diff --git a/cicecore/cicedyn/dynamics/ice_dyn_shared.F90 b/cicecore/cicedyn/dynamics/ice_dyn_shared.F90
index 5e2757b93..a12e6fddd 100644
--- a/cicecore/cicedyn/dynamics/ice_dyn_shared.F90
+++ b/cicecore/cicedyn/dynamics/ice_dyn_shared.F90
@@ -181,7 +181,7 @@ subroutine alloc_dyn_shared
          iceTmask  (nx_block,ny_block,max_blocks), & ! T mask for dynamics
          iceUmask  (nx_block,ny_block,max_blocks), & ! U mask for dynamics
          fcor_blk  (nx_block,ny_block,max_blocks), & ! Coriolis
-         DminTarea (nx_block,ny_block,max_blocks), & ! 
+         DminTarea (nx_block,ny_block,max_blocks), & !
          stat=ierr)
       if (ierr/=0) call abort_ice(subname//': Out of memory')
 
@@ -240,7 +240,7 @@ subroutine init_dyn_shared (dt)
 
       call set_evp_parameters (dt)
       ! allocate dyn shared (init_uvel,init_vvel)
-      call alloc_dyn_shared     
+      call alloc_dyn_shared
       ! Set halo_dynbundle, this is empirical at this point, could become namelist
       halo_dynbundle = .true.
       nprocs = get_num_procs()
diff --git a/cicecore/cicedyn/dynamics/ice_dyn_vp.F90 b/cicecore/cicedyn/dynamics/ice_dyn_vp.F90
index 5a01f4308..3915004b4 100644
--- a/cicecore/cicedyn/dynamics/ice_dyn_vp.F90
+++ b/cicecore/cicedyn/dynamics/ice_dyn_vp.F90
@@ -88,7 +88,7 @@ module ice_dyn_vp
          reltol_andacc      ! relative tolerance for Anderson acceleration
 
       character (len=char_len), public :: &
-         precond        , & ! preconditioner for fgmres: 'ident' (identity), 'diag' (diagonal), 
+         precond        , & ! preconditioner for fgmres: 'ident' (identity), 'diag' (diagonal),
                             ! 'pgmres' (Jacobi-preconditioned GMRES)
          algo_nonlin    , & ! nonlinear algorithm: 'picard' (Picard iteration), 'anderson' (Anderson acceleration)
          ortho_type         ! type of orthogonalization for FGMRES ('cgs' or 'mgs')
@@ -3344,7 +3344,7 @@ subroutine pgmres (zetax2   , etax2   , &
 
             ! Update workspace with boundary values
             ! NOTE: skipped for efficiency since this is just a preconditioner
-            ! unless bfbflag is active            
+            ! unless bfbflag is active
             if (bfbflag /= 'off') then
                call stack_fields(workspace_x, workspace_y, fld2)
                call ice_timer_start(timer_bound)
@@ -3565,7 +3565,7 @@ subroutine precondition(zetax2      , etax2, &
 
       type (ice_halo), intent(in) :: &
          halo_info_mask !  ghost cell update info for masked halo
-         
+
       real (kind=dbl_kind), dimension (nx_block,ny_block,max_blocks), intent(in) :: &
          vx       , & ! input vector (x components)
          vy           ! input vector (y components)
diff --git a/cicecore/cicedyn/general/ice_forcing.F90 b/cicecore/cicedyn/general/ice_forcing.F90
index 3a2d83530..541efb282 100755
--- a/cicecore/cicedyn/general/ice_forcing.F90
+++ b/cicecore/cicedyn/general/ice_forcing.F90
@@ -118,7 +118,7 @@ module ice_forcing
 
       real (kind=dbl_kind), dimension(:,:,:,:,:), allocatable :: &
           wave_spectrum_data ! field values at 2 temporal data points
- 
+
       character(char_len), public :: &
          atm_data_format, & ! 'bin'=binary or 'nc'=netcdf
          ocn_data_format, & ! 'bin'=binary or 'nc'=netcdf
@@ -5650,7 +5650,7 @@ subroutine get_wave_spec
                   file=__FILE__, line=__LINE__)
             else
 #ifdef USE_NETCDF
-               call wave_spec_data 
+               call wave_spec_data
 #else
                write (nu_diag,*) "wave spectrum file not available, requires cpp USE_NETCDF"
                write (nu_diag,*) "wave spectrum file not available, using default profile"
@@ -5682,7 +5682,7 @@ subroutine wave_spec_data
       use ice_grid, only: hm, tlon, tlat, tmask, umask
       use ice_calendar, only: days_per_year, use_leap_years
 
-      integer (kind=int_kind) :: & 
+      integer (kind=int_kind) :: &
           ncid        , & ! netcdf file id
           i, j, freq  , &
           ixm,ixx,ixp , & ! record numbers for neighboring months
@@ -5710,7 +5710,7 @@ subroutine wave_spec_data
          wave_spectrum_profile  ! wave spectrum
 
       character(len=64) :: fieldname !netcdf field name
-      character(char_len_long) :: spec_file 
+      character(char_len_long) :: spec_file
       character(char_len) :: wave_spec_type
       logical (kind=log_kind) :: wave_spec
       character(len=*), parameter :: subname = '(wave_spec_data)'
@@ -5736,7 +5736,7 @@ subroutine wave_spec_data
       yr = fyear  ! current year
     !-------------------------------------------------------------------
     ! 6-hourly data
-    ! 
+    !
     ! Assume that the 6-hourly value is located at the end of the
     !  6-hour period.  This is the convention for NCEP reanalysis data.
     !  E.g. record 1 gives conditions at 6 am GMT on 1 January.
@@ -5787,7 +5787,7 @@ subroutine wave_spec_data
               field_type=field_type_scalar)
          call ice_close_nc(ncid)
 
-     
+
       ! Interpolate
       call interpolate_wavespec_data (wave_spectrum_data, wave_spectrum)
 
diff --git a/cicecore/cicedyn/general/ice_init.F90 b/cicecore/cicedyn/general/ice_init.F90
index 2bebd32f6..03ebc0174 100644
--- a/cicecore/cicedyn/general/ice_init.F90
+++ b/cicecore/cicedyn/general/ice_init.F90
@@ -1543,7 +1543,7 @@ subroutine input_data
                write(nu_diag,*) subname//' WARNING: tr_fsd=T but wave_spec=F - not recommended'
             endif
       end if
- 
+
       ! compute grid locations for thermo, u and v fields
 
       grid_ice_thrm = 'T'
diff --git a/cicecore/cicedyn/infrastructure/ice_grid.F90 b/cicecore/cicedyn/infrastructure/ice_grid.F90
index d193eca02..d6c612f00 100644
--- a/cicecore/cicedyn/infrastructure/ice_grid.F90
+++ b/cicecore/cicedyn/infrastructure/ice_grid.F90
@@ -1396,15 +1396,15 @@ subroutine rectgrid
          ! original rectgrid defines latlon first
          call rectgrid_scale_dxdy
       else
-         ! rectgrid no grid spacing. 
+         ! rectgrid no grid spacing.
          ! original method with addition to use namelist lat/lon reference
-         
+
          if (my_task == master_task) then
             work_g1 = c0
             length = dxrect*cm_to_m/radius*rad_to_deg
-            
+
             work_g1(1,:) = lonrefrect ! reference lon from namelist
-            
+
             do j = 1, ny_global
             do i = 2, nx_global
                work_g1(i,j) = work_g1(i-1,j) + length   ! ULON
@@ -1416,13 +1416,13 @@ subroutine rectgrid
                              field_loc_NEcorner, field_type_scalar)
          call ice_HaloExtrapolate(ULON, distrb_info, &
                                   ew_boundary_type, ns_boundary_type)
-         
+
          if (my_task == master_task) then
             work_g1 = c0
             length = dyrect*cm_to_m/radius*rad_to_deg
-            
+
             work_g1(:,1) = latrefrect ! reference latitude from namelist
-            
+
             do i = 1, nx_global
             do j = 2, ny_global
                work_g1(i,j) = work_g1(i,j-1) + length   ! ULAT
@@ -1535,32 +1535,32 @@ subroutine rectgrid
       end subroutine rectgrid
 
 !=======================================================================
-      
+
       subroutine rectgrid_scale_dxdy
-        
+
         ! generate a variable spaced rectangluar grid.
         ! extend spacing from center of grid outward.
         use ice_constants, only: c0, c1, c2, radius, cm_to_m, &
              field_loc_center, field_loc_NEcorner, field_type_scalar
-        
+
         integer (kind=int_kind) :: &
              i, j, iblk, &
              imid, jmid, &
              center1, center2 ! array centers for expanding dx, dy
-      
+
         real (kind=dbl_kind) :: &
              length,  &
              rad_to_deg
 
         real (kind=dbl_kind), dimension(:,:), allocatable :: &
              work_g1
-        
+
         character(len=*), parameter :: subname = '(rectgrid_scale_dxdy)'
-        
+
         call icepack_query_parameters(rad_to_deg_out=rad_to_deg)
 
         allocate(work_g1(nx_global,ny_global))
-        
+
         ! determine dx spacing
         ! strategy: initialize with dxrect.
         ! if want to scale the grid, work from center outwards,
@@ -1568,51 +1568,51 @@ subroutine rectgrid_scale_dxdy
         ! this assumes dx varies in x direction only.
         ! (i.e, dx is the same across same y location)
         if (my_task == master_task) then
-           
+
            ! initialize with initial dxrect
            work_g1(:,:) = dxrect
-           
+
            ! check if nx is even or odd
            ! if even, middle 2 columns are center
            ! of odd,  middle 1 column is center
            if (mod(nx_global,2) == 0) then ! nx_global is even
-              
+
               ! with even number of x locatons,
               ! the center two y columns are center
               center1 = nx_global/2  ! integer math
               center2 = center1 + 1  ! integer math
-              
+
            else ! nx_global = odd
               ! only one center index. set center2=center1
               center1 = ceiling(real(nx_global/2),int_kind)
               center2 = center1
            endif
-           
+
            ! note loop over only half the x grid points (center1)-1
            ! working from the center outward.
            do j = 1, ny_global
            do i = 1, center1-1
               ! work from center1 to left
               work_g1(center1-i,j) = dxscale*work_g1(center1-i+1,j)
-              
+
               ! work from center2 to right
               work_g1(center2+i,j) = dxscale*work_g1(center2+i-1,j)
            enddo ! i
            enddo ! j
-           
+
         endif       ! my_task == master_task
-        
-        
+
+
         ! note work_g1 is converted to meters in primary_grid_lengths_HTN
         call primary_grid_lengths_HTN(work_g1)  ! dxU, dxT, dxN, dxE
-        
+
         ! make ULON array
         if (my_task == master_task) then
-           
+
            ! make first column reference lon in radians.
            ! the remaining work_g1 is still dx in meters
            work_g1(1,:) = lonrefrect/rad_to_deg ! radians
-           
+
            ! loop over remaining points and add spacing to successive
            ! x locations
            do j = 1, ny_global
@@ -1626,7 +1626,7 @@ subroutine rectgrid_scale_dxdy
                             field_loc_NEcorner, field_type_scalar)
         call ice_HaloExtrapolate(ULON, distrb_info, &
                                  ew_boundary_type, ns_boundary_type)
-        
+
         ! determine dy spacing
         ! strategy: initialize with dyrect.
         ! if want to scale the grid, work from center outwards,
@@ -1634,7 +1634,7 @@ subroutine rectgrid_scale_dxdy
         ! this assumes dy varies in y direction only.
         ! (i.e, dy is the same across same x location)
         if (my_task == master_task) then
-           
+
            ! initialize with initial dxrect
            work_g1(:,:) = dyrect
 
@@ -1642,25 +1642,25 @@ subroutine rectgrid_scale_dxdy
            ! if even, middle 2 rows are center
            ! of odd,  middle 1 row is center
            if (mod(ny_global,2) == 0) then ! ny_global is even
-              
+
               ! with even number of x locatons,
               ! the center two y columns are center
               center1 = ny_global/2  ! integer math
               center2 = center1 + 1  ! integer math
-              
+
            else ! ny_global = odd
               ! only one center index. set center2=center1
               center1 = ceiling(real(ny_global/2),int_kind)
               center2 = center1
            endif
-           
+
            ! note loop over only half the y grid points (center1)-1
            ! working from the center outward.
            do i = 1, nx_global
            do j = 1, center1-1
               ! work from center1 to bottom
               work_g1(i,center1-j) = dyscale*work_g1(i,center1-j+1)
-              
+
               ! work from center2 to top
               work_g1(i,center2+j) = dyscale*work_g1(i,center2+j-1)
            enddo ! i
@@ -1668,15 +1668,15 @@ subroutine rectgrid_scale_dxdy
         endif    ! mytask == master_task
         ! note work_g1 is converted to meters primary_grid_lengths_HTE
         call primary_grid_lengths_HTE(work_g1)  ! dyU, dyT, dyN, dyE
-        
+
         ! make ULAT array
         if (my_task == master_task) then
-           
+
            ! make first row reference lat in radians.
            ! the remaining work_g1 is still dy in meters
            work_g1(:,1) = latrefrect/rad_to_deg ! radians
-           
-           
+
+
            ! loop over remaining points and add spacing to successive
            ! x locations
            do j = 2, ny_global ! start from j=2. j=1 is latrefrect
@@ -1690,10 +1690,10 @@ subroutine rectgrid_scale_dxdy
                             field_loc_NEcorner, field_type_scalar)
         call ice_HaloExtrapolate(ULAT, distrb_info, &
                                  ew_boundary_type, ns_boundary_type)
-        
+
 
         deallocate(work_g1)
-        
+
       end subroutine rectgrid_scale_dxdy
 
 !=======================================================================
diff --git a/cicecore/drivers/direct/hadgem3/CICE_InitMod.F90 b/cicecore/drivers/direct/hadgem3/CICE_InitMod.F90
index cd27f296e..85050d8c9 100644
--- a/cicecore/drivers/direct/hadgem3/CICE_InitMod.F90
+++ b/cicecore/drivers/direct/hadgem3/CICE_InitMod.F90
@@ -122,7 +122,7 @@ subroutine cice_init
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/drivers/direct/nemo_concepts/CICE_InitMod.F90 b/cicecore/drivers/direct/nemo_concepts/CICE_InitMod.F90
index cd27f296e..85050d8c9 100644
--- a/cicecore/drivers/direct/nemo_concepts/CICE_InitMod.F90
+++ b/cicecore/drivers/direct/nemo_concepts/CICE_InitMod.F90
@@ -122,7 +122,7 @@ subroutine cice_init
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/drivers/mct/cesm1/CICE_InitMod.F90 b/cicecore/drivers/mct/cesm1/CICE_InitMod.F90
index 5ee070673..5efa18a28 100644
--- a/cicecore/drivers/mct/cesm1/CICE_InitMod.F90
+++ b/cicecore/drivers/mct/cesm1/CICE_InitMod.F90
@@ -135,7 +135,7 @@ subroutine cice_init(mpicom_ice)
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/drivers/nuopc/cmeps/ice_comp_nuopc.F90 b/cicecore/drivers/nuopc/cmeps/ice_comp_nuopc.F90
index afdee5590..5f2995132 100644
--- a/cicecore/drivers/nuopc/cmeps/ice_comp_nuopc.F90
+++ b/cicecore/drivers/nuopc/cmeps/ice_comp_nuopc.F90
@@ -576,7 +576,7 @@ subroutine InitializeAdvertise(gcomp, importState, exportState, clock, rc)
     call t_startf ('cice_init1')
     call cice_init1
     call t_stopf ('cice_init1')
-    
+
     !-----------------------------------------------------------------
     ! Advertise fields
     !-----------------------------------------------------------------
diff --git a/cicecore/drivers/nuopc/dmi/CICE_InitMod.F90 b/cicecore/drivers/nuopc/dmi/CICE_InitMod.F90
index 02356e2ba..dc83c7703 100644
--- a/cicecore/drivers/nuopc/dmi/CICE_InitMod.F90
+++ b/cicecore/drivers/nuopc/dmi/CICE_InitMod.F90
@@ -144,7 +144,7 @@ subroutine cice_init(mpi_comm)
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/drivers/standalone/cice/CICE_InitMod.F90 b/cicecore/drivers/standalone/cice/CICE_InitMod.F90
index c91dae4b4..8de05a121 100644
--- a/cicecore/drivers/standalone/cice/CICE_InitMod.F90
+++ b/cicecore/drivers/standalone/cice/CICE_InitMod.F90
@@ -132,7 +132,7 @@ subroutine cice_init
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/drivers/unittest/gridavgchk/CICE_InitMod.F90 b/cicecore/drivers/unittest/gridavgchk/CICE_InitMod.F90
index c65f04150..9ed1c5cbc 100644
--- a/cicecore/drivers/unittest/gridavgchk/CICE_InitMod.F90
+++ b/cicecore/drivers/unittest/gridavgchk/CICE_InitMod.F90
@@ -123,7 +123,7 @@ subroutine cice_init
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/drivers/unittest/sumchk/CICE_InitMod.F90 b/cicecore/drivers/unittest/sumchk/CICE_InitMod.F90
index f0877d502..8a5070d25 100644
--- a/cicecore/drivers/unittest/sumchk/CICE_InitMod.F90
+++ b/cicecore/drivers/unittest/sumchk/CICE_InitMod.F90
@@ -124,7 +124,7 @@ subroutine cice_init
       call init_calendar        ! initialize some calendar stuff
       call init_hist (dt)       ! initialize output history file
 
-      if (kdyn == 1) then 
+      if (kdyn == 1) then
          call init_evp
       else if (kdyn == 2) then
          call init_eap          ! define eap dynamics parameters, variables
diff --git a/cicecore/version.txt b/cicecore/version.txt
index 154cda3d7..953395fa1 100644
--- a/cicecore/version.txt
+++ b/cicecore/version.txt
@@ -1 +1 @@
-CICE 6.4.0
+CICE 6.4.1
diff --git a/doc/source/conf.py b/doc/source/conf.py
index a1b2871ae..88b98bc09 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -62,9 +62,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'6.4.0' 
+version = u'6.4.1' 
 # The full version, including alpha/beta/rc tags.
-version = u'6.4.0' 
+version = u'6.4.1' 
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/icepack b/icepack
index 8637a2d28..8f96707a9 160000
--- a/icepack
+++ b/icepack
@@ -1 +1 @@
-Subproject commit 8637a2d287f078c267f7912753919e54f188c434
+Subproject commit 8f96707a90132ca119d81ed84e5a62ca0ff3ed96