist_lc(nradgas)
+
+type(var_desc_t) :: cospcnt_desc  ! cosp
+type(var_desc_t) :: nextsw_cday_desc
+
+!=========================================================================================
+contains
+!=========================================================================================
+
+subroutine radiation_readnl(nlfile)
+
+   ! Read radiation_nl namelist group.
+
+   use namelist_utils,  only: find_group_name
+   use spmd_utils,      only: mpicom, mstrid=>masterprocid, mpi_integer, mpi_logical, &
+                              mpi_character, mpi_real8
+
+   character(len=*), intent(in) :: nlfile  ! filepath for file containing namelist input
+
+   ! Local variables
+   integer :: unitn, ierr
+   integer :: dtime      ! timestep size
+   character(len=32) :: errmsg
+   character(len=*), parameter :: sub = 'radiation_readnl'
+
+   character(len=cl) :: rrtmgp_coefs_lw_file, rrtmgp_coefs_sw_file
+
+   namelist /radiation_nl/ &
+      rrtmgp_coefs_lw_file, rrtmgp_coefs_sw_file, iradsw, iradlw,        &
+      irad_always, use_rad_dt_cosz, spectralflux, use_rad_uniform_angle, &
+      rad_uniform_angle, graupel_in_rad
+   !-----------------------------------------------------------------------------
+
+   if (masterproc) then
+      open( newunit=unitn, file=trim(nlfile), status='old' )
+      call find_group_name(unitn, 'radiation_nl', status=ierr)
+      if (ierr == 0) then
+         read(unitn, radiation_nl, iostat=ierr)
+         if (ierr /= 0) then
+            write(errmsg,'(a,i5)') 'iostat =', ierr
+            call endrun(sub//': ERROR reading namelist: '//trim(errmsg))
+         end if
+      end if
+      close(unitn)
+   end if
+
+   ! Broadcast namelist variables
+   call mpi_bcast(rrtmgp_coefs_lw_file, cl, mpi_character, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: rrtmgp_coefs_lw_file")
+   call mpi_bcast(rrtmgp_coefs_sw_file, cl, mpi_character, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: rrtmgp_coefs_sw_file")
+   call mpi_bcast(iradsw, 1, mpi_integer, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: iradsw")
+   call mpi_bcast(iradlw, 1, mpi_integer, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: iradlw")
+   call mpi_bcast(irad_always, 1, mpi_integer, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: irad_always")
+   call mpi_bcast(use_rad_dt_cosz, 1, mpi_logical, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: use_rad_dt_cosz")
+   call mpi_bcast(spectralflux, 1, mpi_logical, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: spectralflux")
+   call mpi_bcast(use_rad_uniform_angle, 1, mpi_logical, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: use_rad_uniform_angle")
+   call mpi_bcast(rad_uniform_angle, 1, mpi_real8, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: rad_uniform_angle")   
+   call mpi_bcast(graupel_in_rad, 1, mpi_logical, mstrid, mpicom, ierr)
+   if (ierr /= 0) call endrun(sub//": FATAL: mpi_bcast: graupel_in_rad")
+
+   if (use_rad_uniform_angle .and. rad_uniform_angle == -99._r8) then
+      call endrun(sub//': ERROR - use_rad_uniform_angle is set to .true,' &
+                     //' but rad_uniform_angle is not set ')
+   end if
+
+   ! Set module data
+   coefs_lw_file   = rrtmgp_coefs_lw_file
+   coefs_sw_file   = rrtmgp_coefs_sw_file
+
+   ! Convert iradsw, iradlw and irad_always from hours to timesteps if necessary
+   dtime  = get_step_size()
+   if (iradsw      < 0) iradsw      = nint((-iradsw     *3600._r8)/dtime)
+   if (iradlw      < 0) iradlw      = nint((-iradlw     *3600._r8)/dtime)
+   if (irad_always < 0) irad_always = nint((-irad_always*3600._r8)/dtime)
+
+   !----------------------------------------------------------------------- 
+   ! Print runtime options to log.
+   !-----------------------------------------------------------------------
+
+   if (masterproc) then
+      write(iulog,*) 'RRTMGP radiation scheme parameters:'
+      write(iulog,10) trim(coefs_lw_file), trim(coefs_sw_file), nlwbands, nswbands, &
+         iradsw, iradlw, irad_always, use_rad_dt_cosz, spectralflux, graupel_in_rad
+   end if
+
+10 format('  LW coefficents file: ',                                a/, &
+          '  SW coefficents file: ',                                a/, &
+          '  Number of LW bands:                                 ',i5/, &
+          '  Number of SW bands:                                 ',i5/, &
+          '  Frequency (timesteps) of Shortwave Radiation calc:  ',i5/, &
+          '  Frequency (timesteps) of Longwave Radiation calc:   ',i5/, &
+          '  SW/LW calc done every timestep for first N steps. N=',i5/, &
+          '  Use average zenith angle:                           ',l5/, &
+          '  Output spectrally resolved fluxes:                  ',l5/, &
+          '  Graupel in Radiation Code:                          ',l5/)
+
+end subroutine radiation_readnl
+
+!================================================================================================
+
+subroutine radiation_register
+
+   ! Register radiation fields in the physics buffer
+
+   call pbuf_add_field('QRS' , 'global',dtype_r8,(/pcols,pver/), qrs_idx) ! shortwave radiative heating rate 
+   call pbuf_add_field('QRL' , 'global',dtype_r8,(/pcols,pver/), qrl_idx) ! longwave  radiative heating rate 
+
+   call pbuf_add_field('FSDS' , 'global',dtype_r8,(/pcols/), fsds_idx) ! Surface solar downward flux
+   call pbuf_add_field('FSNS' , 'global',dtype_r8,(/pcols/), fsns_idx) ! Surface net shortwave flux
+   call pbuf_add_field('FSNT' , 'global',dtype_r8,(/pcols/), fsnt_idx) ! Top-of-model net shortwave flux
+
+   call pbuf_add_field('FLNS' , 'global',dtype_r8,(/pcols/), flns_idx) ! Surface net longwave flux
+   call pbuf_add_field('FLNT' , 'global',dtype_r8,(/pcols/), flnt_idx) ! Top-of-model net longwave flux
+
+   ! If the namelist has been configured for preserving the spectral fluxes, then create
+   ! physics buffer variables to store the results.  This data is accessed by CARMA.
+   if (spectralflux) then
+      call pbuf_add_field('SU'  , 'global',dtype_r8,(/pcols,pverp,nswbands/), su_idx) ! shortwave upward flux (per band)
+      call pbuf_add_field('SD'  , 'global',dtype_r8,(/pcols,pverp,nswbands/), sd_idx) ! shortwave downward flux (per band)
+      call pbuf_add_field('LU'  , 'global',dtype_r8,(/pcols,pverp,nlwbands/), lu_idx) ! longwave upward flux (per band)
+      call pbuf_add_field('LD'  , 'global',dtype_r8,(/pcols,pverp,nlwbands/), ld_idx) ! longwave downward flux (per band)
+   end if
+
+   ! Register fields for offline radiation driver.
+   call rad_data_register()
+
+end subroutine radiation_register
+
+!================================================================================================
+
+function radiation_do(op, timestep)
+
+   ! Return true if the specified operation is done this timestep.
+
+   character(len=*), intent(in) :: op             ! name of operation
+   integer, intent(in), optional:: timestep
+   logical                      :: radiation_do   ! return value
+
+   ! Local variables
+   integer :: nstep             ! current timestep number
+   !-----------------------------------------------------------------------
+
+   if (present(timestep)) then
+      nstep = timestep
+   else
+      nstep = get_nstep()
+   end if
+
+   select case (op)
+      case ('sw') ! do a shortwave heating calc this timestep?
+         radiation_do = nstep == 0  .or.  iradsw == 1                     &
+                     .or. (mod(nstep-1,iradsw) == 0  .and.  nstep /= 1)   &
+                     .or. nstep <= irad_always
+      case ('lw') ! do a longwave heating calc this timestep?
+         radiation_do = nstep == 0  .or.  iradlw == 1                     &
+                     .or. (mod(nstep-1,iradlw) == 0  .and.  nstep /= 1)   &
+                     .or. nstep <= irad_always
+      case default
+         call endrun('radiation_do: unknown operation:'//op)
+   end select
+
+end function radiation_do
+
+!================================================================================================
+
+real(r8) function radiation_nextsw_cday()
+  
+   ! If a SW radiation calculation will be done on the next time-step, then return
+   ! the calendar day of that time-step.  Otherwise return -1.0
+
+   ! Local variables
+   integer :: nstep      ! timestep counter
+   logical :: dosw       ! true => do shosrtwave calc   
+   integer :: offset     ! offset for calendar day calculation
+   integer :: dtime      ! integer timestep size
+   real(r8):: caldayp1   ! calendar day of next time-step
+
+   !-----------------------------------------------------------------------
+
+   radiation_nextsw_cday = -1._r8
+   dosw   = .false.
+   nstep  = get_nstep()
+   dtime  = get_step_size()
+   offset = 0
+   do while (.not. dosw)
+      nstep = nstep + 1
+      offset = offset + dtime
+      if (radiation_do('sw', nstep)) then
+         radiation_nextsw_cday = get_curr_calday(offset=offset)
+         dosw = .true.
+      end if
+   end do
+   if(radiation_nextsw_cday == -1._r8) then
+      call endrun('error in radiation_nextsw_cday')
+   end if
+   
+   ! determine if next radiation time-step not equal to next time-step
+   if (get_nstep() >= 1) then
+      caldayp1 = get_curr_calday(offset=int(dtime))
+      if (caldayp1 /= radiation_nextsw_cday) radiation_nextsw_cday = -1._r8
+   end if    
+
+end function radiation_nextsw_cday
+
+!================================================================================================
+
+subroutine radiation_init(pbuf2d)
+
+   ! Initialize the radiation and cloud optics.
+   ! Add fields to the history buffer.
+
+   ! arguments
+   type(physics_buffer_desc), pointer :: pbuf2d(:,:)
+
+   ! local variables
+   character(len=128) :: errmsg
+
+   ! names of gases that are available in the model 
+   ! -- needed for the kdist initialization routines 
+   type(ty_gas_concs) :: available_gases
+
+   integer :: i, icall
+   integer :: nstep                       ! current timestep number
+   logical :: history_amwg                ! output the variables used by the AMWG diag package
+   logical :: history_vdiag               ! output the variables used by the AMWG variability diag package
+   logical :: history_budget              ! output tendencies and state variables for CAM4
+                                          ! temperature, water vapor, cloud ice and cloud
+                                          ! liquid budgets.
+   integer :: history_budget_histfile_num ! history file number for budget fields
+   integer :: ierr, istat
+
+   integer :: dtime
+
+   character(len=*), parameter :: sub = 'radiation_init'
+   !-----------------------------------------------------------------------
+   
+   ! Number of layers in radiation calculation is capped by the number of
+   ! pressure interfaces below 1 Pa.  When the entire model atmosphere is
+   ! below 1 Pa then an extra layer is added to the top of the model for
+   ! the purpose of the radiation calculation.
+   nlay = count( pref_edge(:) > 1._r8 ) ! pascals (0.01 mbar)
+
+   if (nlay == pverp) then
+      ! Top model interface is below 1 Pa.  RRTMGP is active in all model layers plus
+      ! 1 extra layer between model top and 1 Pa.
+      ktopcam = 1
+      ktoprad = 2
+      nlaycam = pver
+   else
+      ! nlay < pverp.  nlay layers are used in radiation calcs, and they are
+      ! all CAM layers.
+      ktopcam = pver - nlay + 1
+      ktoprad = 1
+      nlaycam = nlay
+   end if
+
+   ! Create lowercase version of the gaslist for RRTMGP.  The ty_gas_concs objects
+   ! work with CAM's uppercase names, but other objects that get input from the gas
+   ! concs objects don't work.
+   do i = 1, nradgas
+      gaslist_lc(i) = to_lower(gaslist(i))
+   end do
+
+   errmsg = available_gases%init(gaslist_lc)
+   call stop_on_err(errmsg, sub, 'available_gases%init')
+
+   ! Read RRTMGP coefficients files and initialize kdist objects.
+   call coefs_init(coefs_sw_file, available_gases, kdist_sw)
+   call coefs_init(coefs_lw_file, available_gases, kdist_lw)
+
+   ! Set the sw/lw band boundaries in radconstants.  Also sets
+   ! indicies of specific bands for diagnostic output and COSP input.
+   call set_wavenumber_bands(kdist_sw, kdist_lw)
+
+   ! The spectral band boundaries need to be set before this init is called.
+   call rrtmgp_inputs_init(ktopcam, ktoprad)
+
+   ! initialize output fields for offline driver
+   call rad_data_init(pbuf2d)
+
+   call cloud_rad_props_init()
+  
+   cld_idx      = pbuf_get_index('CLD')
+   cldfsnow_idx = pbuf_get_index('CLDFSNOW', errcode=ierr)
+   cldfgrau_idx = pbuf_get_index('CLDFGRAU', errcode=ierr)
+
+   if (is_first_step()) then
+      call pbuf_set_field(pbuf2d, qrl_idx, 0._r8)
+   end if
+
+   ! Set the radiation timestep for cosz calculations if requested using
+   ! the adjusted iradsw value from radiation
+   if (use_rad_dt_cosz)  then
+      dtime  = get_step_size()
+      dt_avg = iradsw*dtime
+   end if
+
+   ! Surface components to get radiation computed today
+   if (.not. is_first_restart_step()) then
+      nextsw_cday = get_curr_calday()
+   end if
+
+   call phys_getopts(history_amwg_out   = history_amwg,    &
+                     history_vdiag_out  = history_vdiag,   &
+                     history_budget_out = history_budget,  &
+                     history_budget_histfile_num_out = history_budget_histfile_num)
+
+   ! "irad_always" is number of time steps to execute radiation continuously from
+   ! start of initial OR restart run
+   nstep = get_nstep()
+   if (irad_always > 0) then
+      irad_always = irad_always + nstep
+   end if
+
+   if (docosp) call cospsimulator_intr_init()
+
+   allocate(cosp_cnt(begchunk:endchunk), stat=istat)
+   call handle_allocate_error(istat, sub, 'cosp_cnt')
+   if (is_first_restart_step()) then
+      cosp_cnt(begchunk:endchunk) = cosp_cnt_init
+   else
+      cosp_cnt(begchunk:endchunk) = 0     
+   end if
+
+   ! Add fields to history buffer
+
+   call addfld('TOT_CLD_VISTAU',  (/ 'lev' /), 'A',   '1',             &
+               'Total gbx cloud extinction visible sw optical depth',  &
+               sampling_seq='rad_lwsw', flag_xyfill=.true.)
+   call addfld('TOT_ICLD_VISTAU', (/ 'lev' /), 'A',  '1',              &
+               'Total in-cloud extinction visible sw optical depth',   &
+               sampling_seq='rad_lwsw', flag_xyfill=.true.)
+   call addfld('LIQ_ICLD_VISTAU', (/ 'lev' /), 'A',  '1', &
+               'Liquid in-cloud extinction visible sw optical depth',  &
+               sampling_seq='rad_lwsw', flag_xyfill=.true.)
+   call addfld('ICE_ICLD_VISTAU', (/ 'lev' /), 'A',  '1',              &
+               'Ice in-cloud extinction visible sw optical depth',     &
+               sampling_seq='rad_lwsw', flag_xyfill=.true.)
+
+   if (cldfsnow_idx > 0) then
+      call addfld('SNOW_ICLD_VISTAU', (/ 'lev' /), 'A', '1',           &
+                  'Snow in-cloud extinction visible sw optical depth', &
+                  sampling_seq='rad_lwsw', flag_xyfill=.true.)
+   end if
+   if (cldfgrau_idx > 0 .and. graupel_in_rad) then
+      call addfld('GRAU_ICLD_VISTAU', (/ 'lev' /), 'A', '1',           &
+                  'Graupel in-cloud extinction visible sw optical depth', &
+                  sampling_seq='rad_lwsw', flag_xyfill=.true.)
+   endif
+
+   ! get list of active radiation calls
+   call rad_cnst_get_call_list(active_calls)
+
+   ! Add shortwave radiation fields to history master field list.
+
+   do icall = 0, N_DIAG
+
+      if (active_calls(icall)) then
+
+         call addfld('SOLIN'//diag(icall),    horiz_only,   'A', 'W/m2', &
+                     'Solar insolation', sampling_seq='rad_lwsw')
+         call addfld('QRS'//diag(icall),      (/ 'lev' /),  'A', 'K/s',  &
+                     'Solar heating rate', sampling_seq='rad_lwsw')
+         call addfld('QRSC'//diag(icall),     (/ 'lev' /),  'A', 'K/s',  &
+                     'Clearsky solar heating rate', sampling_seq='rad_lwsw')
+         call addfld('FSNT'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Net solar flux at top of model', sampling_seq='rad_lwsw')
+         call addfld('FSNTC'//diag(icall),    horiz_only,   'A', 'W/m2', &
+                     'Clearsky net solar flux at top of model', sampling_seq='rad_lwsw')
+         call addfld('FSNTOA'//diag(icall),   horiz_only,   'A', 'W/m2', &
+                     'Net solar flux at top of atmosphere', sampling_seq='rad_lwsw')
+         call addfld('FSNTOAC'//diag(icall),  horiz_only,   'A', 'W/m2', &
+                     'Clearsky net solar flux at top of atmosphere', sampling_seq='rad_lwsw')
+         call addfld('SWCF'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Shortwave cloud forcing', sampling_seq='rad_lwsw')
+         call addfld('FSUTOA'//diag(icall),   horiz_only,   'A', 'W/m2', &
+                     'Upwelling solar flux at top of atmosphere', sampling_seq='rad_lwsw')
+         call addfld('FSNIRTOA'//diag(icall), horiz_only,   'A', 'W/m2', &
+                     'Net near-infrared flux (Nimbus-7 WFOV) at top of atmosphere', sampling_seq='rad_lwsw')
+         call addfld('FSNRTOAC'//diag(icall), horiz_only,   'A', 'W/m2', &
+                      'Clearsky net near-infrared flux (Nimbus-7 WFOV) at top of atmosphere', sampling_seq='rad_lwsw')
+         call addfld('FSNRTOAS'//diag(icall), horiz_only,   'A', 'W/m2', &
+                     'Net near-infrared flux (>= 0.7 microns) at top of atmosphere', sampling_seq='rad_lwsw')
+         call addfld('FSN200'//diag(icall),   horiz_only,   'A', 'W/m2', &
+                     'Net shortwave flux at 200 mb', sampling_seq='rad_lwsw')
+         call addfld('FSN200C'//diag(icall),  horiz_only,   'A', 'W/m2', &
+                     'Clearsky net shortwave flux at 200 mb', sampling_seq='rad_lwsw')
+         call addfld('FSNR'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Net solar flux at tropopause', sampling_seq='rad_lwsw')
+         call addfld('SOLL'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Solar downward near infrared direct  to surface', sampling_seq='rad_lwsw')
+         call addfld('SOLS'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Solar downward visible direct  to surface', sampling_seq='rad_lwsw')
+         call addfld('SOLLD'//diag(icall),    horiz_only,   'A', 'W/m2', &
+                     'Solar downward near infrared diffuse to surface', sampling_seq='rad_lwsw')
+         call addfld('SOLSD'//diag(icall),    horiz_only,   'A', 'W/m2', &
+                     'Solar downward visible diffuse to surface', sampling_seq='rad_lwsw')
+         call addfld('FSNS'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Net solar flux at surface', sampling_seq='rad_lwsw')
+         call addfld('FSNSC'//diag(icall),    horiz_only,   'A', 'W/m2', &
+                     'Clearsky net solar flux at surface', sampling_seq='rad_lwsw')
+         call addfld('FSDS'//diag(icall),     horiz_only,   'A', 'W/m2', &
+                     'Downwelling solar flux at surface', sampling_seq='rad_lwsw')
+         call addfld('FSDSC'//diag(icall),    horiz_only,   'A', 'W/m2', &
+                     'Clearsky downwelling solar flux at surface', sampling_seq='rad_lwsw')
+
+         ! Fluxes on CAM grid
+         call addfld('FUS'//diag(icall),      (/ 'ilev' /), 'I', 'W/m2', &
+                     'Shortwave upward flux', sampling_seq='rad_lwsw')
+         call addfld('FDS'//diag(icall),      (/ 'ilev' /), 'I', 'W/m2', &
+                     'Shortwave downward flux', sampling_seq='rad_lwsw')
+         call addfld('FUSC'//diag(icall),     (/ 'ilev' /), 'I', 'W/m2', &
+                     'Shortwave clear-sky upward flux', sampling_seq='rad_lwsw')
+         call addfld('FDSC'//diag(icall),     (/ 'ilev' /), 'I', 'W/m2', &
+                     'Shortwave clear-sky downward flux', sampling_seq='rad_lwsw')
+
+         if (history_amwg) then
+            call add_default('SOLIN'//diag(icall),   1, ' ')
+            call add_default('QRS'//diag(icall),     1, ' ')
+            call add_default('FSNT'//diag(icall),    1, ' ')
+            call add_default('FSNTC'//diag(icall),   1, ' ')
+            call add_default('FSNTOA'//diag(icall),  1, ' ')
+            call add_default('FSNTOAC'//diag(icall), 1, ' ')
+            call add_default('SWCF'//diag(icall),    1, ' ')
+            call add_default('FSNS'//diag(icall),    1, ' ')
+            call add_default('FSNSC'//diag(icall),   1, ' ')
+            call add_default('FSUTOA'//diag(icall),  1, ' ')
+            call add_default('FSDSC'//diag(icall),   1, ' ')
+            call add_default('FSDS'//diag(icall),    1, ' ')
+         endif
+
+      end if
+   end do
+
+   if (scm_crm_mode) then
+      call add_default('FUS     ', 1, ' ')
+      call add_default('FUSC    ', 1, ' ')
+      call add_default('FDS     ', 1, ' ')
+      call add_default('FDSC    ', 1, ' ')
+   endif
+
+   ! Add longwave radiation fields to history master field list.
+
+   do icall = 0, N_DIAG
+
+      if (active_calls(icall)) then
+         call addfld('QRL'//diag(icall),     (/ 'lev' /), 'A', 'K/s',  &
+                     'Longwave heating rate', sampling_seq='rad_lwsw')
+         call addfld('QRLC'//diag(icall),    (/ 'lev' /), 'A', 'K/s',  &
+                     'Clearsky longwave heating rate', sampling_seq='rad_lwsw')
+         call addfld('FLNT'//diag(icall),    horiz_only,  'A', 'W/m2', &
+                     'Net longwave flux at top of model', sampling_seq='rad_lwsw')
+         call addfld('FLNTC'//diag(icall),   horiz_only,  'A', 'W/m2', &
+                     'Clearsky net longwave flux at top of model', sampling_seq='rad_lwsw')
+         call addfld('FLUT'//diag(icall),    horiz_only,  'A', 'W/m2', &
+                     'Upwelling longwave flux at top of model', sampling_seq='rad_lwsw')
+         call addfld('FLUTC'//diag(icall),   horiz_only,  'A', 'W/m2', &
+                     'Clearsky upwelling longwave flux at top of model', sampling_seq='rad_lwsw')
+         call addfld('LWCF'//diag(icall),    horiz_only,  'A', 'W/m2', &
+                     'Longwave cloud forcing', sampling_seq='rad_lwsw')
+         call addfld('FLN200'//diag(icall),  horiz_only,  'A', 'W/m2', &
+                     'Net longwave flux at 200 mb', sampling_seq='rad_lwsw')
+         call addfld('FLN200C'//diag(icall), horiz_only,  'A', 'W/m2', &
+                     'Clearsky net longwave flux at 200 mb', sampling_seq='rad_lwsw')
+         call addfld('FLNR'//diag(icall),    horiz_only,  'A', 'W/m2', &
+                     'Net longwave flux at tropopause', sampling_seq='rad_lwsw')
+         call addfld('FLNS'//diag(icall),    horiz_only,  'A', 'W/m2', &
+                     'Net longwave flux at surface', sampling_seq='rad_lwsw')
+         call addfld('FLNSC'//diag(icall),   horiz_only,  'A', 'W/m2', &
+                     'Clearsky net longwave flux at surface', sampling_seq='rad_lwsw')
+         call addfld('FLDS'//diag(icall),    horiz_only,  'A', 'W/m2', &
+                     'Downwelling longwave flux at surface', sampling_seq='rad_lwsw')
+         call addfld('FLDSC'//diag(icall),   horiz_only,  'A', 'W/m2', &
+                     'Clearsky Downwelling longwave flux at surface', sampling_seq='rad_lwsw')
+
+         ! Fluxes on CAM grid
+         call addfld('FUL'//diag(icall),    (/ 'ilev' /), 'I', 'W/m2', &
+                     'Longwave upward flux', sampling_seq='rad_lwsw')
+         call addfld('FDL'//diag(icall),    (/ 'ilev' /), 'I', 'W/m2', &
+                     'Longwave downward flux', sampling_seq='rad_lwsw')
+         call addfld('FULC'//diag(icall),   (/ 'ilev' /), 'I', 'W/m2', &
+                     'Longwave clear-sky upward flux', sampling_seq='rad_lwsw')
+         call addfld('FDLC'//diag(icall),   (/ 'ilev' /), 'I', 'W/m2', &
+                     'Longwave clear-sky downward flux', sampling_seq='rad_lwsw')
+
+         if (history_amwg) then
+            call add_default('QRL'//diag(icall),   1, ' ')
+            call add_default('FLNT'//diag(icall),  1, ' ')
+            call add_default('FLNTC'//diag(icall), 1, ' ')
+            call add_default('FLUT'//diag(icall),  1, ' ')
+            call add_default('FLUTC'//diag(icall), 1, ' ')
+            call add_default('LWCF'//diag(icall),  1, ' ')
+            call add_default('FLNS'//diag(icall),  1, ' ')
+            call add_default('FLNSC'//diag(icall), 1, ' ')
+            call add_default('FLDS'//diag(icall),  1, ' ')
+         end if
+
+      end if
+   end do
+
+   call addfld('EMIS', (/ 'lev' /), 'A', '1', 'Cloud longwave emissivity')
+
+   if (scm_crm_mode) then
+      call add_default ('FUL     ', 1, ' ')
+      call add_default ('FULC    ', 1, ' ')
+      call add_default ('FDL     ', 1, ' ')
+      call add_default ('FDLC    ', 1, ' ')
+   endif
+
+   ! Heating rate needed for d(theta)/dt computation
+   call addfld ('HR',(/ 'lev' /), 'A','K/s','Heating rate needed for d(theta)/dt computation')
+
+   if ( history_budget .and. history_budget_histfile_num > 1 ) then
+      call add_default ('QRL     ', history_budget_histfile_num, ' ')
+      call add_default ('QRS     ', history_budget_histfile_num, ' ')
+   end if
+
+   if (history_vdiag) then
+      call add_default('FLUT', 2, ' ')
+      call add_default('FLUT', 3, ' ')
+   end if
+   
+end subroutine radiation_init
+
+!===============================================================================
+
+subroutine radiation_define_restart(file)
+
+   ! define variables to be written to restart file
+
+   ! arguments
+   type(file_desc_t), intent(inout) :: file
+
+   ! local variables
+   integer :: ierr
+   !----------------------------------------------------------------------------
+
+   call pio_seterrorhandling(file, PIO_BCAST_ERROR)
+
+   ierr = pio_def_var(file, 'nextsw_cday', pio_double, nextsw_cday_desc)
+   ierr = pio_put_att(file, nextsw_cday_desc, 'long_name', 'future radiation calday for surface models')
+   if (docosp) then
+      ierr = pio_def_var(File, 'cosp_cnt_init', pio_int, cospcnt_desc)
+   end if
+
+end subroutine radiation_define_restart
+  
+!===============================================================================
+
+subroutine radiation_write_restart(file)
+
+   ! write variables to restart file
+
+   ! arguments
+   type(file_desc_t), intent(inout) :: file
+
+   ! local variables
+   integer :: ierr
+   !----------------------------------------------------------------------------
+   ierr = pio_put_var(File, nextsw_cday_desc, (/ nextsw_cday /))
+   if (docosp) then
+      ierr = pio_put_var(File, cospcnt_desc, (/cosp_cnt(begchunk)/))
+   end if
+
+end subroutine radiation_write_restart
+  
+!===============================================================================
+
+subroutine radiation_read_restart(file)
+
+   ! read variables from restart file
+
+   ! arguments
+   type(file_desc_t), intent(inout) :: file
+
+   ! local variables
+   integer :: ierr
+   type(var_desc_t) :: vardesc
+   integer :: err_handling
+
+   !----------------------------------------------------------------------------
+   if (docosp) then
+      call pio_seterrorhandling(File, PIO_BCAST_ERROR, err_handling)
+      ierr = pio_inq_varid(File, 'cosp_cnt_init', vardesc)
+      call pio_seterrorhandling(File, err_handling)
+      if (ierr /= PIO_NOERR) then
+         cosp_cnt_init = 0
+      else
+         ierr = pio_get_var(File, vardesc, cosp_cnt_init)
+      end if
+   end if
+
+   ierr = pio_inq_varid(file, 'nextsw_cday', vardesc)
+   ierr = pio_get_var(file, vardesc, nextsw_cday)
+
+
+end subroutine radiation_read_restart
+  
+!===============================================================================
+
+subroutine radiation_tend( &
+   state, ptend, pbuf, cam_out, cam_in, net_flx, rd_out)
+
+   !----------------------------------------------------------------------- 
+   ! 
+   ! CAM driver for radiation computation.
+   ! 
+   !-----------------------------------------------------------------------
+
+   ! Location/Orbital Parameters for cosine zenith angle
+   use phys_grid,          only: get_rlat_all_p, get_rlon_all_p
+   use cam_control_mod,    only: eccen, mvelpp, lambm0, obliqr
+   use shr_orb_mod,        only: shr_orb_decl, shr_orb_cosz
+
+   use rrtmgp_inputs,      only: rrtmgp_set_state, rrtmgp_set_gases_lw, rrtmgp_set_cloud_lw, &
+                                 rrtmgp_set_aer_lw, rrtmgp_set_gases_sw, rrtmgp_set_cloud_sw, &
+                                 rrtmgp_set_aer_sw
+
+   ! RRTMGP drivers for flux calculations.
+   use mo_rte_lw,          only: rte_lw
+   use mo_rte_sw,          only: rte_sw
+
+   use radheat,            only: radheat_tend
+
+   use radiation_data,     only: rad_data_write
+
+   use interpolate_data,   only: vertinterp
+   use tropopause,         only: tropopause_find, TROP_ALG_HYBSTOB, TROP_ALG_CLIMATE
+   use cospsimulator_intr, only: docosp, cospsimulator_intr_run, cosp_nradsteps
+
+
+   ! Arguments
+   type(physics_state), intent(in), target :: state
+   type(physics_ptend), intent(out)        :: ptend
+   type(physics_buffer_desc), pointer      :: pbuf(:)
+   type(cam_out_t),     intent(inout)      :: cam_out
+   type(cam_in_t),      intent(in)         :: cam_in
+   real(r8),            intent(out)        :: net_flx(pcols)
+
+   type(rad_out_t), target, optional, intent(out) :: rd_out
+
+
+   ! Local variables
+   type(rad_out_t), pointer :: rd  ! allow rd_out to be optional by allocating a local object
+                                   ! if the argument is not present
+   logical  :: write_output
+  
+   integer  :: i, k, istat
+   integer  :: lchnk, ncol
+   logical  :: dosw, dolw
+   integer  :: icall           ! loop index for climate/diagnostic radiation calls
+
+   real(r8) :: calday          ! current calendar day
+   real(r8) :: delta           ! Solar declination angle  in radians
+   real(r8) :: eccf            ! Earth orbit eccentricity factor
+   real(r8) :: clat(pcols)     ! current latitudes(radians)
+   real(r8) :: clon(pcols)     ! current longitudes(radians)
+   real(r8) :: coszrs(pcols)   ! Cosine solar zenith angle
+
+   ! Gathered indices of day and night columns 
+   !  chunk_column_index = IdxDay(daylight_column_index)
+   integer :: Nday           ! Number of daylight columns
+   integer :: Nnite          ! Number of night columns
+   integer :: IdxDay(pcols)  ! chunk indices of daylight columns
+   integer :: IdxNite(pcols) ! chunk indices of night columns
+
+   integer :: itim_old
+
+   real(r8), pointer :: cld(:,:)      ! cloud fraction
+   real(r8), pointer :: cldfsnow(:,:) ! cloud fraction of just "snow clouds"
+   real(r8), pointer :: cldfgrau(:,:) ! cloud fraction of just "graupel clouds"
+   real(r8)          :: cldfprime(pcols,pver)   ! combined cloud fraction
+   real(r8), pointer :: qrs(:,:) ! shortwave radiative heating rate 
+   real(r8), pointer :: qrl(:,:) ! longwave  radiative heating rate 
+   real(r8), pointer :: fsds(:)  ! Surface solar down flux
+   real(r8), pointer :: fsns(:)  ! Surface solar absorbed flux
+   real(r8), pointer :: fsnt(:)  ! Net column abs solar flux at model top
+   real(r8), pointer :: flns(:)  ! Srf longwave cooling (up-down) flux
+   real(r8), pointer :: flnt(:)  ! Net outgoing lw flux at model top
+
+   real(r8), pointer, dimension(:,:,:) :: su => NULL()  ! shortwave spectral flux up
+   real(r8), pointer, dimension(:,:,:) :: sd => NULL()  ! shortwave spectral flux down
+   real(r8), pointer, dimension(:,:,:) :: lu => NULL()  ! longwave  spectral flux up
+   real(r8), pointer, dimension(:,:,:) :: ld => NULL()  ! longwave  spectral flux down
+
+   ! tropopause diagnostic
+   integer  :: troplev(pcols)
+   real(r8) :: p_trop(pcols)
+
+   ! state data passed to radiation calc
+   real(r8), allocatable :: t_sfc(:)
+   real(r8), allocatable :: emis_sfc(:,:)
+   real(r8), allocatable :: t_rad(:,:)
+   real(r8), allocatable :: pmid_rad(:,:)
+   real(r8), allocatable :: pint_rad(:,:)
+   real(r8), allocatable :: t_day(:,:)
+   real(r8), allocatable :: pmid_day(:,:)
+   real(r8), allocatable :: pint_day(:,:)
+   real(r8), allocatable :: coszrs_day(:)
+   real(r8), allocatable :: alb_dir(:,:)
+   real(r8), allocatable :: alb_dif(:,:)
+
+   ! in-cloud optical depths for COSP
+   real(r8) :: cld_tau_cloudsim(pcols,pver)    ! liq + ice
+   real(r8) :: snow_tau_cloudsim(pcols,pver)   ! snow
+   real(r8) :: grau_tau_cloudsim(pcols,pver)   ! graupel
+   real(r8) :: cld_lw_abs_cloudsim(pcols,pver) ! liq + ice
+   real(r8) :: snow_lw_abs_cloudsim(pcols,pver)! snow
+   real(r8) :: grau_lw_abs_cloudsim(pcols,pver)! graupel
+
+   ! Set vertical indexing in RRTMGP to be the same as CAM (top to bottom).
+   logical, parameter :: top_at_1 = .true.
+
+   ! TOA solar flux on RRTMGP g-points
+   real(r8), allocatable :: toa_flux(:,:)
+   ! TSI from RRTMGP data (from sum over g-point representation)
+   real(r8) :: tsi_ref
+   
+   ! Planck sources for LW.
+   type(ty_source_func_lw) :: sources_lw
+
+   ! Gas volume mixing ratios.  Use separate objects for LW and SW because SW only does
+   ! calculations for daylight columns.
+   ! These objects have a final method which deallocates the internal memory when they
+   ! go out of scope (i.e., when radiation_tend returns), so no need for explicit deallocation.
+   type(ty_gas_concs) :: gas_concs_lw
+   type(ty_gas_concs) :: gas_concs_sw
+
+   ! Atmosphere optics.  This object is initialized with gas optics, then is incremented
+   ! by the aerosol optics for the clear-sky radiative flux calculations, and then
+   ! incremented again by the cloud optics for the all-sky radiative flux calculations.
+   type(ty_optical_props_1scl) :: atm_optics_lw
+   type(ty_optical_props_2str) :: atm_optics_sw
+
+   ! Cloud optical properties objects (McICA sampling of cloud optical properties).
+   type(ty_optical_props_1scl) :: cloud_lw
+   type(ty_optical_props_2str) :: cloud_sw
+
+   ! Aerosol optical properties objects.
+   type(ty_optical_props_1scl) :: aer_lw
+   type(ty_optical_props_2str) :: aer_sw
+
+   ! Flux objects contain all fluxes computed by RRTMGP.
+   ! SW allsky fluxes always include spectrally resolved fluxes needed for surface models.
+   type(ty_fluxes_byband) :: fsw
+   ! LW allsky fluxes only need spectrally resolved fluxes when spectralflux=.true.
+   type(ty_fluxes_byband) :: flw
+   ! Only broadband fluxes needed for clear sky (diagnostics).
+   type(ty_fluxes_broadband) :: fswc, flwc
+
+   ! Arrays for output diagnostics on CAM grid.
+   real(r8) :: fns(pcols,pverp)     ! net shortwave flux
+   real(r8) :: fcns(pcols,pverp)    ! net clear-sky shortwave flux
+   real(r8) :: fnl(pcols,pverp)     ! net longwave flux
+   real(r8) :: fcnl(pcols,pverp)    ! net clear-sky longwave flux
+
+   ! for COSP
+   real(r8) :: emis(pcols,pver)        ! Cloud longwave emissivity
+   real(r8) :: gb_snow_tau(pcols,pver) ! grid-box mean snow_tau
+   real(r8) :: gb_snow_lw(pcols,pver)  ! grid-box mean LW snow optical depth
+
+   real(r8) :: ftem(pcols,pver)        ! Temporary workspace for outfld variables
+
+   character(len=128) :: errmsg
+   character(len=*), parameter :: sub = 'radiation_tend'
+   !--------------------------------------------------------------------------------------
+
+   lchnk = state%lchnk
+   ncol = state%ncol
+
+   if (present(rd_out)) then
+      rd => rd_out
+      write_output = .false.
+   else
+      allocate(rd, stat=istat)
+      call handle_allocate_error(istat, sub, 'rd')
+      write_output = .true.
+   end if
+
+   dosw = radiation_do('sw', get_nstep())      ! do shortwave radiation calc this timestep?
+   dolw = radiation_do('lw', get_nstep())      ! do longwave radiation calc this timestep?
+
+   ! Cosine solar zenith angle for current time step
+   calday = get_curr_calday()
+   call get_rlat_all_p(lchnk, ncol, clat)
+   call get_rlon_all_p(lchnk, ncol, clon)
+
+   call shr_orb_decl(calday, eccen, mvelpp, lambm0, obliqr, &
+                     delta, eccf)
+
+   if (use_rad_uniform_angle) then
+      do i = 1, ncol
+         coszrs(i) = shr_orb_cosz(calday, clat(i), clon(i), delta, dt_avg, &
+                                  uniform_angle=rad_uniform_angle)
+      end do
+   else
+      do i = 1, ncol
+         ! if dt_avg /= 0, it triggers using avg coszrs
+         coszrs(i) = shr_orb_cosz(calday, clat(i), clon(i), delta, dt_avg)
+      end do
+   end if
+
+   ! Gather night/day column indices.
+   Nday = 0
+   Nnite = 0
+   do i = 1, ncol
+      if ( coszrs(i) > 0.0_r8 ) then
+         Nday = Nday + 1
+         IdxDay(Nday) = i
+      else
+         Nnite = Nnite + 1
+         IdxNite(Nnite) = i
+      end if
+   end do
+
+   ! Associate pointers to physics buffer fields
+   itim_old = pbuf_old_tim_idx()
+   nullify(cldfsnow)
+   if (cldfsnow_idx > 0) then
+      call pbuf_get_field(pbuf, cldfsnow_idx, cldfsnow, start=(/1,1,itim_old/), kount=(/pcols,pver,1/) )
+   end if
+   nullify(cldfgrau)
+   if (cldfgrau_idx > 0 .and. graupel_in_rad) then
+      call pbuf_get_field(pbuf, cldfgrau_idx, cldfgrau, start=(/1,1,itim_old/), kount=(/pcols,pver,1/) )
+   endif
+
+   call pbuf_get_field(pbuf, cld_idx, cld, start=(/1,1,itim_old/), kount=(/pcols,pver,1/) )
+
+   call pbuf_get_field(pbuf, qrs_idx, qrs)
+   call pbuf_get_field(pbuf, qrl_idx, qrl)
+
+   call pbuf_get_field(pbuf, fsns_idx, fsns)
+   call pbuf_get_field(pbuf, fsnt_idx, fsnt)
+   call pbuf_get_field(pbuf, fsds_idx, fsds)
+   call pbuf_get_field(pbuf, flns_idx, flns)
+   call pbuf_get_field(pbuf, flnt_idx, flnt)
+
+   if (spectralflux) then
+      call pbuf_get_field(pbuf, su_idx, su)
+      call pbuf_get_field(pbuf, sd_idx, sd)
+      call pbuf_get_field(pbuf, lu_idx, lu)
+      call pbuf_get_field(pbuf, ld_idx, ld)
+   end if
+
+   ! Allocate the flux arrays and init to zero.
+   call initialize_rrtmgp_fluxes(nday, nlay+1, nswbands, fsw, do_direct=.true.)
+   call initialize_rrtmgp_fluxes(nday, nlay+1, nswbands, fswc, do_direct=.true.)
+   call initialize_rrtmgp_fluxes(ncol, nlay+1, nlwbands, flw)
+   call initialize_rrtmgp_fluxes(ncol, nlay+1, nlwbands, flwc)
+
+   !  For CRM, make cloud equal to input observations:
+   if (scm_crm_mode .and. have_cld) then
+      do k = 1, pver
+         cld(:ncol,k)= cldobs(k)
+      end do
+   end if
+
+   ! Find tropopause height if needed for diagnostic output
+   if (hist_fld_active('FSNR') .or. hist_fld_active('FLNR')) then
+      call tropopause_find(state, troplev, tropP=p_trop, primary=TROP_ALG_HYBSTOB, &
+                           backup=TROP_ALG_CLIMATE)
+   end if
+
+   ! Get time of next radiation calculation - albedos will need to be
+   ! calculated by each surface model at this time
+   nextsw_cday = radiation_nextsw_cday()
+
+   if (dosw .or. dolw) then
+
+      allocate( &
+         t_sfc(ncol), emis_sfc(nlwbands,ncol), toa_flux(nday,nswgpts),     &
+         t_rad(ncol,nlay), pmid_rad(ncol,nlay), pint_rad(ncol,nlay+1),     &
+         t_day(nday,nlay), pmid_day(nday,nlay), pint_day(nday,nlay+1),     &
+         coszrs_day(nday), alb_dir(nswbands,nday), alb_dif(nswbands,nday), &
+         stat=istat)
+      call handle_allocate_error(istat, sub, 't_sfc,..,alb_dif')
+
+      ! Prepares state variables, daylit columns, albedos for RRTMGP
+      call rrtmgp_set_state( &
+         state, cam_in, ncol, nlay, nday,             &
+         idxday, coszrs, kdist_sw, t_sfc, emis_sfc,   &
+         t_rad, pmid_rad, pint_rad, t_day, pmid_day,  &
+         pint_day, coszrs_day, alb_dir, alb_dif)
+
+      ! Output the mass per layer, and total column burdens for gas and aerosol
+      ! constituents in the climate list.
+      call rad_cnst_out(0, state, pbuf)
+
+      ! Modified cloud fraction accounts for radiatively active snow and/or graupel
+      call modified_cloud_fraction(ncol, cld, cldfsnow, cldfgrau, cldfprime)
+
+      !========================!
+      ! SHORTWAVE calculations !
+      !========================!
+
+      if (dosw) then
+
+         ! Set cloud optical properties in cloud_sw object.
+         call rrtmgp_set_cloud_sw( &
+            state, pbuf, nlay, nday, idxday,                              &
+            nnite, idxnite, pmid_day, cld, cldfsnow,                      &
+            cldfgrau, cldfprime, graupel_in_rad, kdist_sw, cloud_sw,      &
+            rd%tot_cld_vistau, rd%tot_icld_vistau, rd%liq_icld_vistau,    &
+            rd%ice_icld_vistau, rd%snow_icld_vistau, rd%grau_icld_vistau, &
+            cld_tau_cloudsim, snow_tau_cloudsim, grau_tau_cloudsim )
+
+         if (write_output) then
+            call radiation_output_cld(lchnk, rd)
+         end if
+
+         ! If no daylight columns, can't create empty RRTMGP objects
+         if (nday > 0) then
+
+            ! Initialize object for gas concentrations.
+            errmsg = gas_concs_sw%init(gaslist_lc)
+            call stop_on_err(errmsg, sub, 'gas_concs_sw%init')
+
+            ! Initialize object for combined gas + aerosol + cloud optics.
+            ! Allocates arrays for properties represented on g-points.
+            errmsg = atm_optics_sw%alloc_2str(nday, nlay, kdist_sw)
+            call stop_on_err(errmsg, sub, 'atm_optics_sw%alloc_2str')
+
+            ! Initialize object for SW aerosol optics.  Allocates arrays 
+            ! for properties represented by band.
+            errmsg = aer_sw%alloc_2str(nday, nlay, kdist_sw%get_band_lims_wavenumber()) 
+            call stop_on_err(errmsg, sub, 'aer_sw%alloc_2str')
+
+         end if
+
+         ! The climate (icall==0) calculation must occur last.
+         do icall = N_DIAG, 0, -1
+            if (active_calls(icall)) then
+
+               if (nday > 0) then
+
+                  ! Set gas volume mixing ratios for this call in gas_concs_sw.
+                  call rrtmgp_set_gases_sw( &
+                     icall, state, pbuf, nlay, nday, &
+                     idxday, gas_concs_sw)
+
+                  ! Compute the gas optics (stored in atm_optics_sw).
+                  ! toa_flux is the reference solar source from RRTMGP data.
+                  errmsg = kdist_sw%gas_optics( &
+                     pmid_day, pint_day, t_day, gas_concs_sw, atm_optics_sw, &
+                     toa_flux)
+                  call stop_on_err(errmsg, sub, 'kdist_sw%gas_optics')
+
+                  ! Scale the solar source
+                  tsi_ref = sum(toa_flux(1,:))
+                  toa_flux = toa_flux * sol_tsi * eccf / tsi_ref
+
+               end if
+
+               ! Set SW aerosol optical properties in the aer_sw object.
+               ! This call made even when no daylight columns because it does some
+               ! diagnostic aerosol output.
+               call rrtmgp_set_aer_sw( &
+                  icall, state, pbuf, nday, idxday, nnite, idxnite, aer_sw)
+                  
+               if (nday > 0) then
+
+                  ! Increment the gas optics (in atm_optics_sw) by the aerosol optics in aer_sw.
+                  errmsg = aer_sw%increment(atm_optics_sw)
+                  call stop_on_err(errmsg, sub, 'aer_sw%increment')
+
+                  ! Compute clear-sky fluxes.
+                  errmsg = rte_sw(&
+                     atm_optics_sw, top_at_1, coszrs_day, toa_flux, &
+                     alb_dir, alb_dif, fswc)
+                  call stop_on_err(errmsg, sub, 'clear-sky rte_sw')
+
+                  ! Increment the aerosol+gas optics (in atm_optics_sw) by the cloud optics in cloud_sw.
+                  errmsg = cloud_sw%increment(atm_optics_sw)
+                  call stop_on_err(errmsg, sub, 'cloud_sw%increment')
+
+                  ! Compute all-sky fluxes.
+                  errmsg = rte_sw(&
+                     atm_optics_sw, top_at_1, coszrs_day, toa_flux, &
+                     alb_dir, alb_dif, fsw)
+                  call stop_on_err(errmsg, sub, 'all-sky rte_sw')
+
+               end if
+
+               ! Transform RRTMGP outputs to CAM outputs and compute heating rates.
+               call set_sw_diags()
+
+               if (write_output) then
+                  call radiation_output_sw(lchnk, ncol, icall, rd, pbuf, cam_out)
+               end if
+
+            end if ! (active_calls(icall))
+         end do    ! loop over diagnostic calcs (icall)
+         
+      else
+         ! SW calc not done.  pbuf carries Q*dp across timesteps.
+         ! Convert to Q before calling radheat_tend.
+         qrs(:ncol,:) = qrs(:ncol,:) / state%pdel(:ncol,:)
+      end if  ! if (dosw)
+
+      !=======================!
+      ! LONGWAVE calculations !
+      !=======================!
+
+      if (dolw) then
+
+         ! Initialize object for Planck sources.
+         errmsg = sources_lw%alloc(ncol, nlay, kdist_lw)
+         call stop_on_err(errmsg, sub, 'sources_lw%alloc')
+
+         ! Set cloud optical properties in cloud_lw object.
+         call rrtmgp_set_cloud_lw( &
+            state, pbuf, ncol, nlay, nlaycam, &
+            cld, cldfsnow, cldfgrau, cldfprime, graupel_in_rad, &
+            kdist_lw, cloud_lw, cld_lw_abs_cloudsim, snow_lw_abs_cloudsim, grau_lw_abs_cloudsim)
+
+         ! Initialize object for gas concentrations
+         errmsg = gas_concs_lw%init(gaslist_lc)
+         call stop_on_err(errmsg, sub, 'gas_concs_lw%init')
+
+         ! Initialize object for combined gas + aerosol + cloud optics.
+         errmsg = atm_optics_lw%alloc_1scl(ncol, nlay, kdist_lw)
+         call stop_on_err(errmsg, sub, 'atm_optics_lw%alloc_1scl')
+
+         ! Initialize object for LW aerosol optics.
+         errmsg = aer_lw%alloc_1scl(ncol, nlay, kdist_lw%get_band_lims_wavenumber())
+         call stop_on_err(errmsg, sub, 'aer_lw%alloc_1scl')
+
+         ! The climate (icall==0) calculation must occur last.
+         do icall = N_DIAG, 0, -1
+
+            if (active_calls(icall)) then
+
+               ! Set gas volume mixing ratios for this call in gas_concs_lw.
+               call rrtmgp_set_gases_lw(icall, state, pbuf, nlay, gas_concs_lw)
+
+               ! Compute the gas optics and Planck sources.
+               errmsg = kdist_lw%gas_optics( &
+                  pmid_rad, pint_rad, t_rad, t_sfc, gas_concs_lw, &
+                  atm_optics_lw, sources_lw)
+               call stop_on_err(errmsg, sub, 'kdist_lw%gas_optics')
+
+               ! Set LW aerosol optical properties in the aer_lw object.
+               call rrtmgp_set_aer_lw(icall, state, pbuf, aer_lw)
+               
+               ! Increment the gas optics by the aerosol optics.
+               errmsg = aer_lw%increment(atm_optics_lw)
+               call stop_on_err(errmsg, sub, 'aer_lw%increment')
+
+               ! Compute clear-sky LW fluxes
+               errmsg = rte_lw(atm_optics_lw, top_at_1, sources_lw, emis_sfc, flwc)
+               call stop_on_err(errmsg, sub, 'clear-sky rte_lw')
+
+               ! Increment the gas+aerosol optics by the cloud optics.
+               errmsg = cloud_lw%increment(atm_optics_lw)
+               call stop_on_err(errmsg, sub, 'cloud_lw%increment')
+
+               ! Compute all-sky LW fluxes
+               errmsg = rte_lw(atm_optics_lw, top_at_1, sources_lw, emis_sfc, flw)
+               call stop_on_err(errmsg, sub, 'all-sky rte_lw')
+
+               ! Transform RRTMGP outputs to CAM outputs and compute heating rates.
+               call set_lw_diags()
+
+               if (write_output) then
+                  call radiation_output_lw(lchnk, ncol, icall, rd, pbuf, cam_out)
+               end if
+
+            end if ! (active_calls(icall))
+         end do    ! loop over diagnostic calcs (icall)
+
+      else
+         ! LW calc not done.  pbuf carries Q*dp across timesteps.
+         ! Convert to Q before calling radheat_tend.
+        qrl(:ncol,:) = qrl(:ncol,:) / state%pdel(:ncol,:)
+      end if  ! if (dolw)
+
+      deallocate( &
+         t_sfc, emis_sfc, toa_flux, t_rad, pmid_rad, pint_rad,  &
+         t_day, pmid_day, pint_day, coszrs_day, alb_dir, alb_dif)
+
+      !================!
+      ! COSP simulator !
+      !================!
+
+      if (docosp) then
+
+         emis(:,:) = 0._r8
+         emis(:ncol,:) = 1._r8 - exp(-cld_lw_abs_cloudsim(:ncol,:))
+         call outfld('EMIS', emis, pcols, lchnk)
+
+         ! compute grid-box mean SW and LW snow optical depth for use by COSP
+         gb_snow_tau(:,:) = 0._r8
+         gb_snow_lw(:,:)  = 0._r8
+         if (cldfsnow_idx > 0) then
+            do i = 1, ncol
+               do k = 1, pver
+                  if (cldfsnow(i,k) > 0._r8) then
+
+                     ! Add graupel to snow tau for cosp
+                     if (cldfgrau_idx > 0 .and. graupel_in_rad) then
+                        gb_snow_tau(i,k) = snow_tau_cloudsim(i,k)*cldfsnow(i,k) + &
+                                           grau_tau_cloudsim(i,k)*cldfgrau(i,k)
+                        gb_snow_lw(i,k)  = snow_lw_abs_cloudsim(i,k)*cldfsnow(i,k) + &
+                                           grau_lw_abs_cloudsim(i,k)*cldfgrau(i,k)
+                     else
+                        gb_snow_tau(i,k) = snow_tau_cloudsim(i,k)*cldfsnow(i,k)
+                        gb_snow_lw(i,k)  = snow_lw_abs_cloudsim(i,k)*cldfsnow(i,k)
+                     end if
+                  end if
+               end do
+            end do
+         end if
+
+         ! advance counter for this timestep (chunk dimension required for thread safety)
+         cosp_cnt(lchnk) = cosp_cnt(lchnk) + 1
+
+         ! if counter is the same as cosp_nradsteps, run cosp and reset counter
+         if (cosp_nradsteps .eq. cosp_cnt(lchnk)) then
+
+            ! N.B.: For snow optical properties, the GRID-BOX MEAN shortwave and longwave
+            !       optical depths are passed.
+            call cospsimulator_intr_run( &
+               state,  pbuf, cam_in, emis, coszrs,                     &
+               cld_swtau_in=cld_tau_cloudsim, snow_tau_in=gb_snow_tau, &
+               snow_emis_in=gb_snow_lw)
+            cosp_cnt(lchnk) = 0
+         end if
+      end if   ! docosp
+      
+   else
+      ! Radiative flux calculations not done.  The quantity Q*dp is carried by the
+      ! physics buffer across timesteps.  It must be converted to Q (dry static energy
+      ! tendency) before being passed to radheat_tend.
+      qrs(:ncol,:) = qrs(:ncol,:) / state%pdel(:ncol,:)
+      qrl(:ncol,:) = qrl(:ncol,:) / state%pdel(:ncol,:)
+
+   end if   ! if (dosw .or. dolw) then
+
+   ! Output for PORT: Parallel Offline Radiative Transport
+   call rad_data_write(pbuf, state, cam_in, coszrs)
+
+   ! Compute net radiative heating tendency.  Note that the WACCM version
+   ! of radheat_tend merges upper atmosphere heating rates with those calculated
+   ! by RRTMGP.
+   call radheat_tend(state, pbuf,  ptend, qrl, qrs, fsns, &
+                     fsnt, flns, flnt, cam_in%asdir, net_flx)
+
+   if (write_output) then
+      ! Compute heating rate for dtheta/dt
+      do k = 1, pver
+         do i = 1, ncol
+            ftem(i,k) = (qrs(i,k) + qrl(i,k))/cpair * (1.e5_r8/state%pmid(i,k))**cappa
+         end do
+      end do
+      call outfld('HR', ftem, pcols, lchnk)
+   end if
+
+   ! The radiative heating rates are carried in the physics buffer across timesteps
+   ! as Q*dp (for energy conservation).
+   qrs(:ncol,:) = qrs(:ncol,:) * state%pdel(:ncol,:)
+   qrl(:ncol,:) = qrl(:ncol,:) * state%pdel(:ncol,:)
+
+   if (.not. present(rd_out)) then
+      deallocate(rd)
+   end if
+   call free_optics_sw(atm_optics_sw)
+   call free_optics_sw(cloud_sw)
+   call free_optics_sw(aer_sw)
+   call free_fluxes(fsw)
+   call free_fluxes(fswc)
+
+   call sources_lw%finalize()
+   call free_optics_lw(cloud_lw)
+   call free_optics_lw(aer_lw)
+   call free_fluxes(flw)
+   call free_fluxes(flwc)
+
+   !-------------------------------------------------------------------------------
+   contains
+   !-------------------------------------------------------------------------------
+
+   subroutine set_sw_diags()
+
+      ! Transform RRTMGP output for CAM and compute heating rates.
+      ! SW fluxes from RRTMGP are on daylight columns only, so expand to
+      ! full chunks for output to CAM history.
+
+      integer :: i
+      real(r8), dimension(size(fsw%bnd_flux_dn,1), &
+                          size(fsw%bnd_flux_dn,2), &
+                          size(fsw%bnd_flux_dn,3)) :: flux_dn_diffuse
+      !-------------------------------------------------------------------------
+
+      ! Initialize to provide 0.0 values for night columns.
+      fns               = 0._r8 ! net sw flux
+      fcns              = 0._r8 ! net sw clearsky flux
+      fsds              = 0._r8 ! downward sw flux at surface
+      rd%fsdsc          = 0._r8 ! downward sw clearsky flux at surface
+      rd%fsutoa         = 0._r8 ! upward sw flux at TOA
+      rd%fsntoa         = 0._r8 ! net sw at TOA
+      rd%fsntoac        = 0._r8 ! net sw clearsky flux at TOA
+      rd%solin          = 0._r8 ! solar irradiance at TOA
+      rd%flux_sw_up     = 0._r8
+      rd%flux_sw_dn     = 0._r8
+      rd%flux_sw_clr_up = 0._r8
+      rd%flux_sw_clr_dn = 0._r8
+
+      qrs      = 0._r8
+      fsns     = 0._r8
+      fsnt     = 0._r8
+      rd%qrsc  = 0._r8
+      rd%fsnsc = 0._r8
+      rd%fsntc = 0._r8
+
+      do i = 1, nday
+         fns(idxday(i),ktopcam:)  = fsw%flux_net(i, ktoprad:)
+         fcns(idxday(i),ktopcam:) = fswc%flux_net(i,ktoprad:)
+         fsds(idxday(i))          = fsw%flux_dn(i, nlay+1)
+         rd%fsdsc(idxday(i))      = fswc%flux_dn(i, nlay+1)
+         rd%fsutoa(idxday(i))     = fsw%flux_up(i, 1)
+         rd%fsntoa(idxday(i))     = fsw%flux_net(i, 1)
+         rd%fsntoac(idxday(i))    = fswc%flux_net(i, 1)
+         rd%solin(idxday(i))      = fswc%flux_dn(i, 1)
+         rd%flux_sw_up(idxday(i),ktopcam:)     = fsw%flux_up(i,ktoprad:)
+         rd%flux_sw_dn(idxday(i),ktopcam:)     = fsw%flux_dn(i,ktoprad:)
+         rd%flux_sw_clr_up(idxday(i),ktopcam:) = fswc%flux_up(i,ktoprad:) 
+         rd%flux_sw_clr_dn(idxday(i),ktopcam:) = fswc%flux_dn(i,ktoprad:)
+      end do
+
+      ! Compute heating rate as a dry static energy tendency.
+      call heating_rate('SW', ncol, fns, qrs)
+      call heating_rate('SW', ncol, fcns, rd%qrsc)
+
+      fsns(:ncol)     = fns(:ncol,pverp)    ! net sw flux at surface
+      fsnt(:ncol)     = fns(:ncol,ktopcam)  ! net sw flux at top-of-model (w/o extra layer)
+      rd%fsnsc(:ncol) = fcns(:ncol,pverp)   ! net sw clearsky flux at surface
+      rd%fsntc(:ncol) = fcns(:ncol,ktopcam) ! net sw clearsky flux at top
+
+      cam_out%netsw(:ncol) = fsns(:ncol)
+
+      ! Output fluxes at 200 mb
+      call vertinterp(ncol, pcols, pverp, state%pint, 20000._r8, fns,  rd%fsn200)
+      call vertinterp(ncol, pcols, pverp, state%pint, 20000._r8, fcns, rd%fsn200c)
+      if (hist_fld_active('FSNR')) then
+         do i = 1,ncol
+            call vertinterp(1, 1, pverp, state%pint(i,:), p_trop(i), fns(i,:), rd%fsnr(i))
+         end do
+      end if
+
+      if (spectralflux) then
+         su  = 0._r8
+         sd  = 0._r8
+         do i = 1, nday
+            su(idxday(i),ktopcam:,:) = fsw%bnd_flux_up(i,ktoprad:,:)
+            sd(idxday(i),ktopcam:,:) = fsw%bnd_flux_dn(i,ktoprad:,:)
+         end do
+      end if
+
+      ! Export surface fluxes
+      ! sols(pcols)      Direct solar rad on surface (< 0.7)
+      ! soll(pcols)      Direct solar rad on surface (>= 0.7)
+      ! RRTMGP: Near-IR bands (1-10), 820-16000 cm-1, 0.625-12.195 microns
+      ! Put half of band 10 in each of the UV/visible and near-IR values,
+      ! since this band straddles 0.7 microns:
+      ! UV/visible bands 10-13, 16000-50000 cm-1, 0.200-0.625 micron
+
+      ! reset fluxes
+      cam_out%sols  = 0.0_r8
+      cam_out%soll  = 0.0_r8
+      cam_out%solsd = 0.0_r8
+      cam_out%solld = 0.0_r8
+
+      ! Calculate diffuse flux from total and direct
+      flux_dn_diffuse = fsw%bnd_flux_dn - fsw%bnd_flux_dn_dir
+
+      do i = 1, nday
+         cam_out%soll(idxday(i)) = sum(fsw%bnd_flux_dn_dir(i,nlay+1,1:9))      &
+                                   + 0.5_r8 * fsw%bnd_flux_dn_dir(i,nlay+1,10) 
+
+         cam_out%sols(idxday(i)) = 0.5_r8 * fsw%bnd_flux_dn_dir(i,nlay+1,10)   &
+                                   + sum(fsw%bnd_flux_dn_dir(i,nlay+1,11:14))
+
+         cam_out%solld(idxday(i)) = sum(flux_dn_diffuse(i,nlay+1,1:9))         &
+                                    + 0.5_r8 * flux_dn_diffuse(i,nlay+1,10)
+         
+         cam_out%solsd(idxday(i)) = 0.5_r8 * flux_dn_diffuse(i, nlay+1, 10)    &
+                                    + sum(flux_dn_diffuse(i,nlay+1,11:14))
+      end do
+
+   end subroutine set_sw_diags
+
+   !-------------------------------------------------------------------------------
+
+   subroutine set_lw_diags()
+
+      ! Set CAM LW diagnostics
+      !----------------------------------------------------------------------------
+ 
+      fnl = 0._r8
+      fcnl = 0._r8
+
+      ! RTE-RRTMGP convention for net is (down - up) **CAM assumes (up - down) !!
+      fnl(:ncol,ktopcam:)  = -1._r8 * flw%flux_net(    :, ktoprad:)
+      fcnl(:ncol,ktopcam:) = -1._r8 * flwc%flux_net(   :, ktoprad:)
+
+      rd%flux_lw_up(:ncol,ktopcam:)     = flw%flux_up( :, ktoprad:)
+      rd%flux_lw_clr_up(:ncol,ktopcam:) = flwc%flux_up(:, ktoprad:)
+      rd%flux_lw_dn(:ncol,ktopcam:)     = flw%flux_dn( :, ktoprad:)
+      rd%flux_lw_clr_dn(:ncol,ktopcam:) = flwc%flux_dn(:, ktoprad:)
+
+      call heating_rate('LW', ncol, fnl, qrl)
+      call heating_rate('LW', ncol, fcnl, rd%qrlc)
+
+      flns(:ncol) = fnl(:ncol, pverp)
+      flnt(:ncol) = fnl(:ncol, ktopcam)
+
+      rd%flnsc(:ncol) = fcnl(:ncol, pverp)
+      rd%flntc(:ncol) = fcnl(:ncol, ktopcam)    ! net lw flux at top-of-model
+
+      cam_out%flwds(:ncol) = flw%flux_dn(:, nlay+1)
+      rd%fldsc(:ncol)      = flwc%flux_dn(:, nlay+1)
+
+      rd%flut(:ncol)  = flw%flux_up(:, ktoprad) 
+      rd%flutc(:ncol) = flwc%flux_up(:, ktoprad)
+
+      ! Output fluxes at 200 mb
+      call vertinterp(ncol, pcols, pverp, state%pint, 20000._r8, fnl,  rd%fln200)
+      call vertinterp(ncol, pcols, pverp, state%pint, 20000._r8, fcnl, rd%fln200c)
+      if (hist_fld_active('FLNR')) then
+         do i = 1,ncol
+            call vertinterp(1, 1, pverp, state%pint(i,:), p_trop(i), fnl(i,:), rd%flnr(i))
+         end do
+      end if
+
+      if (spectralflux) then
+         lu  = 0._r8
+         ld  = 0._r8
+         lu(:ncol, ktopcam:, :)  = flw%bnd_flux_up(:, ktoprad:, :)
+         ld(:ncol, ktopcam:, :)  = flw%bnd_flux_dn(:, ktoprad:, :)
+      end if
+
+   end subroutine set_lw_diags
+
+   !-------------------------------------------------------------------------------
+
+   subroutine heating_rate(type, ncol, flux_net, hrate)
+
+      ! Compute heating rate as a dry static energy tendency
+      
+      ! arguments
+      character(2), intent(in)  :: type ! either LW or SW
+      integer,      intent(in)  :: ncol
+      real(r8),     intent(in)  :: flux_net(pcols,pverp)  ! W/m^2
+      real(r8),     intent(out) :: hrate(pcols,pver)      ! J/kg/s
+
+      ! local vars
+      integer :: k
+
+      ! Initialize for layers where RRTMGP is not providing fluxes.
+      hrate = 0.0_r8
+
+      select case (type)
+      case ('LW')
+
+         do k = ktopcam, pver
+            ! (flux divergence as bottom-MINUS-top) * g/dp
+            hrate(:ncol,k) = (flux_net(:ncol,k+1) - flux_net(:ncol,k)) * &
+                          gravit * state%rpdel(:ncol,k)
+         end do
+
+      case ('SW')
+
+         do k = ktopcam, pver
+            ! top - bottom
+            hrate(:ncol,k) = (flux_net(:ncol,k) - flux_net(:ncol,k+1)) * &
+                          gravit * state%rpdel(:ncol,k)
+         end do
+
+      end select
+
+   end subroutine heating_rate
+
+   !----------------------------------------------------------------------------
+   !            -- end contains statement of radiation_tend --
+   !----------------------------------------------------------------------------
+end subroutine radiation_tend
+
+!===============================================================================
+
+subroutine radiation_output_sw(lchnk, ncol, icall, rd, pbuf, cam_out)
+
+   ! Dump shortwave radiation information to history buffer.
+
+   integer ,               intent(in) :: lchnk
+   integer,                intent(in) :: ncol
+   integer,                intent(in) :: icall
+   type(rad_out_t),        intent(in) :: rd
+   type(physics_buffer_desc), pointer :: pbuf(:)
+   type(cam_out_t),        intent(in) :: cam_out
+
+   ! local variables
+   real(r8), pointer :: qrs(:,:)
+   real(r8), pointer :: fsnt(:)
+   real(r8), pointer :: fsns(:)
+   real(r8), pointer :: fsds(:)
+
+   real(r8) :: ftem(pcols)
+   !----------------------------------------------------------------------------
+
+   call pbuf_get_field(pbuf, qrs_idx,  qrs)
+   call pbuf_get_field(pbuf, fsnt_idx, fsnt)
+   call pbuf_get_field(pbuf, fsns_idx, fsns)
+   call pbuf_get_field(pbuf, fsds_idx, fsds)
+
+   call outfld('SOLIN'//diag(icall),    rd%solin,      pcols, lchnk)
+
+   ! QRS is output as temperature tendency.
+   call outfld('QRS'//diag(icall),      qrs(:ncol,:)/cpair,     ncol, lchnk)
+   call outfld('QRSC'//diag(icall),     rd%qrsc(:ncol,:)/cpair, ncol, lchnk)
+
+   call outfld('FSNT'//diag(icall),    fsnt,               pcols, lchnk)
+   call outfld('FSNTC'//diag(icall),   rd%fsntc,           pcols, lchnk)
+   call outfld('FSNTOA'//diag(icall),  rd%fsntoa,          pcols, lchnk)
+   call outfld('FSNTOAC'//diag(icall), rd%fsntoac,         pcols, lchnk)
+
+   ftem(:ncol) = rd%fsntoa(:ncol) - rd%fsntoac(:ncol)
+   call outfld('SWCF'//diag(icall),     ftem,          pcols, lchnk)
+
+   call outfld('FSUTOA'//diag(icall),   rd%fsutoa,     pcols, lchnk)
+
+   call outfld('FSNIRTOA'//diag(icall), rd%fsnirt,     pcols, lchnk)
+   call outfld('FSNRTOAC'//diag(icall), rd%fsnrtc,     pcols, lchnk)
+   call outfld('FSNRTOAS'//diag(icall), rd%fsnirtsq,   pcols, lchnk)
+
+   call outfld('FSN200'//diag(icall),   rd%fsn200,     pcols, lchnk)
+   call outfld('FSN200C'//diag(icall),  rd%fsn200c,    pcols, lchnk)
+
+   call outfld('FSNR'//diag(icall),     rd%fsnr,       pcols, lchnk)
+
+   call outfld('SOLS'//diag(icall),     cam_out%sols,  pcols, lchnk)
+   call outfld('SOLL'//diag(icall),     cam_out%soll,  pcols, lchnk)
+   call outfld('SOLSD'//diag(icall),    cam_out%solsd, pcols, lchnk)
+   call outfld('SOLLD'//diag(icall),    cam_out%solld, pcols, lchnk)
+
+   call outfld('FSNS'//diag(icall),     fsns,          pcols, lchnk)
+   call outfld('FSNSC'//diag(icall),    rd%fsnsc,      pcols, lchnk)
+
+   call outfld('FSDS'//diag(icall),     fsds,          pcols, lchnk)
+   call outfld('FSDSC'//diag(icall),    rd%fsdsc,      pcols, lchnk)
+
+   call outfld('FUS'//diag(icall),  rd%flux_sw_up,     pcols, lchnk)
+   call outfld('FUSC'//diag(icall), rd%flux_sw_clr_up, pcols, lchnk)
+   call outfld('FDS'//diag(icall),  rd%flux_sw_dn,     pcols, lchnk)
+   call outfld('FDSC'//diag(icall), rd%flux_sw_clr_dn, pcols, lchnk)
+
+end subroutine radiation_output_sw
+
+!===============================================================================
+
+subroutine radiation_output_cld(lchnk, rd)
+
+   ! Dump shortwave cloud optics information to history buffer.
+
+   integer ,        intent(in) :: lchnk
+   type(rad_out_t), intent(in) :: rd
+   !----------------------------------------------------------------------------
+
+   call outfld('TOT_CLD_VISTAU',  rd%tot_cld_vistau,  pcols, lchnk)
+   call outfld('TOT_ICLD_VISTAU', rd%tot_icld_vistau, pcols, lchnk)
+   call outfld('LIQ_ICLD_VISTAU', rd%liq_icld_vistau, pcols, lchnk)
+   call outfld('ICE_ICLD_VISTAU', rd%ice_icld_vistau, pcols, lchnk)
+   if (cldfsnow_idx > 0) then
+      call outfld('SNOW_ICLD_VISTAU', rd%snow_icld_vistau, pcols, lchnk)
+   endif
+   if (cldfgrau_idx > 0 .and. graupel_in_rad) then
+      call outfld('GRAU_ICLD_VISTAU', rd%grau_icld_vistau , pcols, lchnk)
+   endif
+
+end subroutine radiation_output_cld
+
+!===============================================================================
+
+subroutine radiation_output_lw(lchnk, ncol, icall, rd, pbuf, cam_out)
+
+   ! Dump longwave radiation information to history buffer
+
+   integer,                intent(in) :: lchnk
+   integer,                intent(in) :: ncol
+   integer,                intent(in) :: icall  ! icall=0 for climate diagnostics
+   type(rad_out_t),        intent(in) :: rd
+   type(physics_buffer_desc), pointer :: pbuf(:)
+   type(cam_out_t),        intent(in) :: cam_out
+
+   ! local variables
+   real(r8), pointer :: qrl(:,:)
+   real(r8), pointer :: flnt(:)
+   real(r8), pointer :: flns(:)
+
+   real(r8) :: ftem(pcols)
+   !----------------------------------------------------------------------------
+
+   call pbuf_get_field(pbuf, qrl_idx,  qrl)
+   call pbuf_get_field(pbuf, flnt_idx, flnt)
+   call pbuf_get_field(pbuf, flns_idx, flns)
+
+   call outfld('QRL'//diag(icall),     qrl(:ncol,:)/cpair,     ncol, lchnk)
+   call outfld('QRLC'//diag(icall),    rd%qrlc(:ncol,:)/cpair, ncol, lchnk)
+
+   call outfld('FLNT'//diag(icall),    flnt,          pcols, lchnk)
+   call outfld('FLNTC'//diag(icall),   rd%flntc,      pcols, lchnk)
+
+   call outfld('FLUT'//diag(icall),    rd%flut,       pcols, lchnk)
+   call outfld('FLUTC'//diag(icall),   rd%flutc,      pcols, lchnk)
+   
+   ftem(:ncol) = rd%flutc(:ncol) - rd%flut(:ncol)
+   call outfld('LWCF'//diag(icall),    ftem,          pcols, lchnk)
+
+   call outfld('FLN200'//diag(icall),  rd%fln200,     pcols, lchnk)
+   call outfld('FLN200C'//diag(icall), rd%fln200c,    pcols, lchnk)
+
+   call outfld('FLNR'//diag(icall),    rd%flnr,       pcols, lchnk)
+
+   call outfld('FLNS'//diag(icall),    flns,          pcols, lchnk)
+   call outfld('FLNSC'//diag(icall),   rd%flnsc,      pcols, lchnk)
+
+   call outfld('FLDS'//diag(icall),    cam_out%flwds, pcols, lchnk)
+   call outfld('FLDSC'//diag(icall),   rd%fldsc,      pcols, lchnk)
+
+   call outfld('FDL'//diag(icall),  rd%flux_lw_dn,     pcols, lchnk)
+   call outfld('FDLC'//diag(icall), rd%flux_lw_clr_dn, pcols, lchnk)
+   call outfld('FUL'//diag(icall),  rd%flux_lw_up,     pcols, lchnk)
+   call outfld('FULC'//diag(icall), rd%flux_lw_clr_up, pcols, lchnk)
+
+end subroutine radiation_output_lw
+
+!===============================================================================
+
+subroutine coefs_init(coefs_file, available_gases, kdist)
+
+   ! Read data from coefficients file.  Initialize the kdist object.
+   ! available_gases object provides the gas names that CAM provides.
+
+   ! arguments
+   character(len=*),                  intent(in)  :: coefs_file
+   class(ty_gas_concs),               intent(in)  :: available_gases
+   class(ty_gas_optics_rrtmgp),       intent(out) :: kdist
+
+   ! local variables
+   type(file_desc_t) :: fh    ! pio file handle
+   character(len=cl) :: locfn ! path to file on local storage
+
+   ! File dimensions
+   integer ::            &
+      absorber,          &
+      atmos_layer,       &
+      bnd,               &
+      pressure,          &
+      temperature,       &
+      absorber_ext,      &
+      pressure_interp,   &
+      mixing_fraction,   &
+      gpt,               &
+      temperature_Planck
+   
+   integer :: i
+   integer :: did, vid
+   integer :: ierr, istat
+
+   character(32), dimension(:),  allocatable :: gas_names
+   integer,  dimension(:,:,:),   allocatable :: key_species
+   integer,  dimension(:,:),     allocatable :: band2gpt
+   real(r8), dimension(:,:),     allocatable :: band_lims_wavenum
+   real(r8), dimension(:),       allocatable :: press_ref, temp_ref
+   real(r8)                                  :: press_ref_trop, temp_ref_t, temp_ref_p
+   real(r8), dimension(:,:,:),   allocatable :: vmr_ref
+   real(r8), dimension(:,:,:,:), allocatable :: kmajor
+   real(r8), dimension(:,:,:),   allocatable :: kminor_lower, kminor_upper
+   real(r8), dimension(:,:),     allocatable :: totplnk
+   real(r8), dimension(:,:,:,:), allocatable :: planck_frac
+   real(r8), dimension(:),       allocatable :: solar_src_quiet, solar_src_facular, solar_src_sunspot
+   real(r8)                                  :: tsi_default
+   real(r8), dimension(:,:,:),   allocatable :: rayl_lower, rayl_upper
+   character(len=32), dimension(:),  allocatable :: gas_minor,         &
+                                                    identifier_minor,  &
+                                                    minor_gases_lower, &
+                                                    minor_gases_upper, &
+                                                    scaling_gas_lower, &
+                                                    scaling_gas_upper
+   integer, dimension(:,:),          allocatable :: minor_limits_gpt_lower, &
+                                                    minor_limits_gpt_upper
+   ! Send these to RRTMGP as logicals,
+   ! but they have to be read from the netCDF as integers
+   logical, dimension(:),            allocatable :: minor_scales_with_density_lower, &
+                                                    minor_scales_with_density_upper
+   logical, dimension(:),            allocatable :: scale_by_complement_lower, &
+                                                    scale_by_complement_upper
+   integer, dimension(:), allocatable :: int2log   ! use this to convert integer-to-logical.
+   integer, dimension(:),            allocatable :: kminor_start_lower, kminor_start_upper
+   real(r8), dimension(:,:),         allocatable :: optimal_angle_fit
+   real(r8)                                      :: mg_default, sb_default
+
+   integer :: pairs, &
+              minorabsorbers, &
+              minor_absorber_intervals_lower, &
+              minor_absorber_intervals_upper, &
+              contributors_lower, &
+              contributors_upper, &
+              fit_coeffs
+
+   character(len=128) :: error_msg
+   character(len=*), parameter :: sub = 'coefs_init'
+   !----------------------------------------------------------------------------
+
+   ! Open file
+   call getfil(coefs_file, locfn, 0)
+   call cam_pio_openfile(fh, locfn, PIO_NOWRITE)
+
+   call pio_seterrorhandling(fh, PIO_BCAST_ERROR)
+
+   ! Get dimensions
+
+   ierr = pio_inq_dimid(fh, 'absorber', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': absorber not found')
+   ierr = pio_inq_dimlen(fh, did, absorber)
+
+   ierr = pio_inq_dimid(fh, 'atmos_layer', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': atmos_layer not found')
+   ierr = pio_inq_dimlen(fh, did, atmos_layer)
+
+   ierr = pio_inq_dimid(fh, 'bnd', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': bnd not found')
+   ierr = pio_inq_dimlen(fh, did, bnd)
+
+   ierr = pio_inq_dimid(fh, 'pressure', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': pressure not found')
+   ierr = pio_inq_dimlen(fh, did, pressure)
+
+   ierr = pio_inq_dimid(fh, 'temperature', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': temperature not found')
+   ierr = pio_inq_dimlen(fh, did, temperature)
+
+   ierr = pio_inq_dimid(fh, 'absorber_ext', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': absorber_ext not found')
+   ierr = pio_inq_dimlen(fh, did, absorber_ext)
+
+   ierr = pio_inq_dimid(fh, 'pressure_interp', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': pressure_interp not found')
+   ierr = pio_inq_dimlen(fh, did, pressure_interp)
+
+   ierr = pio_inq_dimid(fh, 'mixing_fraction', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': mixing_fraction not found')
+   ierr = pio_inq_dimlen(fh, did, mixing_fraction)
+   
+   ierr = pio_inq_dimid(fh, 'gpt', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': gpt not found')
+   ierr = pio_inq_dimlen(fh, did, gpt)
+
+   temperature_Planck = 0
+   ierr = pio_inq_dimid(fh, 'temperature_Planck', did)
+   if (ierr == PIO_NOERR) then
+      ierr = pio_inq_dimlen(fh, did, temperature_Planck)
+   end if
+   ierr = pio_inq_dimid(fh, 'pair', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': pair not found')
+   ierr = pio_inq_dimlen(fh, did, pairs)
+   ierr = pio_inq_dimid(fh, 'minor_absorber', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_absorber not found')
+   ierr = pio_inq_dimlen(fh, did, minorabsorbers)
+   ierr = pio_inq_dimid(fh, 'minor_absorber_intervals_lower', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_absorber_intervals_lower not found')
+   ierr = pio_inq_dimlen(fh, did, minor_absorber_intervals_lower)
+   ierr = pio_inq_dimid(fh, 'minor_absorber_intervals_upper', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_absorber_intervals_upper not found')
+   ierr = pio_inq_dimlen(fh, did, minor_absorber_intervals_upper)
+   ierr = pio_inq_dimid(fh, 'contributors_lower', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': contributors_lower not found')
+   ierr = pio_inq_dimlen(fh, did, contributors_lower)
+   ierr = pio_inq_dimid(fh, 'contributors_upper', did)
+   if (ierr /= PIO_NOERR) call endrun(sub//': contributors_upper not found')
+   ierr = pio_inq_dimlen(fh, did, contributors_upper)
+
+   ierr = pio_inq_dimid(fh, 'fit_coeffs', did)
+   if (ierr == PIO_NOERR) then
+      ierr = pio_inq_dimlen(fh, did, fit_coeffs)
+   end if
+
+   ! Get variables
+   
+   ! names of absorbing gases
+   allocate(gas_names(absorber), stat=istat)
+   call handle_allocate_error(istat, sub, 'gas_names')
+   ierr = pio_inq_varid(fh, 'gas_names', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': gas_names not found')
+   ierr = pio_get_var(fh, vid, gas_names)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading gas_names')
+
+   ! key species pair for each band
+   allocate(key_species(2,atmos_layer,bnd), stat=istat)
+   call handle_allocate_error(istat, sub, 'key_species')
+   ierr = pio_inq_varid(fh, 'key_species', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': key_species not found')
+   ierr = pio_get_var(fh, vid, key_species)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading key_species')
+
+   ! beginning and ending gpoint for each band
+   allocate(band2gpt(2,bnd), stat=istat)
+   call handle_allocate_error(istat, sub, 'band2gpt')
+   ierr = pio_inq_varid(fh, 'bnd_limits_gpt', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': bnd_limits_gpt not found')
+   ierr = pio_get_var(fh, vid, band2gpt)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading bnd_limits_gpt')
+
+   ! beginning and ending wavenumber for each band
+   allocate(band_lims_wavenum(2,bnd), stat=istat)
+   call handle_allocate_error(istat, sub, 'band_lims_wavenum')
+   ierr = pio_inq_varid(fh, 'bnd_limits_wavenumber', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': bnd_limits_wavenumber not found')
+   ierr = pio_get_var(fh, vid, band_lims_wavenum)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading bnd_limits_wavenumber')
+
+   ! pressures [hPa] for reference atmosphere; press_ref(# reference layers)
+   allocate(press_ref(pressure), stat=istat)
+   call handle_allocate_error(istat, sub, 'press_ref')
+   ierr = pio_inq_varid(fh, 'press_ref', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': press_ref not found')
+   ierr = pio_get_var(fh, vid, press_ref)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading press_ref')
+
+   ! reference pressure separating the lower and upper atmosphere
+   ierr = pio_inq_varid(fh, 'press_ref_trop', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': press_ref_trop not found')
+   ierr = pio_get_var(fh, vid, press_ref_trop)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading press_ref_trop')
+
+   ! temperatures [K] for reference atmosphere; temp_ref(# reference layers)
+   allocate(temp_ref(temperature), stat=istat)
+   call handle_allocate_error(istat, sub, 'temp_ref')
+   ierr = pio_inq_varid(fh, 'temp_ref', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': temp_ref not found')
+   ierr = pio_get_var(fh, vid, temp_ref)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading temp_ref')
+
+   ! standard spectroscopic reference temperature [K]
+   ierr = pio_inq_varid(fh, 'absorption_coefficient_ref_T', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': absorption_coefficient_ref_T not found')
+   ierr = pio_get_var(fh, vid, temp_ref_t)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading absorption_coefficient_ref_T')
+
+   ! standard spectroscopic reference pressure [hPa]
+   ierr = pio_inq_varid(fh, 'absorption_coefficient_ref_P', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': absorption_coefficient_ref_P not found')
+   ierr = pio_get_var(fh, vid, temp_ref_p)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading absorption_coefficient_ref_P')
+
+   ! volume mixing ratios for reference atmosphere
+   allocate(vmr_ref(atmos_layer, absorber_ext, temperature), stat=istat)
+   call handle_allocate_error(istat, sub, 'vmr_ref')
+   ierr = pio_inq_varid(fh, 'vmr_ref', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': vmr_ref not found')
+   ierr = pio_get_var(fh, vid, vmr_ref)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading vmr_ref')
+
+   ! absorption coefficients due to major absorbing gases
+   allocate(kmajor(gpt,mixing_fraction,pressure_interp,temperature), stat=istat)
+   call handle_allocate_error(istat, sub, 'kmajor')
+   ierr = pio_inq_varid(fh, 'kmajor', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': kmajor not found')
+   ierr = pio_get_var(fh, vid, kmajor)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading kmajor')
+
+   ! absorption coefficients due to minor absorbing gases in lower part of atmosphere
+   allocate(kminor_lower(contributors_lower, mixing_fraction, temperature), stat=istat)
+   call handle_allocate_error(istat, sub, 'kminor_lower')
+   ierr = pio_inq_varid(fh, 'kminor_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': kminor_lower not found')
+   ierr = pio_get_var(fh, vid, kminor_lower)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading kminor_lower')
+
+   ! absorption coefficients due to minor absorbing gases in upper part of atmosphere
+   allocate(kminor_upper(contributors_upper, mixing_fraction, temperature), stat=istat)
+   call handle_allocate_error(istat, sub, 'kminor_upper')
+   ierr = pio_inq_varid(fh, 'kminor_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': kminor_upper not found')
+   ierr = pio_get_var(fh, vid, kminor_upper)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading kminor_upper')
+
+   ! integrated Planck function by band
+   ierr = pio_inq_varid(fh, 'totplnk', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(totplnk(temperature_Planck,bnd), stat=istat)
+      call handle_allocate_error(istat, sub, 'totplnk')
+      ierr = pio_get_var(fh, vid, totplnk)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading totplnk')
+   end if
+
+   ! Planck fractions
+   ierr = pio_inq_varid(fh, 'plank_fraction', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(planck_frac(gpt,mixing_fraction,pressure_interp,temperature), stat=istat)
+      call handle_allocate_error(istat, sub, 'planck_frac')
+      ierr = pio_get_var(fh, vid, planck_frac)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading plank_fraction')
+   end if
+
+   ierr = pio_inq_varid(fh, 'optimal_angle_fit', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(optimal_angle_fit(fit_coeffs, bnd), stat=istat)
+      call handle_allocate_error(istat, sub, 'optiman_angle_fit')
+      ierr = pio_get_var(fh, vid, optimal_angle_fit)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading optimal_angle_fit')
+   end if
+
+   ierr = pio_inq_varid(fh, 'solar_source_quiet', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(solar_src_quiet(gpt), stat=istat)
+      call handle_allocate_error(istat, sub, 'solar_src_quiet')
+      ierr = pio_get_var(fh, vid, solar_src_quiet)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading solar_source_quiet')
+   end if
+
+   ierr = pio_inq_varid(fh, 'solar_source_facular', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(solar_src_facular(gpt), stat=istat)
+      call handle_allocate_error(istat, sub, 'solar_src_facular')
+      ierr = pio_get_var(fh, vid, solar_src_facular)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading solar_source_facular')
+   end if
+
+   ierr = pio_inq_varid(fh, 'solar_source_sunspot', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(solar_src_sunspot(gpt), stat=istat)
+      call handle_allocate_error(istat, sub, 'solar_src_sunspot')
+      ierr = pio_get_var(fh, vid, solar_src_sunspot)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading solar_source_sunspot')
+   end if
+
+   ierr = pio_inq_varid(fh, 'tsi_default', vid)
+   if (ierr == PIO_NOERR) then
+      ierr = pio_get_var(fh, vid, tsi_default)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading tsi_default')
+   end if
+
+   ierr = pio_inq_varid(fh, 'mg_default', vid)
+   if (ierr == PIO_NOERR) then
+      ierr = pio_get_var(fh, vid, mg_default)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading mg_default')
+   end if
+
+   ierr = pio_inq_varid(fh, 'sb_default', vid)
+   if (ierr == PIO_NOERR) then
+      ierr = pio_get_var(fh, vid, sb_default)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading sb_default')
+   end if
+
+   ! rayleigh scattering contribution in lower part of atmosphere
+   ierr = pio_inq_varid(fh, 'rayl_lower', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(rayl_lower(gpt,mixing_fraction,temperature), stat=istat)
+      call handle_allocate_error(istat, sub, 'rayl_lower')
+      ierr = pio_get_var(fh, vid, rayl_lower)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading rayl_lower')
+   end if
+
+   ! rayleigh scattering contribution in upper part of atmosphere
+   ierr = pio_inq_varid(fh, 'rayl_upper', vid)
+   if (ierr == PIO_NOERR) then
+      allocate(rayl_upper(gpt,mixing_fraction,temperature), stat=istat)
+      call handle_allocate_error(istat, sub, 'rayl_upper')
+      ierr = pio_get_var(fh, vid, rayl_upper)
+      if (ierr /= PIO_NOERR) call endrun(sub//': error reading rayl_upper')
+   end if
+
+   allocate(gas_minor(minorabsorbers), stat=istat)
+   call handle_allocate_error(istat, sub, 'gas_minor')
+   ierr = pio_inq_varid(fh, 'gas_minor', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': gas_minor not found')
+   ierr = pio_get_var(fh, vid, gas_minor)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading gas_minor')
+
+   allocate(identifier_minor(minorabsorbers), stat=istat)
+   call handle_allocate_error(istat, sub, 'identifier_minor')
+   ierr = pio_inq_varid(fh, 'identifier_minor', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': identifier_minor not found')
+   ierr = pio_get_var(fh, vid, identifier_minor)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading identifier_minor')
+   
+   allocate(minor_gases_lower(minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'minor_gases_lower')
+   ierr = pio_inq_varid(fh, 'minor_gases_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_gases_lower not found')
+   ierr = pio_get_var(fh, vid, minor_gases_lower)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading minor_gases_lower')
+
+   allocate(minor_gases_upper(minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'minor_gases_upper')
+   ierr = pio_inq_varid(fh, 'minor_gases_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_gases_upper not found')
+   ierr = pio_get_var(fh, vid, minor_gases_upper)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading minor_gases_upper')
+
+   allocate(minor_limits_gpt_lower(pairs,minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'minor_limits_gpt_lower')
+   ierr = pio_inq_varid(fh, 'minor_limits_gpt_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_limits_gpt_lower not found')
+   ierr = pio_get_var(fh, vid, minor_limits_gpt_lower)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading minor_limits_gpt_lower')
+
+   allocate(minor_limits_gpt_upper(pairs,minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'minor_limits_gpt_upper')
+   ierr = pio_inq_varid(fh, 'minor_limits_gpt_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_limits_gpt_upper not found')
+   ierr = pio_get_var(fh, vid, minor_limits_gpt_upper)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading minor_limits_gpt_upper')
+
+   ! Read as integer and convert to logical
+   allocate(int2log(minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'int2log for lower')
+
+   allocate(minor_scales_with_density_lower(minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'minor_scales_with_density_lower')
+   ierr = pio_inq_varid(fh, 'minor_scales_with_density_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_scales_with_density_lower not found')
+   ierr = pio_get_var(fh, vid, int2log)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading minor_scales_with_density_lower')
+   do i = 1,minor_absorber_intervals_lower
+      if (int2log(i) .eq. 0) then
+         minor_scales_with_density_lower(i) = .false.
+      else
+         minor_scales_with_density_lower(i) = .true.
+      end if
+   end do
+
+   allocate(scale_by_complement_lower(minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'scale_by_complement_lower')
+   ierr = pio_inq_varid(fh, 'scale_by_complement_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': scale_by_complement_lower not found')
+   ierr = pio_get_var(fh, vid, int2log)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading scale_by_complement_lower')
+   do i = 1,minor_absorber_intervals_lower
+      if (int2log(i) .eq. 0) then
+         scale_by_complement_lower(i) = .false.
+      else
+         scale_by_complement_lower(i) = .true.
+      end if
+   end do
+
+   deallocate(int2log)
+
+   ! Read as integer and convert to logical
+   allocate(int2log(minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'int2log for upper')
+
+   allocate(minor_scales_with_density_upper(minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'minor_scales_with_density_upper')
+   ierr = pio_inq_varid(fh, 'minor_scales_with_density_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': minor_scales_with_density_upper not found')
+   ierr = pio_get_var(fh, vid, int2log)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading minor_scales_with_density_upper')
+   do i = 1,minor_absorber_intervals_upper
+      if (int2log(i) .eq. 0) then
+         minor_scales_with_density_upper(i) = .false.
+      else
+         minor_scales_with_density_upper(i) = .true.
+      end if
+   end do
+
+   allocate(scale_by_complement_upper(minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'scale_by_complement_upper')
+   ierr = pio_inq_varid(fh, 'scale_by_complement_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': scale_by_complement_upper not found')
+   ierr = pio_get_var(fh, vid, int2log)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading scale_by_complement_upper')
+   do i = 1,minor_absorber_intervals_upper
+      if (int2log(i) .eq. 0) then
+         scale_by_complement_upper(i) = .false.
+      else
+         scale_by_complement_upper(i) = .true.
+      end if
+   end do
+
+   deallocate(int2log)
+
+   allocate(scaling_gas_lower(minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'scaling_gas_lower')
+   ierr = pio_inq_varid(fh, 'scaling_gas_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': scaling_gas_lower not found')
+   ierr = pio_get_var(fh, vid, scaling_gas_lower)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading scaling_gas_lower')
+
+   allocate(scaling_gas_upper(minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'scaling_gas_upper')
+   ierr = pio_inq_varid(fh, 'scaling_gas_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': scaling_gas_upper not found')
+   ierr = pio_get_var(fh, vid, scaling_gas_upper)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading scaling_gas_upper')
+
+   allocate(kminor_start_lower(minor_absorber_intervals_lower), stat=istat)
+   call handle_allocate_error(istat, sub, 'kminor_start_lower')
+   ierr = pio_inq_varid(fh, 'kminor_start_lower', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': kminor_start_lower not found')
+   ierr = pio_get_var(fh, vid, kminor_start_lower)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading kminor_start_lower')
+
+   allocate(kminor_start_upper(minor_absorber_intervals_upper), stat=istat)
+   call handle_allocate_error(istat, sub, 'kminor_start_upper')
+   ierr = pio_inq_varid(fh, 'kminor_start_upper', vid)
+   if (ierr /= PIO_NOERR) call endrun(sub//': kminor_start_upper not found')
+   ierr = pio_get_var(fh, vid, kminor_start_upper)
+   if (ierr /= PIO_NOERR) call endrun(sub//': error reading kminor_start_upper')
+
+   ! Close file
+   call pio_closefile(fh)
+
+   ! Initialize the gas optics object with data. The calls are slightly different depending
+   ! on whether the radiation sources are internal to the atmosphere (longwave) or external (shortwave)
+
+   if (allocated(totplnk) .and. allocated(planck_frac)) then
+      error_msg = kdist%load( &
+         available_gases, gas_names, key_species,              &
+         band2gpt, band_lims_wavenum,                          &
+         press_ref, press_ref_trop, temp_ref,                  &
+         temp_ref_p, temp_ref_t, vmr_ref,                      &
+         kmajor, kminor_lower, kminor_upper,                   &
+         gas_minor, identifier_minor,                          &
+         minor_gases_lower, minor_gases_upper,                 &
+         minor_limits_gpt_lower, minor_limits_gpt_upper,       &
+         minor_scales_with_density_lower,                      &
+         minor_scales_with_density_upper,                      &
+         scaling_gas_lower, scaling_gas_upper,                 &
+         scale_by_complement_lower, scale_by_complement_upper, &
+         kminor_start_lower, kminor_start_upper,               &
+         totplnk, planck_frac, rayl_lower, rayl_upper,         &
+         optimal_angle_fit)
+   else if (allocated(solar_src_quiet)) then
+      error_msg = kdist%load( &
+         available_gases, gas_names, key_species,               &
+         band2gpt, band_lims_wavenum,                           &
+         press_ref, press_ref_trop, temp_ref,                   &
+         temp_ref_p, temp_ref_t, vmr_ref,                       & 
+         kmajor, kminor_lower, kminor_upper,                    &
+         gas_minor, identifier_minor,                           &
+         minor_gases_lower, minor_gases_upper,                  &
+         minor_limits_gpt_lower, minor_limits_gpt_upper,        &
+         minor_scales_with_density_lower,                       &
+         minor_scales_with_density_upper,                       &
+         scaling_gas_lower, scaling_gas_upper,                  &
+         scale_by_complement_lower,                             &
+         scale_by_complement_upper,                             &
+         kminor_start_lower,                                    &
+         kminor_start_upper,                                    &
+         solar_src_quiet, solar_src_facular, solar_src_sunspot, &
+         tsi_default, mg_default, sb_default,                   &
+         rayl_lower, rayl_upper)
+   else
+      error_msg = 'must supply either totplnk and planck_frac, or solar_src_[*]'
+   end if
+
+   call stop_on_err(error_msg, sub, 'kdist%load')
+
+   deallocate( &
+      gas_names, key_species,               &
+      band2gpt, band_lims_wavenum,          &
+      press_ref, temp_ref, vmr_ref,         &
+      kmajor, kminor_lower, kminor_upper,   &
+      gas_minor, identifier_minor,          &
+      minor_gases_lower, minor_gases_upper, &
+      minor_limits_gpt_lower,               & 
+      minor_limits_gpt_upper,               &
+      minor_scales_with_density_lower,      &
+      minor_scales_with_density_upper,      &
+      scale_by_complement_lower,            & 
+      scale_by_complement_upper,            &
+      scaling_gas_lower, scaling_gas_upper, & 
+      kminor_start_lower, kminor_start_upper)
+
+   if (allocated(totplnk))           deallocate(totplnk)
+   if (allocated(planck_frac))       deallocate(planck_frac)
+   if (allocated(optimal_angle_fit)) deallocate(optimal_angle_fit)
+   if (allocated(solar_src_quiet))   deallocate(solar_src_quiet)
+   if (allocated(solar_src_facular)) deallocate(solar_src_facular)
+   if (allocated(solar_src_sunspot)) deallocate(solar_src_sunspot)
+   if (allocated(rayl_lower))        deallocate(rayl_lower)
+   if (allocated(rayl_upper))        deallocate(rayl_upper)
+
+end subroutine coefs_init
+
+!=========================================================================================
+
+subroutine initialize_rrtmgp_fluxes(ncol, nlevels, nbands, fluxes, do_direct)
+
+   ! Allocate flux arrays and set values to zero.
+
+   ! Arguments
+   integer,                    intent(in)    :: ncol, nlevels, nbands
+   class(ty_fluxes_broadband), intent(inout) :: fluxes
+   logical, optional,          intent(in)    :: do_direct
+
+   ! Local variables
+   logical :: do_direct_local
+   integer :: istat
+   character(len=*), parameter :: sub = 'initialize_rrtmgp_fluxes'
+   !----------------------------------------------------------------------------
+
+   if (present(do_direct)) then
+      do_direct_local = .true.
+   else
+      do_direct_local = .false.
+   end if
+
+   ! Broadband fluxes
+   allocate(fluxes%flux_up(ncol, nlevels), stat=istat)
+   call handle_allocate_error(istat, sub, 'fluxes%flux_up')
+   allocate(fluxes%flux_dn(ncol, nlevels), stat=istat)
+   call handle_allocate_error(istat, sub, 'fluxes%flux_dn')
+   allocate(fluxes%flux_net(ncol, nlevels), stat=istat)
+   call handle_allocate_error(istat, sub, 'fluxes%flux_net')
+   if (do_direct_local) then
+      allocate(fluxes%flux_dn_dir(ncol, nlevels), stat=istat)
+      call handle_allocate_error(istat, sub, 'fluxes%flux_dn_dir')
+   end if
+
+   select type (fluxes)
+   type is (ty_fluxes_byband)
+      ! Fluxes by band always needed for SW.  Only allocate for LW
+      ! when spectralflux is true.
+      if (nbands == nswbands .or. spectralflux) then
+         allocate(fluxes%bnd_flux_up(ncol, nlevels, nbands), stat=istat)
+         call handle_allocate_error(istat, sub, 'fluxes%bnd_flux_up')
+         allocate(fluxes%bnd_flux_dn(ncol, nlevels, nbands), stat=istat)
+         call handle_allocate_error(istat, sub, 'fluxes%bnd_flux_dn')
+         allocate(fluxes%bnd_flux_net(ncol, nlevels, nbands), stat=istat)
+         call handle_allocate_error(istat, sub, 'fluxes%bnd_flux_net')
+         if (do_direct_local) then
+            allocate(fluxes%bnd_flux_dn_dir(ncol, nlevels, nbands), stat=istat)
+            call handle_allocate_error(istat, sub, 'fluxes%bnd_flux_dn_dir')
+         end if
+      end if
+   end select
+
+   ! Initialize
+   call reset_fluxes(fluxes)
+
+end subroutine initialize_rrtmgp_fluxes
+
+!=========================================================================================
+
+subroutine reset_fluxes(fluxes)
+
+   ! Reset flux arrays to zero.
+
+   class(ty_fluxes_broadband), intent(inout) :: fluxes
+   !----------------------------------------------------------------------------
+
+   ! Reset broadband fluxes
+   fluxes%flux_up(:,:) = 0._r8
+   fluxes%flux_dn(:,:) = 0._r8
+   fluxes%flux_net(:,:) = 0._r8
+   if (associated(fluxes%flux_dn_dir)) fluxes%flux_dn_dir(:,:) = 0._r8
+
+   select type (fluxes)
+   type is (ty_fluxes_byband)
+      ! Reset band-by-band fluxes
+      if (associated(fluxes%bnd_flux_up)) fluxes%bnd_flux_up(:,:,:) = 0._r8
+      if (associated(fluxes%bnd_flux_dn)) fluxes%bnd_flux_dn(:,:,:) = 0._r8
+      if (associated(fluxes%bnd_flux_net)) fluxes%bnd_flux_net(:,:,:) = 0._r8
+      if (associated(fluxes%bnd_flux_dn_dir)) fluxes%bnd_flux_dn_dir(:,:,:) = 0._r8
+   end select
+
+end subroutine reset_fluxes
+
+!=========================================================================================
+
+subroutine free_optics_sw(optics)
+
+   type(ty_optical_props_2str), intent(inout) :: optics
+
+   if (allocated(optics%tau)) deallocate(optics%tau)
+   if (allocated(optics%ssa)) deallocate(optics%ssa)
+   if (allocated(optics%g)) deallocate(optics%g)
+   call optics%finalize()
+
+end subroutine free_optics_sw
+
+!=========================================================================================
+
+subroutine free_optics_lw(optics)
+
+   type(ty_optical_props_1scl), intent(inout) :: optics
+
+   if (allocated(optics%tau)) deallocate(optics%tau)
+   call optics%finalize()
+
+end subroutine free_optics_lw
+
+!=========================================================================================
+
+subroutine free_fluxes(fluxes)
+
+   class(ty_fluxes_broadband), intent(inout) :: fluxes
+
+   if (associated(fluxes%flux_up)) deallocate(fluxes%flux_up)
+   if (associated(fluxes%flux_dn)) deallocate(fluxes%flux_dn)
+   if (associated(fluxes%flux_net)) deallocate(fluxes%flux_net)
+   if (associated(fluxes%flux_dn_dir)) deallocate(fluxes%flux_dn_dir)
+
+   select type (fluxes)
+   type is (ty_fluxes_byband)
+      if (associated(fluxes%bnd_flux_up)) deallocate(fluxes%bnd_flux_up)
+      if (associated(fluxes%bnd_flux_dn)) deallocate(fluxes%bnd_flux_dn)
+      if (associated(fluxes%bnd_flux_net)) deallocate(fluxes%bnd_flux_net)
+      if (associated(fluxes%bnd_flux_dn_dir)) deallocate(fluxes%bnd_flux_dn_dir)
+   end select
+
+end subroutine free_fluxes
+
+!=========================================================================================
+
+subroutine modified_cloud_fraction(ncol, cld, cldfsnow, cldfgrau, cldfprime)
+
+   ! Compute modified cloud fraction, cldfprime.
+   ! 1. initialize as cld
+   ! 2. modify for snow if cldfsnow is available. use max(cld, cldfsnow)
+   ! 3. modify for graupel if cldfgrau is available and graupel_in_rad is true.
+   !    use max(cldfprime, cldfgrau)
+
+   ! Arguments
+   integer,  intent(in)  :: ncol
+   real(r8), pointer     :: cld(:,:)       ! cloud fraction
+   real(r8), pointer     :: cldfsnow(:,:)  ! cloud fraction of just "snow clouds"
+   real(r8), pointer     :: cldfgrau(:,:)  ! cloud fraction of just "graupel clouds"
+   real(r8), intent(out) :: cldfprime(:,:) ! modified cloud fraction
+
+   ! Local variables
+   integer :: i, k
+   !----------------------------------------------------------------------------
+
+   if (associated(cldfsnow)) then
+      do k = 1, pver
+         do i = 1, ncol
+            cldfprime(i,k) = max(cld(i,k), cldfsnow(i,k))
+         end do
+      end do
+   else
+      cldfprime(:ncol,:) = cld(:ncol,:)
+   end if
+
+   if (associated(cldfgrau) .and. graupel_in_rad) then
+      do k = 1, pver
+         do i = 1, ncol
+            cldfprime(i,k) = max(cldfprime(i,k), cldfgrau(i,k))
+         end do
+      end do
+   end if
+
+end subroutine modified_cloud_fraction
+
+!=========================================================================================
+
+subroutine stop_on_err(errmsg, sub, info)
+
+! call endrun if RRTMGP function returns non-empty error message.
+
+   character(len=*), intent(in) :: errmsg    ! return message from RRTMGP function
+   character(len=*), intent(in) :: sub       ! name of calling subroutine
+   character(len=*), intent(in) :: info      ! name of called function
+
+   if (len_trim(errmsg) > 0) then
+      call endrun(trim(sub)//': ERROR: '//trim(info)//': '//trim(errmsg))
+   end if
+
+end subroutine stop_on_err
+
+!=========================================================================================
+
+end module radiation
+
diff --git a/src/physics/rrtmgp/rrtmgp_inputs.F90 b/src/physics/rrtmgp/rrtmgp_inputs.F90
new file mode 100644
index 0000000000..2f2b125e09
--- /dev/null
+++ b/src/physics/rrtmgp/rrtmgp_inputs.F90
@@ -0,0 +1,1003 @@
+module rrtmgp_inputs
+
+!--------------------------------------------------------------------------------
+! Transform data for inputs from CAM's data structures to those used by
+! RRTMGP.  Subset the number of model levels if CAM's top exceeds RRTMGP's
+! valid domain.  Add an extra layer if CAM's top is below 1 Pa.
+! The vertical indexing increases from top to bottom of atmosphere in both
+! CAM and RRTMGP arrays.   
+!--------------------------------------------------------------------------------
+
+use shr_kind_mod,     only: r8=>shr_kind_r8
+use ppgrid,           only: pcols, pver, pverp
+
+use physconst,        only: stebol, pi
+
+use physics_types,    only: physics_state
+use physics_buffer,   only: physics_buffer_desc
+use camsrfexch,       only: cam_in_t
+
+use radconstants,     only: nradgas, gaslist, nswbands, nlwbands, nswgpts, nlwgpts,   &
+                            get_sw_spectral_boundaries, idx_sw_diag, idx_sw_cloudsim, &
+                            idx_lw_cloudsim
+
+use rad_constituents, only: rad_cnst_get_gas
+
+use cloud_rad_props,  only: get_liquid_optics_sw, liquid_cloud_get_rad_props_lw, &
+                            get_ice_optics_sw,    ice_cloud_get_rad_props_lw,    &
+                            get_snow_optics_sw,   snow_cloud_get_rad_props_lw,   &
+                            get_grau_optics_sw,   grau_cloud_get_rad_props_lw
+                                 
+use mcica_subcol_gen, only: mcica_subcol_sw, mcica_subcol_lw
+
+use aer_rad_props,    only: aer_rad_props_sw, aer_rad_props_lw
+
+use mo_gas_concentrations, only: ty_gas_concs
+use mo_gas_optics_rrtmgp,  only: ty_gas_optics_rrtmgp 
+use mo_optical_props,      only: ty_optical_props_2str, ty_optical_props_1scl
+
+use cam_history_support,   only: fillvalue
+use cam_logfile,      only: iulog
+use cam_abortutils,   only: endrun
+use error_messages,   only: alloc_err
+
+implicit none
+private
+save
+
+public :: &
+   rrtmgp_inputs_init,  &
+   rrtmgp_set_state,    &
+   rrtmgp_set_gases_lw, &
+   rrtmgp_set_gases_sw, &
+   rrtmgp_set_cloud_lw, &
+   rrtmgp_set_cloud_sw, &
+   rrtmgp_set_aer_lw,   &
+   rrtmgp_set_aer_sw
+
+
+! This value is to match the arbitrary small value used in RRTMG to decide
+! when a quantity is effectively zero.
+real(r8), parameter :: tiny = 1.0e-80_r8
+
+! Indices for copying data between cam and rrtmgp arrays
+integer :: ktopcam ! Index in CAM arrays of top level (layer or interface) at which
+                   ! RRTMGP is active.
+integer :: ktoprad ! Index in RRTMGP arrays of the layer or interface corresponding
+                   ! to CAM's top layer or interface
+
+! wavenumber (cm^-1) boundaries of shortwave bands
+real(r8) :: sw_low_bounds(nswbands), sw_high_bounds(nswbands)
+
+! Mapping from RRTMG shortwave bands to RRTMGP.  Currently needed to continue using
+! the SW optics datasets from RRTMG (even thought there is a slight mismatch in the
+! band boundaries of the 2 bands that overlap with the LW bands).
+integer, parameter, dimension(14) :: rrtmg_to_rrtmgp_swbands = &
+   [ 14, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 ]
+
+!==================================================================================================
+contains
+!==================================================================================================
+
+subroutine rrtmgp_inputs_init(ktcam, ktrad)
+      
+   ! Note that this routine must be called after the calls to set_wavenumber_bands which set
+   ! the sw/lw band boundaries in the radconstants module.
+
+   integer, intent(in) :: ktcam
+   integer, intent(in) :: ktrad
+
+   ktopcam = ktcam
+   ktoprad = ktrad
+
+   ! Initialize the module data containing the SW band boundaries.
+   call get_sw_spectral_boundaries(sw_low_bounds, sw_high_bounds, 'cm^-1')
+
+end subroutine rrtmgp_inputs_init
+
+!=========================================================================================
+
+subroutine rrtmgp_set_state( &
+   state, cam_in, ncol, nlay, nday,           &
+   idxday, coszrs, kdist_sw, t_sfc, emis_sfc,  &
+   t_rad, pmid_rad, pint_rad, t_day, pmid_day, &
+   pint_day, coszrs_day, alb_dir, alb_dif) 
+
+   ! arguments
+   type(physics_state),         intent(in) :: state     ! CAM physics state
+   type(cam_in_t),              intent(in) :: cam_in    ! CAM import state
+   integer,                     intent(in) :: ncol      ! # cols in CAM chunk
+   integer,                     intent(in) :: nlay      ! # layers in rrtmgp grid
+   integer,                     intent(in) :: nday      ! # daylight columns
+   integer,                     intent(in) :: idxday(:) ! chunk indicies of daylight columns
+   real(r8),                    intent(in) :: coszrs(:) ! cosine of solar zenith angle
+   class(ty_gas_optics_rrtmgp), intent(in) :: kdist_sw  ! spectral information
+
+   real(r8), intent(out) :: t_sfc(ncol)              ! surface temperature [K] 
+   real(r8), intent(out) :: emis_sfc(nlwbands,ncol)  ! emissivity at surface []
+   real(r8), intent(out) :: t_rad(ncol,nlay)         ! layer midpoint temperatures [K]
+   real(r8), intent(out) :: pmid_rad(ncol,nlay)      ! layer midpoint pressures [Pa]
+   real(r8), intent(out) :: pint_rad(ncol,nlay+1)    ! layer interface pressures [Pa]
+   real(r8), intent(out) :: t_day(nday,nlay)         ! layer midpoint temperatures [K]
+   real(r8), intent(out) :: pmid_day(nday,nlay)      ! layer midpoint pressure [Pa]
+   real(r8), intent(out) :: pint_day(nday,nlay+1)    ! layer interface pressures [Pa]
+   real(r8), intent(out) :: coszrs_day(nday)         ! cosine of solar zenith angle
+   real(r8), intent(out) :: alb_dir(nswbands,nday)   ! surface albedo, direct radiation
+   real(r8), intent(out) :: alb_dif(nswbands,nday)   ! surface albedo, diffuse radiation
+
+   ! local variables
+   integer :: i, k, iband
+
+   real(r8) :: tref_min, tref_max
+
+   character(len=*), parameter :: sub='rrtmgp_set_state'
+   character(len=512) :: errmsg
+   !--------------------------------------------------------------------------------
+
+   t_sfc = sqrt(sqrt(cam_in%lwup(:ncol)/stebol))  ! Surface temp set based on longwave up flux.
+
+   ! Set surface emissivity to 1.0.
+   ! The land model *does* have its own surface emissivity, but is not spectrally resolved.
+   ! The LW upward flux is calculated with that land emissivity, and the "radiative temperature"
+   ! t_sfc is derived from that flux. We assume, therefore, that the emissivity is unity
+   ! to be consistent with t_sfc.
+   emis_sfc(:,:) = 1._r8
+
+   ! Level ordering is the same for both CAM and RRTMGP (top to bottom)
+   t_rad(:,ktoprad:) = state%t(:ncol,ktopcam:)
+   pmid_rad(:,ktoprad:) = state%pmid(:ncol,ktopcam:)
+   pint_rad(:,ktoprad:) = state%pint(:ncol,ktopcam:)
+
+   ! Add extra layer values if needed.
+   if (nlay == pverp) then
+      t_rad(:,1)      = state%t(:ncol,1)
+      pmid_rad(:,1)   = 0.5_r8 * state%pint(:ncol,1)
+      ! The top reference pressure from the RRTMGP coefficients datasets is 1.005183574463 Pa
+      ! Set the top of the extra layer just below that.
+      pint_rad(:,1) = 1.01_r8
+   else
+      ! nlay < pverp, thus the 1 Pa level is within a CAM layer.  Assuming the top interface of
+      ! this layer is at a pressure < 1 Pa, we need to adjust the top of this layer so that it
+      ! is within the valid pressure range of RRTMGP (otherwise RRTMGP issues an error).  Then
+      ! set the midpoint pressure halfway between the interfaces.
+      pint_rad(:,1) = 1.01_r8
+      pmid_rad(:,1) = 0.5_r8 * (pint_rad(:,1) + pint_rad(:,2))
+   end if
+
+   ! Limit temperatures to be within the limits of RRTMGP validity.
+   tref_min = kdist_sw%get_temp_min()
+   tref_max = kdist_sw%get_temp_max()
+   t_rad = merge(t_rad, tref_min, t_rad > tref_min)
+   t_rad = merge(t_rad, tref_max, t_rad < tref_max)
+
+   ! Construct arrays containing only daylight columns
+   do i = 1, nday
+      t_day(i,:)    = t_rad(idxday(i),:)
+      pmid_day(i,:) = pmid_rad(idxday(i),:)
+      pint_day(i,:) = pint_rad(idxday(i),:)
+      coszrs_day(i) = coszrs(idxday(i))
+   end do
+ 
+   ! Assign albedos to the daylight columns (from E3SM implementation)
+   ! Albedos are imported from the surface models as broadband (visible, and near-IR),
+   ! and we need to map these to appropriate narrower bands used in RRTMGP. Bands
+   ! are categorized broadly as "visible/UV" or "infrared" based on wavenumber.
+   ! Loop over bands, and determine for each band whether it is broadly in the
+   ! visible or infrared part of the spectrum based on a dividing line of
+   ! 0.7 micron, or 14286 cm^-1
+   do iband = 1,nswbands
+      if (is_visible(sw_low_bounds(iband)) .and. &
+         is_visible(sw_high_bounds(iband))) then
+
+         ! Entire band is in the visible
+         do i = 1, nday
+            alb_dir(iband,i) = cam_in%asdir(idxday(i))
+            alb_dif(iband,i) = cam_in%asdif(idxday(i))
+         end do
+
+      else if (.not.is_visible(sw_low_bounds(iband)) .and. &
+               .not.is_visible(sw_high_bounds(iband))) then
+         ! Entire band is in the longwave (near-infrared)
+         do i = 1, nday
+            alb_dir(iband,i) = cam_in%aldir(idxday(i))
+            alb_dif(iband,i) = cam_in%aldif(idxday(i))
+         end do
+      else
+         ! Band straddles the visible to near-infrared transition, so we take
+         ! the albedo to be the average of the visible and near-infrared
+         ! broadband albedos
+         do i = 1, nday
+            alb_dir(iband,i) = 0.5_r8 * (cam_in%aldir(idxday(i)) + cam_in%asdir(idxday(i)))
+            alb_dif(iband,i) = 0.5_r8 * (cam_in%aldif(idxday(i)) + cam_in%asdif(idxday(i)))
+         end do
+      end if
+   end do
+
+   ! Strictly enforce albedo bounds
+   where (alb_dir < 0)
+       alb_dir = 0.0_r8
+   end where
+   where (alb_dir > 1)
+       alb_dir = 1.0_r8
+   end where
+   where (alb_dif < 0)
+       alb_dif = 0.0_r8
+   end where
+   where (alb_dif > 1)
+       alb_dif = 1.0_r8
+   end where
+
+end subroutine rrtmgp_set_state
+
+!=========================================================================================
+
+pure logical function is_visible(wavenumber)
+
+   ! Wavenumber is in the visible if it is above the visible threshold
+   ! wavenumber, and in the infrared if it is below the threshold
+   ! This function doesn't distinquish between visible and UV.
+
+   ! wavenumber in inverse cm (cm^-1)
+   real(r8), intent(in) :: wavenumber
+
+   ! Set threshold between visible and infrared to 0.7 micron, or 14286 cm^-1
+   real(r8), parameter :: visible_wavenumber_threshold = 14286._r8  ! cm^-1
+
+   if (wavenumber > visible_wavenumber_threshold) then
+      is_visible = .true.
+   else
+      is_visible = .false.
+   end if
+
+end function is_visible
+
+!=========================================================================================
+
+function get_molar_mass_ratio(gas_name) result(massratio)
+
+   ! return the molar mass ratio of dry air to gas based on gas_name
+
+   character(len=*),intent(in) :: gas_name
+   real(r8)                    :: massratio
+
+   ! local variables
+   real(r8), parameter :: amdw = 1.607793_r8    ! Molecular weight of dry air / water vapor
+   real(r8), parameter :: amdc = 0.658114_r8    ! Molecular weight of dry air / carbon dioxide
+   real(r8), parameter :: amdo = 0.603428_r8    ! Molecular weight of dry air / ozone
+   real(r8), parameter :: amdm = 1.805423_r8    ! Molecular weight of dry air / methane
+   real(r8), parameter :: amdn = 0.658090_r8    ! Molecular weight of dry air / nitrous oxide
+   real(r8), parameter :: amdo2 = 0.905140_r8   ! Molecular weight of dry air / oxygen
+   real(r8), parameter :: amdc1 = 0.210852_r8   ! Molecular weight of dry air / CFC11
+   real(r8), parameter :: amdc2 = 0.239546_r8   ! Molecular weight of dry air / CFC12
+
+   character(len=*), parameter :: sub='get_molar_mass_ratio'
+   !----------------------------------------------------------------------------
+
+   select case (trim(gas_name)) 
+      case ('H2O') 
+         massratio = amdw
+      case ('CO2')
+         massratio = amdc
+      case ('O3')
+         massratio = amdo
+      case ('CH4')
+         massratio = amdm
+      case ('N2O')
+         massratio = amdn
+      case ('O2')
+         massratio = amdo2
+      case ('CFC11')
+         massratio = amdc1
+      case ('CFC12')
+         massratio = amdc2
+      case default
+         call endrun(sub//": Invalid gas: "//trim(gas_name))
+   end select
+
+end function get_molar_mass_ratio
+
+!=========================================================================================
+
+subroutine rad_gas_get_vmr(icall, gas_name, state, pbuf, nlay, numactivecols, gas_concs, idxday)
+
+   ! Set volume mixing ratio in gas_concs object.
+   ! The gas_concs%set_vmr method copies data into internally allocated storage.
+
+   integer,                     intent(in) :: icall      ! index of climate/diagnostic radiation call
+   character(len=*),            intent(in) :: gas_name
+   type(physics_state), target, intent(in) :: state
+   type(physics_buffer_desc),   pointer    :: pbuf(:)
+   integer,                     intent(in) :: nlay           ! number of layers in radiation calculation
+   integer,                     intent(in) :: numactivecols  ! number of columns, ncol for LW, nday for SW
+
+   type(ty_gas_concs),       intent(inout) :: gas_concs  ! the result is VRM inside gas_concs
+
+   integer, optional,          intent(in) :: idxday(:)   ! indices of daylight columns in a chunk
+
+   ! Local variables
+   integer :: i, idx(numactivecols)
+   integer :: istat
+   real(r8), pointer     :: gas_mmr(:,:)
+   real(r8), allocatable :: gas_vmr(:,:)
+   real(r8), allocatable :: mmr(:,:)
+   real(r8) :: massratio
+
+   ! For ozone profile above model
+   real(r8) :: P_top, P_int, P_mid, alpha, beta, a, b, chi_mid, chi_0, chi_eff
+
+   character(len=128)          :: errmsg
+   character(len=*), parameter :: sub = 'rad_gas_get_vmr'
+   !----------------------------------------------------------------------------
+
+   ! set the column indices; when idxday is provided (e.g. daylit columns) use them, otherwise just count.
+   do i = 1, numactivecols
+      if (present(idxday)) then
+         idx(i) = idxday(i)
+      else
+         idx(i) = i
+      end if
+   end do
+
+   ! gas_mmr points to a "chunk" in either the state or pbuf objects.  That storage is
+   ! dimensioned (pcols,pver).
+   call rad_cnst_get_gas(icall, gas_name, state, pbuf, gas_mmr)
+
+   ! Copy into storage for RRTMGP
+   allocate(mmr(numactivecols, nlay), stat=istat)
+   call alloc_err(istat, sub, 'mmr', numactivecols*nlay)
+   allocate(gas_vmr(numactivecols, nlay), stat=istat)
+   call alloc_err(istat, sub, 'gas_vmr', numactivecols*nlay)
+
+   do i = 1, numactivecols
+      mmr(i,ktoprad:) = gas_mmr(idx(i),ktopcam:)
+   end do
+
+   ! If an extra layer is being used, copy mmr from the top layer of CAM to the extra layer.
+   if (nlay == pverp) then
+      mmr(:,1) = mmr(:,2)
+   end if
+
+   ! special case: H2O is specific humidity, not mixing ratio. Use r = q/(1-q):
+   if (gas_name == 'H2O') then 
+      mmr = mmr / (1._r8 - mmr)
+   end if  
+
+   ! convert MMR to VMR, multipy by ratio of dry air molar mas to gas molar mass.
+   massratio = get_molar_mass_ratio(gas_name)
+   gas_vmr = mmr * massratio
+
+   ! special case: Setting O3 in the extra layer:
+   ! 
+   ! For the purpose of attenuating solar fluxes above the CAM model top, we assume that ozone 
+   ! mixing decreases linearly in each column from the value in the top layer of CAM to zero at 
+   ! the pressure level set by P_top. P_top has been set to 50 Pa (0.5 hPa) based on model tuning 
+   ! to produce temperatures at the top of CAM that are most consistent with WACCM at similar pressure levels. 
+
+   if ((gas_name == 'O3') .and. (nlay == pverp)) then
+      P_top = 50.0_r8
+      do i = 1, numactivecols
+            P_int = state%pint(idx(i),1) ! pressure (Pa) at upper interface of CAM
+            P_mid = state%pmid(idx(i),1) ! pressure (Pa) at midpoint of top layer of CAM
+            alpha = log(P_int/P_top)
+            beta =  log(P_mid/P_int)/log(P_mid/P_top)
+      
+            a =  ( (1._r8 + alpha) * exp(-alpha) - 1._r8 ) / alpha
+            b =  1._r8 - exp(-alpha)
+   
+            if (alpha .gt. 0) then             ! only apply where top level is below 80 km
+               chi_mid = gas_vmr(i,1)          ! molar mixing ratio of O3 at midpoint of top layer
+               chi_0 = chi_mid /  (1._r8 + beta)
+               chi_eff = chi_0 * (a + b)
+               gas_vmr(i,1) = chi_eff
+            end if
+      end do
+   end if
+
+   errmsg = gas_concs%set_vmr(gas_name, gas_vmr)
+   if (len_trim(errmsg) > 0) then
+      call endrun(sub//': ERROR, gas_concs%set_vmr: '//trim(errmsg))
+   end if
+
+   deallocate(gas_vmr)
+   deallocate(mmr)
+
+end subroutine rad_gas_get_vmr
+
+!==================================================================================================
+
+subroutine rrtmgp_set_gases_lw(icall, state, pbuf, nlay, gas_concs)
+
+   ! Set gas vmr for the gases in the radconstants module's gaslist.
+
+   ! The memory management for the gas_concs object is internal.  The arrays passed to it
+   ! are copied to the internally allocated memory.  Each call to the set_vmr method checks
+   ! whether the gas already has memory allocated, and if it does that memory is deallocated
+   ! and new memory is allocated.
+
+   ! arguments
+   integer,                     intent(in)    :: icall      ! index of climate/diagnostic radiation call
+   type(physics_state), target, intent(in)    :: state
+   type(physics_buffer_desc),   pointer       :: pbuf(:)
+   integer,                     intent(in)    :: nlay
+   type(ty_gas_concs),          intent(inout) :: gas_concs
+
+   ! local variables
+   integer :: i, ncol
+   character(len=*), parameter :: sub = 'rrtmgp_set_gases_lw'
+   !--------------------------------------------------------------------------------
+
+   ncol = state%ncol
+   do i = 1, nradgas
+      call rad_gas_get_vmr(icall, gaslist(i), state, pbuf, nlay, ncol, gas_concs)
+   end do
+end subroutine rrtmgp_set_gases_lw
+
+!==================================================================================================
+
+subroutine rrtmgp_set_gases_sw( &
+   icall, state, pbuf, nlay, nday, &
+   idxday, gas_concs)
+
+   ! Return gas_concs with gas volume mixing ratio on DAYLIT columns.
+   ! Set all gases in radconstants gaslist.
+
+   ! arguments
+   integer,                     intent(in)    :: icall      ! index of climate/diagnostic radiation call
+   type(physics_state), target, intent(in)    :: state
+   type(physics_buffer_desc),   pointer       :: pbuf(:)
+   integer,                     intent(in)    :: nlay
+   integer,                     intent(in)    :: nday
+   integer,                     intent(in)    :: idxday(:)
+   type(ty_gas_concs),          intent(inout) :: gas_concs
+
+   ! local variables
+   integer :: i
+   character(len=*), parameter :: sub = 'rrtmgp_set_gases_sw'
+   !----------------------------------------------------------------------------
+
+   ! use the optional argument idxday to specify which columns are sunlit
+    do i = 1,nradgas
+      call rad_gas_get_vmr(icall, gaslist(i), state, pbuf, nlay, nday, gas_concs, idxday=idxday)
+   end do
+
+end subroutine rrtmgp_set_gases_sw
+
+!==================================================================================================
+
+subroutine rrtmgp_set_cloud_lw( &
+   state, pbuf, ncol, nlay, nlaycam, &
+   cld, cldfsnow, cldfgrau, cldfprime, graupel_in_rad, &
+   kdist_lw, cloud_lw, cld_lw_abs_cloudsim, snow_lw_abs_cloudsim, grau_lw_abs_cloudsim)
+
+   ! Compute combined cloud optical properties.
+   ! Create MCICA stochastic arrays for cloud LW optical properties.
+   ! Initialize optical properties object (cloud_lw) and load with MCICA columns.
+
+   ! arguments
+   type(physics_state),         intent(in)  :: state
+   type(physics_buffer_desc),   pointer     :: pbuf(:)
+   integer,  intent(in) :: ncol           ! number of columns in CAM chunk
+   integer,  intent(in) :: nlay           ! number of layers in radiation calculation (may include "extra layer")
+   integer,  intent(in) :: nlaycam        ! number of CAM layers in radiation calculation
+   real(r8), pointer    :: cld(:,:)       ! cloud fraction (liq+ice)
+   real(r8), pointer    :: cldfsnow(:,:)  ! cloud fraction of just "snow clouds"
+   real(r8), pointer    :: cldfgrau(:,:)  ! cloud fraction of just "graupel clouds"
+   real(r8), intent(in) :: cldfprime(pcols,pver) ! combined cloud fraction
+
+   logical,                     intent(in)  :: graupel_in_rad ! use graupel in radiation code
+   class(ty_gas_optics_rrtmgp), intent(in)  :: kdist_lw
+   type(ty_optical_props_1scl), intent(out) :: cloud_lw
+
+   ! Diagnostic outputs
+   real(r8), intent(out) :: cld_lw_abs_cloudsim(pcols,pver) ! in-cloud liq+ice optical depth (for COSP)
+   real(r8), intent(out) :: snow_lw_abs_cloudsim(pcols,pver)! in-cloud snow optical depth (for COSP)
+   real(r8), intent(out) :: grau_lw_abs_cloudsim(pcols,pver)! in-cloud Graupel optical depth (for COSP)
+
+   ! Local variables
+
+   integer :: i, k
+
+   ! cloud radiative parameters are "in cloud" not "in cell"
+   real(r8) :: liq_lw_abs(nlwbands,pcols,pver)   ! liquid absorption optics depth (LW)
+   real(r8) :: ice_lw_abs(nlwbands,pcols,pver)   ! ice absorption optics depth (LW)
+   real(r8) :: cld_lw_abs(nlwbands,pcols,pver)   ! cloud absorption optics depth (LW)
+   real(r8) :: snow_lw_abs(nlwbands,pcols,pver)  ! snow absorption optics depth (LW)
+   real(r8) :: grau_lw_abs(nlwbands,pcols,pver)  ! graupel absorption optics depth (LW)
+   real(r8) :: c_cld_lw_abs(nlwbands,pcols,pver) ! combined cloud absorption optics depth (LW)
+
+   ! Arrays for converting from CAM chunks to RRTMGP inputs.
+   real(r8) :: cldf(ncol,nlaycam)
+   real(r8) :: tauc(nlwbands,ncol,nlaycam)
+   real(r8) :: taucmcl(nlwgpts,ncol,nlaycam)
+
+   character(len=128) :: errmsg
+   character(len=*), parameter :: sub = 'rrtmgp_set_cloud_lw'
+   !--------------------------------------------------------------------------------
+
+   ! Combine the cloud optical properties.  These calculations are done on CAM "chunks".
+
+   ! gammadist liquid optics
+   call liquid_cloud_get_rad_props_lw(state, pbuf, liq_lw_abs)
+   ! Mitchell ice optics
+   call ice_cloud_get_rad_props_lw(state, pbuf, ice_lw_abs)
+
+   cld_lw_abs(:,:ncol,:) = liq_lw_abs(:,:ncol,:) + ice_lw_abs(:,:ncol,:)
+
+   if (associated(cldfsnow)) then
+      ! add in snow
+      call snow_cloud_get_rad_props_lw(state, pbuf, snow_lw_abs)
+      do i = 1, ncol
+         do k = 1, pver
+            if (cldfprime(i,k) > 0._r8) then
+               c_cld_lw_abs(:,i,k) = ( cldfsnow(i,k)*snow_lw_abs(:,i,k) &
+                                            + cld(i,k)*cld_lw_abs(:,i,k) )/cldfprime(i,k)
+            else
+               c_cld_lw_abs(:,i,k) = 0._r8
+            end if
+         end do
+      end do
+   else
+      c_cld_lw_abs(:,:ncol,:) = cld_lw_abs(:,:ncol,:)
+   end if
+
+   ! add in graupel
+   if (associated(cldfgrau) .and. graupel_in_rad) then
+      call grau_cloud_get_rad_props_lw(state, pbuf, grau_lw_abs)
+      do i = 1, ncol
+         do k = 1, pver
+            if (cldfprime(i,k) > 0._r8) then
+               c_cld_lw_abs(:,i,k) = ( cldfgrau(i,k)*grau_lw_abs(:,i,k) &
+                                            + cld(i,k)*c_cld_lw_abs(:,i,k) )/cldfprime(i,k)
+            else
+               c_cld_lw_abs(:,i,k) = 0._r8
+            end if
+         end do
+      end do
+   end if
+
+   ! Cloud optics for COSP
+   cld_lw_abs_cloudsim  = cld_lw_abs(idx_lw_cloudsim,:,:)
+   snow_lw_abs_cloudsim = snow_lw_abs(idx_lw_cloudsim,:,:)
+   grau_lw_abs_cloudsim = grau_lw_abs(idx_lw_cloudsim,:,:)
+   
+   ! Extract just the layers of CAM where RRTMGP does calculations.
+
+   ! Subset "chunk" data so just the number of CAM layers in the
+   ! radiation calculation are used by MCICA to produce subcolumns.
+   cldf = cldfprime(:ncol, ktopcam:)
+   tauc = c_cld_lw_abs(:, :ncol, ktopcam:)
+
+   ! Enforce tauc >= 0.
+   tauc = merge(tauc, 0.0_r8, tauc > 0.0_r8)
+   
+   ! MCICA uses spectral data (on bands) to construct subcolumns (one per g-point)
+   call mcica_subcol_lw( &
+      kdist_lw, nlwbands, nlwgpts, ncol, nlaycam, &
+      nlwgpts, state%pmid, cldf, tauc, taucmcl    )
+
+   errmsg =cloud_lw%alloc_1scl(ncol, nlay, kdist_lw)
+   if (len_trim(errmsg) > 0) then
+      call endrun(sub//': ERROR: cloud_lw%alloc_1scalar: '//trim(errmsg))
+   end if
+
+   ! If there is an extra layer in the radiation then this initialization
+   ! will provide zero optical depths there.
+   cloud_lw%tau = 0.0_r8
+
+   ! Set the properties on g-points.
+   do i = 1, nlwgpts
+      cloud_lw%tau(:,ktoprad:,i) = taucmcl(i,:,:)
+   end do
+
+   ! validate checks that: tau > 0
+   errmsg = cloud_lw%validate()
+   if (len_trim(errmsg) > 0) then
+      call endrun(sub//': ERROR: cloud_lw%validate: '//trim(errmsg))
+   end if
+
+end subroutine rrtmgp_set_cloud_lw
+
+!==================================================================================================
+
+subroutine rrtmgp_set_cloud_sw( &
+   state, pbuf, nlay, nday, idxday, &
+   nnite, idxnite, pmid, cld, cldfsnow, &
+   cldfgrau, cldfprime, graupel_in_rad, kdist_sw, cloud_sw, &
+   tot_cld_vistau, tot_icld_vistau, liq_icld_vistau, ice_icld_vistau, snow_icld_vistau, &
+   grau_icld_vistau, cld_tau_cloudsim, snow_tau_cloudsim, grau_tau_cloudsim)
+
+   ! Compute combined cloud optical properties.
+   ! Create MCICA stochastic arrays for cloud SW optical properties.
+   ! Initialize optical properties object (cloud_sw) and load with MCICA columns.
+
+   ! arguments
+   type(physics_state), target, intent(in) :: state
+   type(physics_buffer_desc), pointer      :: pbuf(:)
+   integer,  intent(in) :: nlay           ! number of layers in radiation calculation (may include "extra layer")
+   integer,  intent(in) :: nday           ! number of daylight columns
+   integer,  intent(in) :: idxday(pcols)  ! indices of daylight columns in the chunk
+   integer,  intent(in) :: nnite          ! number of night columns
+   integer,  intent(in) :: idxnite(pcols) ! indices of night columns in the chunk
+
+   real(r8), intent(in) :: pmid(nday,nlay)! pressure at layer midpoints (Pa) used to seed RNG.
+
+   real(r8), pointer    :: cld(:,:)      ! cloud fraction (liq+ice)
+   real(r8), pointer    :: cldfsnow(:,:) ! cloud fraction of just "snow clouds"
+   real(r8), pointer    :: cldfgrau(:,:) ! cloud fraction of just "graupel clouds"
+   real(r8), intent(in) :: cldfprime(pcols,pver) ! combined cloud fraction
+
+   logical,                     intent(in)  :: graupel_in_rad ! graupel in radiation code
+   class(ty_gas_optics_rrtmgp), intent(in)  :: kdist_sw  ! shortwave gas optics object
+   type(ty_optical_props_2str), intent(out) :: cloud_sw  ! SW cloud optical properties object
+
+   ! Diagnostic outputs
+   real(r8), intent(out) :: tot_cld_vistau(pcols,pver)   ! gbx total cloud optical depth
+   real(r8), intent(out) :: tot_icld_vistau(pcols,pver)  ! in-cld total cloud optical depth
+   real(r8), intent(out) :: liq_icld_vistau(pcols,pver)  ! in-cld liq cloud optical depth
+   real(r8), intent(out) :: ice_icld_vistau(pcols,pver)  ! in-cld ice cloud optical depth
+   real(r8), intent(out) :: snow_icld_vistau(pcols,pver) ! snow in-cloud visible sw optical depth
+   real(r8), intent(out) :: grau_icld_vistau(pcols,pver) ! Graupel in-cloud visible sw optical depth
+   real(r8), intent(out) :: cld_tau_cloudsim(pcols,pver) ! in-cloud liq+ice optical depth (for COSP)
+   real(r8), intent(out) :: snow_tau_cloudsim(pcols,pver)! in-cloud snow optical depth (for COSP)
+   real(r8), intent(out) :: grau_tau_cloudsim(pcols,pver)! in-cloud Graupel optical depth (for COSP)
+
+   ! Local variables
+
+   integer :: i, k, ncol
+   integer :: igpt, nver
+   integer :: istat
+   integer, parameter :: changeseed = 1
+
+   ! cloud radiative parameters are "in cloud" not "in cell"
+   real(r8) :: ice_tau    (nswbands,pcols,pver) ! ice extinction optical depth
+   real(r8) :: ice_tau_w  (nswbands,pcols,pver) ! ice single scattering albedo * tau
+   real(r8) :: ice_tau_w_g(nswbands,pcols,pver) ! ice asymmetry parameter * tau * w
+   real(r8) :: liq_tau    (nswbands,pcols,pver) ! liquid extinction optical depth
+   real(r8) :: liq_tau_w  (nswbands,pcols,pver) ! liquid single scattering albedo * tau
+   real(r8) :: liq_tau_w_g(nswbands,pcols,pver) ! liquid asymmetry parameter * tau * w
+   real(r8) :: cld_tau    (nswbands,pcols,pver) ! cloud extinction optical depth
+   real(r8) :: cld_tau_w  (nswbands,pcols,pver) ! cloud single scattering albedo * tau
+   real(r8) :: cld_tau_w_g(nswbands,pcols,pver) ! cloud asymmetry parameter * w * tau
+   real(r8) :: snow_tau    (nswbands,pcols,pver) ! snow extinction optical depth
+   real(r8) :: snow_tau_w  (nswbands,pcols,pver) ! snow single scattering albedo * tau
+   real(r8) :: snow_tau_w_g(nswbands,pcols,pver) ! snow asymmetry parameter * tau * w
+   real(r8) :: grau_tau    (nswbands,pcols,pver) ! graupel extinction optical depth
+   real(r8) :: grau_tau_w  (nswbands,pcols,pver) ! graupel single scattering albedo * tau
+   real(r8) :: grau_tau_w_g(nswbands,pcols,pver) ! graupel asymmetry parameter * tau * w
+   real(r8) :: c_cld_tau    (nswbands,pcols,pver) ! combined cloud extinction optical depth
+   real(r8) :: c_cld_tau_w  (nswbands,pcols,pver) ! combined cloud single scattering albedo * tau
+   real(r8) :: c_cld_tau_w_g(nswbands,pcols,pver) ! combined cloud asymmetry parameter * w * tau
+
+   ! RRTMGP does not use this property in its 2-stream calculations.
+   real(r8) :: sw_tau_w_f(nswbands,pcols,pver) ! Forward scattered fraction * tau * w.
+
+   ! Arrays for converting from CAM chunks to RRTMGP inputs.
+   real(r8), allocatable :: cldf(:,:)
+   real(r8), allocatable :: tauc(:,:,:)
+   real(r8), allocatable :: ssac(:,:,:)
+   real(r8), allocatable :: asmc(:,:,:)
+   real(r8), allocatable :: taucmcl(:,:,:)
+   real(r8), allocatable :: ssacmcl(:,:,:)
+   real(r8), allocatable :: asmcmcl(:,:,:)
+   real(r8), allocatable :: day_cld_tau(:,:,:)
+   real(r8), allocatable :: day_cld_tau_w(:,:,:)
+   real(r8), allocatable :: day_cld_tau_w_g(:,:,:)
+
+   character(len=128) :: errmsg
+   character(len=*), parameter :: sub = 'rrtmgp_set_cloud_sw'
+   !--------------------------------------------------------------------------------
+
+   ncol = state%ncol
+
+   ! Combine the cloud optical properties.  These calculations are done on CAM "chunks".
+
+   ! gammadist liquid optics
+   call get_liquid_optics_sw(state, pbuf, liq_tau, liq_tau_w, liq_tau_w_g, sw_tau_w_f)
+   ! Mitchell ice optics
+   call get_ice_optics_sw(state, pbuf, ice_tau, ice_tau_w, ice_tau_w_g, sw_tau_w_f)
+
+   cld_tau(:,:ncol,:)     =  liq_tau(:,:ncol,:)     + ice_tau(:,:ncol,:)
+   cld_tau_w(:,:ncol,:)   =  liq_tau_w(:,:ncol,:)   + ice_tau_w(:,:ncol,:)
+   cld_tau_w_g(:,:ncol,:) =  liq_tau_w_g(:,:ncol,:) + ice_tau_w_g(:,:ncol,:)
+
+   ! add in snow
+   if (associated(cldfsnow)) then
+      call get_snow_optics_sw(state, pbuf, snow_tau, snow_tau_w, snow_tau_w_g, sw_tau_w_f)
+      do i = 1, ncol
+         do k = 1, pver
+            if (cldfprime(i,k) > 0._r8) then
+               c_cld_tau(:,i,k)     = ( cldfsnow(i,k)*snow_tau(:,i,k) &
+                                      + cld(i,k)*cld_tau(:,i,k) )/cldfprime(i,k)
+               c_cld_tau_w(:,i,k)   = ( cldfsnow(i,k)*snow_tau_w(:,i,k)  &
+                                      + cld(i,k)*cld_tau_w(:,i,k) )/cldfprime(i,k)
+               c_cld_tau_w_g(:,i,k) = ( cldfsnow(i,k)*snow_tau_w_g(:,i,k) &
+                                      + cld(i,k)*cld_tau_w_g(:,i,k) )/cldfprime(i,k)
+            else
+               c_cld_tau(:,i,k)     = 0._r8
+               c_cld_tau_w(:,i,k)   = 0._r8
+               c_cld_tau_w_g(:,i,k) = 0._r8
+            end if
+         end do
+      end do
+   else
+      c_cld_tau(:,:ncol,:)     = cld_tau(:,:ncol,:)
+      c_cld_tau_w(:,:ncol,:)   = cld_tau_w(:,:ncol,:)
+      c_cld_tau_w_g(:,:ncol,:) = cld_tau_w_g(:,:ncol,:)
+   end if
+
+   ! add in graupel
+   if (associated(cldfgrau) .and. graupel_in_rad) then
+      call get_grau_optics_sw(state, pbuf, grau_tau, grau_tau_w, grau_tau_w_g, sw_tau_w_f)
+      do i = 1, ncol
+         do k = 1, pver
+            if (cldfprime(i,k) > 0._r8) then
+               c_cld_tau(:,i,k)     = ( cldfgrau(i,k)*grau_tau(:,i,k) &
+                                      + cld(i,k)*c_cld_tau(:,i,k) )/cldfprime(i,k)
+               c_cld_tau_w(:,i,k)   = ( cldfgrau(i,k)*grau_tau_w(:,i,k)  &
+                                      + cld(i,k)*c_cld_tau_w(:,i,k) )/cldfprime(i,k)
+               c_cld_tau_w_g(:,i,k) = ( cldfgrau(i,k)*grau_tau_w_g(:,i,k) &
+                                      + cld(i,k)*c_cld_tau_w_g(:,i,k) )/cldfprime(i,k)
+            else
+               c_cld_tau(:,i,k)     = 0._r8
+               c_cld_tau_w(:,i,k)   = 0._r8
+               c_cld_tau_w_g(:,i,k) = 0._r8
+            end if
+         end do
+      end do
+   end if
+
+   ! cloud optical properties need to be re-ordered from the RRTMG spectral bands
+   ! (assumed in the optics datasets) to RRTMGP's
+   ice_tau(:,:ncol,:)       = ice_tau(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   liq_tau(:,:ncol,:)       = liq_tau(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   c_cld_tau(:,:ncol,:)     = c_cld_tau(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   c_cld_tau_w(:,:ncol,:)   = c_cld_tau_w(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   c_cld_tau_w_g(:,:ncol,:) = c_cld_tau_w_g(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   if (associated(cldfsnow)) then
+      snow_tau(:,:ncol,:)   = snow_tau(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   end if
+   if (associated(cldfgrau) .and. graupel_in_rad) then
+      grau_tau(:,:ncol,:)   = grau_tau(rrtmg_to_rrtmgp_swbands,:ncol,:)
+   end if
+
+   ! Set arrays for diagnostic output.
+   ! cloud optical depth fields for the visible band
+   tot_icld_vistau(:ncol,:) = c_cld_tau(idx_sw_diag,:ncol,:)
+   liq_icld_vistau(:ncol,:) = liq_tau(idx_sw_diag,:ncol,:)
+   ice_icld_vistau(:ncol,:) = ice_tau(idx_sw_diag,:ncol,:)
+   if (associated(cldfsnow)) then
+      snow_icld_vistau(:ncol,:) = snow_tau(idx_sw_diag,:ncol,:)
+   endif
+   if (associated(cldfgrau) .and. graupel_in_rad) then
+      grau_icld_vistau(:ncol,:) = grau_tau(idx_sw_diag,:ncol,:)
+   endif
+
+   ! multiply by total cloud fraction to get gridbox value
+   tot_cld_vistau(:ncol,:) = c_cld_tau(idx_sw_diag,:ncol,:)*cldfprime(:ncol,:)
+
+   ! overwrite night columns with fillvalue
+   do i = 1, Nnite
+      tot_cld_vistau(IdxNite(i),:)   = fillvalue
+      tot_icld_vistau(IdxNite(i),:)  = fillvalue
+      liq_icld_vistau(IdxNite(i),:)  = fillvalue
+      ice_icld_vistau(IdxNite(i),:)  = fillvalue
+      if (associated(cldfsnow)) then
+         snow_icld_vistau(IdxNite(i),:) = fillvalue
+      end if
+      if (associated(cldfgrau) .and. graupel_in_rad) then
+         grau_icld_vistau(IdxNite(i),:) = fillvalue
+      end if
+   end do
+
+   ! Cloud optics for COSP
+   cld_tau_cloudsim = cld_tau(idx_sw_cloudsim,:,:)
+   snow_tau_cloudsim = snow_tau(idx_sw_cloudsim,:,:)
+   grau_tau_cloudsim = grau_tau(idx_sw_cloudsim,:,:)
+
+   ! if no daylight columns the cloud_sw object isn't initialized
+   if (nday > 0) then
+
+      ! number of CAM's layers in radiation calculation.  Does not include the "extra layer".
+      nver = pver - ktopcam + 1
+
+      allocate( &
+         cldf(nday,nver),                      &
+         day_cld_tau(nswbands,nday,nver),      &
+         day_cld_tau_w(nswbands,nday,nver),    &
+         day_cld_tau_w_g(nswbands,nday,nver),  &
+         tauc(nswbands,nday,nver), taucmcl(nswgpts,nday,nver), &
+         ssac(nswbands,nday,nver), ssacmcl(nswgpts,nday,nver), &
+         asmc(nswbands,nday,nver), asmcmcl(nswgpts,nday,nver), stat=istat)
+      call alloc_err(istat, sub, 'cldf,..,asmcmcl', 9*nswgpts*nday*nver)
+
+      ! Subset "chunk" data so just the daylight columns, and the number of CAM layers in the
+      ! radiation calculation are used by MCICA to produce subcolumns.
+      cldf            = cldfprime(       idxday(1:nday), ktopcam:)
+      day_cld_tau     = c_cld_tau(    :, idxday(1:nday), ktopcam:)
+      day_cld_tau_w   = c_cld_tau_w(  :, idxday(1:nday), ktopcam:)
+      day_cld_tau_w_g = c_cld_tau_w_g(:, idxday(1:nday), ktopcam:)
+
+      ! Compute the optical properties needed for the 2-stream calculations.  These calculations
+      ! are the same as the RRTMG version.
+
+      ! set cloud optical depth, clip @ zero
+      tauc = merge(day_cld_tau, 0.0_r8, day_cld_tau > 0.0_r8)
+      ! set value of asymmetry
+      asmc = merge(day_cld_tau_w_g / max(day_cld_tau_w, tiny), 0.0_r8, day_cld_tau_w > 0.0_r8)
+      ! set value of single scattering albedo
+      ssac = merge(max(day_cld_tau_w, tiny) / max(tauc, tiny), 1.0_r8 , tauc > 0.0_r8)
+      ! set asymmetry to zero when tauc = 0
+      asmc = merge(asmc, 0.0_r8, tauc > 0.0_r8)
+
+      ! MCICA uses spectral data (on bands) to construct subcolumns (one per g-point)
+      call mcica_subcol_sw( &
+         kdist_sw, nswbands, nswgpts, nday, nlay, &
+         nver, changeseed, pmid, cldf, tauc,     &
+         ssac, asmc, taucmcl, ssacmcl, asmcmcl)
+   
+      ! Initialize object for SW cloud optical properties.
+      errmsg = cloud_sw%alloc_2str(nday, nlay, kdist_sw)
+      if (len_trim(errmsg) > 0) then
+         call endrun(trim(sub)//': ERROR: cloud_sw%alloc_2str: '//trim(errmsg))
+      end if
+
+      ! If there is an extra layer in the radiation then this initialization
+      ! will provide the optical properties there.
+      cloud_sw%tau = 0.0_r8
+      cloud_sw%ssa = 1.0_r8
+      cloud_sw%g   = 0.0_r8
+
+      ! Set the properties on g-points.
+      do igpt = 1,nswgpts
+         cloud_sw%g  (:,ktoprad:,igpt) = asmcmcl(igpt,:,:)
+         cloud_sw%ssa(:,ktoprad:,igpt) = ssacmcl(igpt,:,:)
+         cloud_sw%tau(:,ktoprad:,igpt) = taucmcl(igpt,:,:)
+      end do
+
+      ! validate checks that: tau > 0, ssa is in range [0,1], and g is in range [-1,1].
+      errmsg = cloud_sw%validate()
+      if (len_trim(errmsg) > 0) then
+         call endrun(sub//': ERROR: cloud_sw%validate: '//trim(errmsg))
+      end if
+
+      ! delta scaling adjusts for forward scattering
+      errmsg = cloud_sw%delta_scale()
+      if (len_trim(errmsg) > 0) then
+         call endrun(sub//': ERROR: cloud_sw%delta_scale: '//trim(errmsg))
+      end if
+
+      ! All information is in cloud_sw, now deallocate local vars.
+      deallocate( &
+         cldf, tauc, ssac, asmc, &
+         taucmcl, ssacmcl, asmcmcl,&
+         day_cld_tau, day_cld_tau_w, day_cld_tau_w_g )
+
+   end if
+
+end subroutine rrtmgp_set_cloud_sw
+
+!==================================================================================================
+
+subroutine rrtmgp_set_aer_lw(icall, state, pbuf, aer_lw)
+
+   ! Load LW aerosol optical properties into the RRTMGP object.
+
+   ! Arguments
+   integer,                     intent(in) :: icall
+   type(physics_state), target, intent(in) :: state
+   type(physics_buffer_desc),   pointer    :: pbuf(:)
+
+   type(ty_optical_props_1scl), intent(inout) :: aer_lw
+
+   ! Local variables
+   integer :: ncol
+
+   ! Aerosol LW absorption optical depth
+   real(r8) :: aer_lw_abs (pcols,pver,nlwbands)
+
+   character(len=*), parameter :: sub = 'rrtmgp_set_aer_lw'
+   character(len=128) :: errmsg
+   !--------------------------------------------------------------------------------
+
+   ncol = state%ncol
+
+   ! Get aerosol longwave optical properties.
+   call aer_rad_props_lw(icall, state, pbuf, aer_lw_abs)
+
+   ! If there is an extra layer in the radiation then this initialization
+   ! will provide zero optical depths there.
+   aer_lw%tau = 0.0_r8
+
+   aer_lw%tau(:ncol, ktoprad:, :) = aer_lw_abs(:ncol, ktopcam:, :)
+
+   errmsg = aer_lw%validate()
+   if (len_trim(errmsg) > 0) then
+      call endrun(sub//': ERROR: aer_lw%validate: '//trim(errmsg))
+   end if
+end subroutine rrtmgp_set_aer_lw
+
+!==================================================================================================
+
+subroutine rrtmgp_set_aer_sw( &
+   icall, state, pbuf, nday, idxday, nnite, idxnite, aer_sw)
+
+   ! Load SW aerosol optical properties into the RRTMGP object.
+
+   ! Arguments
+   integer,                     intent(in) :: icall
+   type(physics_state), target, intent(in) :: state
+   type(physics_buffer_desc), pointer      :: pbuf(:)
+   integer,  intent(in) :: nday
+   integer,  intent(in) :: idxday(:)
+   integer,  intent(in) :: nnite          ! number of night columns
+   integer,  intent(in) :: idxnite(pcols) ! indices of night columns in the chunk
+
+   type(ty_optical_props_2str), intent(inout) :: aer_sw
+
+   ! local variables
+   integer  :: i
+
+   ! The optical arrays dimensioned in the vertical as 0:pver.
+   ! The index 0 is for the extra layer used in the radiation
+   ! calculation.  The index ktopcam assumes the CAM vertical indices are
+   ! in the range 1:pver, so using this index correctly ignores vertical
+   ! index 0.  If an "extra" layer is used in the calculations, it is
+   ! provided and set in the RRTMGP aerosol object aer_sw.
+   real(r8) :: aer_tau    (pcols,0:pver,nswbands) ! extinction optical depth
+   real(r8) :: aer_tau_w  (pcols,0:pver,nswbands) ! single scattering albedo * tau
+   real(r8) :: aer_tau_w_g(pcols,0:pver,nswbands) ! asymmetry parameter * w * tau
+   real(r8) :: aer_tau_w_f(pcols,0:pver,nswbands) ! forward scattered fraction * w * tau
+                                                  ! aer_tau_w_f is not used by RRTMGP.
+   character(len=*), parameter :: sub = 'rrtmgp_set_aer_sw'
+   !--------------------------------------------------------------------------------
+
+   ! Get aerosol shortwave optical properties.
+   ! Make outfld calls for aerosol optical property diagnostics.
+   call aer_rad_props_sw( &
+      icall, state, pbuf, nnite, idxnite, &
+      aer_tau, aer_tau_w, aer_tau_w_g, aer_tau_w_f)
+
+   ! The aer_sw object is only initialized if nday > 0.
+   if (nday > 0) then
+
+      ! aerosol optical properties need to be re-ordered from the RRTMG spectral bands
+      ! (as assumed in the optics datasets) to the RRTMGP band order.
+      aer_tau(:,:,:)     = aer_tau(    :,:,rrtmg_to_rrtmgp_swbands)
+      aer_tau_w(:,:,:)   = aer_tau_w(  :,:,rrtmg_to_rrtmgp_swbands)
+      aer_tau_w_g(:,:,:) = aer_tau_w_g(:,:,rrtmg_to_rrtmgp_swbands)
+                  
+      ! If there is an extra layer in the radiation then this initialization
+      ! will provide default values.
+      aer_sw%tau = 0.0_r8
+      aer_sw%ssa = 1.0_r8
+      aer_sw%g   = 0.0_r8
+
+      ! CAM fields are products tau, tau*ssa, tau*ssa*asy
+      ! Fields expected by RRTMGP are computed by
+      ! aer_sw%tau = aer_tau
+      ! aer_sw%ssa = aer_tau_w / aer_tau
+      ! aer_sw%g   = aer_tau_w_g / aer_taw_w
+      ! aer_sw arrays have dimensions of (nday,nlay,nswbands)
+
+      do i = 1, nday
+         ! set aerosol optical depth, clip to zero
+         aer_sw%tau(i,ktoprad:,:) = max(aer_tau(idxday(i),ktopcam:,:), 0._r8)
+         ! set value of single scattering albedo
+         aer_sw%ssa(i,ktoprad:,:) = merge(aer_tau_w(idxday(i),ktopcam:,:)/aer_tau(idxday(i),ktopcam:,:), &
+                                          1._r8, aer_tau(idxday(i),ktopcam:,:) > 0._r8)
+         ! set value of asymmetry
+         aer_sw%g(i,ktoprad:,:) = merge(aer_tau_w_g(idxday(i),ktopcam:,:)/aer_tau_w(idxday(i),ktopcam:,:), &
+                                        0._r8, aer_tau_w(idxday(i),ktopcam:,:) > tiny)
+      end do
+
+      ! impose limits on the components
+      aer_sw%ssa = min(max(aer_sw%ssa, 0._r8), 1._r8)
+      aer_sw%g   = min(max(aer_sw%g, -1._r8), 1._r8)
+
+   end if
+
+end subroutine rrtmgp_set_aer_sw
+
+!==================================================================================================
+
+end module rrtmgp_inputs
diff --git a/src/physics/simple/radconstants.F90 b/src/physics/simple/radconstants.F90
index b69fac1552..4476dc6669 100644
--- a/src/physics/simple/radconstants.F90
+++ b/src/physics/simple/radconstants.F90
@@ -15,11 +15,9 @@ module radconstants
 integer, parameter, public :: idx_lw_diag = 1
 integer, parameter, public :: idx_nir_diag = 1
 integer, parameter, public :: idx_uv_diag = 1
-integer, parameter, public :: nrh = 1
-integer, parameter, public :: ot_length = 32
 
 public :: rad_gas_index
-public :: get_lw_spectral_boundaries
+public :: get_lw_spectral_boundaries, get_sw_spectral_boundaries
 
 integer, public, parameter :: gasnamelength = 1
 integer, public, parameter :: nradgas = 1
@@ -39,6 +37,7 @@ integer function rad_gas_index(gasname)
 end function rad_gas_index
 
 !------------------------------------------------------------------------------
+
 subroutine get_lw_spectral_boundaries(low_boundaries, high_boundaries, units)
    ! stub should not be called
 
@@ -49,4 +48,18 @@ subroutine get_lw_spectral_boundaries(low_boundaries, high_boundaries, units)
 
 end subroutine get_lw_spectral_boundaries
 
+!------------------------------------------------------------------------------
+
+subroutine get_sw_spectral_boundaries(low_boundaries, high_boundaries, units)
+   ! stub should not be called
+
+   real(r8), intent(out) :: low_boundaries(nswbands), high_boundaries(nswbands)
+   character(*), intent(in) :: units ! requested units
+
+   call endrun('get_sw_spectral_boundaries: ERROR: this is a stub')
+
+end subroutine get_sw_spectral_boundaries
+
+!------------------------------------------------------------------------------
+
 end module radconstants
diff --git a/src/physics/spcam/crm/CLUBB/crmx_mt95.f90 b/src/physics/spcam/crm/CLUBB/crmx_mt95.f90
index 14d75bc733..7c2ff7d9db 100644
--- a/src/physics/spcam/crm/CLUBB/crmx_mt95.f90
+++ b/src/physics/spcam/crm/CLUBB/crmx_mt95.f90
@@ -1,10 +1,10 @@
 ! A C-program for MT19937, with initialization improved 2002/1/26.
 ! Coded by Takuji Nishimura and Makoto Matsumoto.                 
 
-! Code converted to Fortran 95 by José Rui Faustino de Sousa
+! Code converted to Fortran 95 by Jose Rui Faustino de Sousa
 ! Date: 2002-02-01
 
-! Enhanced version by José Rui Faustino de Sousa
+! Enhanced version by Jose Rui Faustino de Sousa
 ! Date: 2003-04-30
 
 ! Interface:
@@ -1310,7 +1310,7 @@ subroutine genrand_res53_7d( r )
 
   end subroutine genrand_res53_7d
   ! These real versions are due to Isaku Wada, 2002/01/09 added 
-  ! Altered by José Sousa genrand_real[1-3] will not return exactely
+  ! Altered by Jose Sousa genrand_real[1-3] will not return exactely
   ! the same values but should have the same properties and are faster
 
 end module crmx_mt95
diff --git a/test/system/TR8.sh b/test/system/TR8.sh
index f56c9bc636..4366d63c84 100755
--- a/test/system/TR8.sh
+++ b/test/system/TR8.sh
@@ -12,6 +12,8 @@ ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/components/cam/src/physics/camrt
 rc=`expr $? + $rc`
 ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/components/cam/src/physics/rrtmg -s aer_src
 rc=`expr $? + $rc`
+ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/components/cam/src/physics/rrtmgp -s data,ext
+rc=`expr $? + $rc`
 ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/components/cam/src/physics/simple
 rc=`expr $? + $rc`
 ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/components/cam/src/physics/waccm
@@ -27,6 +29,8 @@ ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/src/physics/camrt
 rc=`expr $? + $rc`
 ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/src/physics/rrtmg -s aer_src
 rc=`expr $? + $rc`
+ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/src/physics/rrtmgp -s data,ext
+rc=`expr $? + $rc`
 ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/src/physics/simple
 rc=`expr $? + $rc`
 ruby $ADDREALKIND_EXE -r r8 -l 1 -d $CAM_ROOT/src/physics/waccm