UFO Evaluation for Scatwind -- re-evaluation for new changes from GMAO

[emilyhcliu]

There are several UFO updates from GMAO regarding winds.
This PR is to test the updates from GMAO for Scatterometer Winds

Here is the collection of related UFO PRs PR #3061 PR #3050 PR #3026

Notes for Input Test Data:

• The test input data for winds must also be updated since we need to save the original fact10 (data(iff10,i))calculation from the fv3, not the fact10 modified by GSI (factw) based on lower model height (related GSI code section)

• add slmsk (related to idomsfc and isflg used in GSI), water_area_fraction, land_area_fraction, ice_area_fraction, snow_area_fraction

  Notes: Check GeoVaLs: slmsk and area_fraction (water, ice, snow, and land) Model: slmsk: 0, 1, 2 (sea, land, ice) GeoVaLs: slmsk: 0, 1, 2, 3, 4, 5 (model slmsk + 3 ---> 0+3, 1+3, 2+3 ---> 3, 4, 5

  In GSI: for scatwind use idomsfc from deter_sfc2 use iflg from deter_sfc_type

  • idomsfc is determined by ilsi_full and weights (dist between grid points and obs) idomsfc is determined by model slmsk and slmsk+3 idomsfc ranges from 0, 1, 2, 3, 4, 5

  • isflg is deermined by islis_full and weights ---> sfcpct (surface type %) ---> isflg surface type % > 0.99 ---> isflg - surface_type isflg = 0 (sea); 1 (land); 2 (ice); 3 (snow); 4 (mixed)

  There is no isflg in fv3-jedi, so add area_fractions

• add tsavg from deter_sfc_type as surface_temperature in GeoVaLs (need to check fv3-jedi later)

• Set nvqc = .false. (turn off varQC)

• No FGAT

[emilyhcliu]

Original HofX Configuration

 obs operator:
   name: VertInterp
-  apply near surface wind scaling: true

• This configuration works when we run Hofx with Obs and GeoVaLs from GSI diagnostics since pressure at the obs location is provided through GSI, so we can use interpolation with pressure coordinate
• The fact10 scaling factor is provided through GeoVaLs. The fact10 scaling factor is from model and then modified by GSI
• This configuration won't work when we run HofX from end to end since the observation input data (from BUFR) does not have the pressure information at obs location; obs height is provided. Please see the documentation

Modified Hofx Configuration

 obs operator:
      name: VertInterp
      apply near surface wind scaling: true
      vertical coordinate: geometric_height
      observation vertical coordinate: height

• This configuration work in end-to-end test. Please see the documentation
• However, this configuration has one problem: the surface wind scaling is provided from the model and then further modified by GSI under some conditions. The modified surface wind scaling factor was not implemented in UFO. The GMAO PR provided the calculation of the modified factor.

[emilyhcliu]

Here is the updated configuration:

obs operator:
  name: VertInterp
  # Use height vertical coordinate first
  vertical coordinate: geopotential_height
  observation vertical coordinate group: DerivedVariables
  observation vertical coordinate: adjustedHeight
  interpolation method: linear
  hofx scaling field: SurfaceWindScalingHeight
  hofx scaling field group: DerivedVariables

The wind scaling factor is calculated through the UFO variable transform:

  # Apply variable changes needed for rescaled height coordinate
  - filter: Variable Transforms
    Transform: AdjustedHeightCoordinate

  # Apply variable changes needed for wind scaling
  - filter: Variable Transforms
    Transform: SurfaceWindScalingHeight

[emilyhcliu]

HofX Results:

The larger HofX difference over cold surface area results from using geopotential_height as reference coordinate. The geometric_height should be used (following GSI) Please see the documentation

[emilyhcliu]

HofX Results --- using geometric_height

There are still some outliers in the cold surface area after using the geometric_height. Our previous assessment does not see these outliers. Please see the documentation

There are minor bugs in calculating the surface wind scaling factor in the variable transform. The difference between GSI and UFO are small, though....

[emilyhcliu]

Next is to invesgate the HofX + QC with changes from GMAO

[emilyhcliu]

HofX Comparison with GSI

QC Comparison with GSI

Obs Error Comparion with GSI