Linear operator for clear sky MW inconsistent w/ GSI's

[rtodling]

I am working to add T-skin as a CV to JEDI just as it is in GSI. All works now and an initial attempt reveals that the MW operator in JEDI does not process the sensitivity to skin (land) temperature the same way as GSI's.

Here is a plot of the comparison (w/ a multiplier factor of 2 for visual enhancement: as usual GSI (top) JEDI(bot). This is a case when only ATMS-N20 observations are used in both systems.

Notice also the increment over Antartica that is not present in JEDI's.

[rtodling]

I believe the above is associated with the settings in the linear operator of MW (clear sky) that presently read:

      Surfaces:
      - Water_Temperature

I believe the consistent settings would be something like:

      Surfaces:
      - Water_Temperature
      - Land_Temperature
      - Ice_Temperature
      - Snow_Temperature

[rtodling]

Just to provide a piecemeal illustration here is what happens w/ the comparison when Land_Temperature (only) is added to the present settings - so that JEDI uses:

Surfaces:
- Water_Temperature
- Land_Temperature

Now the land impact shows up in JEDI's increment ... but we still miss the Antartica increment.

[rtodling]

Now interestingly, when all four surfaces (Water, Land, Ice, and Snow) are passed to the linear observation operator, there are still no increments over Antartica ... the reason for this might be a missing sensitivity in UFO ... will look.