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NOAA-EMC / JEDI-T2O

JEDI Transition to Operations activities.
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AMSU-A 3D H(x) Evaluation #31

Open CoryMartin-NOAA opened 2 years ago

CoryMartin-NOAA commented 2 years ago

Compare H(x) generated from GSI with H(x) generated by FV3-JEDI in UFO for both unbias corrected and bias corrected radiances for each AMSU-A platform and channel.

CoryMartin-NOAA commented 2 years ago

Screenshot from 2022-07-05 20-01-43 Screenshot from 2022-07-05 19-57-38 Screenshot from 2022-07-05 19-56-53 The screenshots are for NOAA-15 but should apply to all observation types. These are the differences in GSI H(x) after changing prsi to be computed from delp rather than ps * bk + ak. There is a pretty consistent bias that is shown when the colorbar is +-0.1K. It is Old - New, and the H(x) difference is positive. This suggests that there is an impact in the pressure computation difference. Also note, the relatively huge differences in S. America due to topography.

CoryMartin-NOAA commented 2 years ago

@ADCollard and I have been trying to figure out this problem for a while:

Image

cmp was executed on the amsua_n19.TauCoeff.bin file that comes with JEDI and the version that existed already on Orion for CRTM 2.3.0:

amsua_n19.TauCoeff.bin /work/noaa/global/glopara/crtm/crtm_v2.3.0/TauCoeff/ODPS/Little_Endian/amsua_n19.TauCoeff.bin differ: byte 17, line 1

Copying the TauCoeff.bin file to /work2/noaa/da/cmartin/GDASApp/fix/crtm/2.3.0_jedi and rerunning produces this:

Image

So it seems the CRTM coefficient files provided by JEDI cannot be trusted and we need to use our own CRTM 2.3 little endian coefficient files.