Version 9 (modified by 3 years ago) (diff) | ,
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Impact Of a Single Observation from IASI
Aim
This test is a part of the H-8 AHI trial. As the weighting functions of IASI channels peak sharply the analysis increments can be better understood.
Experimental Set-up
Following set of configurations were used for this test,
- 3DVAR
- non-hybrid and no ensemble cycles
- Resolution of PFM is N108
- no VarBC
Note 1. N108 PFM resolution differs from the screen 3DVAR resolution
Experiment was done using suite ID u-am568 (copy of u-aj730/trunk@40220). I made following modifications to progressively arrive at the target configuration outlined above,
- ensemble and hybrid VAR are switched off (job #1)
- turned off VarBC (job #2)
- copied screen 3DVAR app config file then made following changes
- point to locations of LS, varobs and varcx
- turned on 3DVAR - it appears all observations supplied are used, so this is FGAT 3DVAR (job #3)
- following the changes in u-aj977 Ops_ExtractAndProcess for AHI CSR selected smaller number of IASI observations
- turned on SatRad NetCDF write
- then a single FOV was selected using extractcontrolnl: this passed QC and thinning and was the only FOVS in varobs; 83.77021 degE, -28.4431 degN
- following the changes in u-aj977 Var_AnalysePF only assimilated IASI
ToDo
- Under [namelist:var_minimisenl] of gl_var_anal_low app maxiterations is 20. Perhpas this needs to be increased to 40 as in 4DVAR (?)