Revision of the ATOVS/AMSU-A, AMSU-B, MHS channel selection for DA
Roger Randriamampianina and Benedikt Strajnar
Impact of the bias correctionImpact of the bias correction
How to perform the experimentsHow to perform the experiments
How to perform the experimentsHow to perform the experiments
- First of all one need to have precomputed first guesses
- Use these guesses to do series of passive analyses means do screening and minimization without 6h forecast
- Normally, one-month period is enough to check the functionality of the applied bias correction scheme.
- Before starting the series of passive analyses, it is recommended to change the blacklisting rules to have as much as possible active observation, or at least passive observations during the minimization. this means empty the file LISTE_LOC, and change the rules in the file mf_blacklist.b and recopile your pack to have new executable. NOTE: this executable is meant for the monitoring purpose ONLY and not suitable for any assimilation study !
How to check the necessary information for monitoringHow to check the necessary information for monitoring
-Example of odb request:
cat >myview.sql <<EOFSELECTobstype,statid, varno, press_rl, sensor, fov@atovs, an_depar, fg_depar, obsvalue, biasctrl, predictor[1]@atovs_predFROM hdr,desc,body,atovs,atovs_predWHERE ((varno /= 91 ) AND (an_depar is not NULL))EOF
Where:fg_depar- bias corrected O-Ban_depar- O-Abiasctrl - the applied bias correction To have the uncorrected O-B = fg_depar + biasctrl
One can plot the corrected and non-corrected departuresOne can plot the corrected and non-corrected departures
Dashed line: uncorrected departureBold: analysis biasSolid line: first-guess biasLower plot: number of active obs
24h update 6h update
Impact of the bias correction scheme
00 UTC 06 UTC 12 UTC 18 UTC
NOAA-16 -- 5-8(?), 9-12, 13(?)
-- 5-8(?), 9-11, 12(?), 13(?)
NOAA-18 5-11,
12(?),13(?)
-- 5-6(lp?), 7, 8(no), 9-12,
13(?)
--
NOAA-19 5(?), 6-7, 8(no), 9-12,
13(?)
-- 5-7, 8(no), 9-12, 13 (?)
--
METOP-2 -- 5(lp?), 6(no),7(no),8-12, 13(?)
5-8(lp?), 9-12,
13 (no)
5-8(no), 9-12,
13(?)
Results of the recent Hungarian monitoringResults of the recent Hungarian monitoring
AMSU-A
00 UTC 06 UTC 12 UTC 18 UTC
NOAA-16 -- 5(no),4(?), 3 -- 3-4, 5(no)
NOAA-18 5(no), 3-4 -- 3-4, 5(no) --
NOAA-19 5(no), 3-4 -- 3-4, 5(no) --
METOP-2 -- 3-5 3-4, 5(?) 3-4, 5(?)
AMSU-B / MHS
Results of the recent Hungarian monitoringResults of the recent Hungarian monitoring
Need longer period?
Bad channel
Bad channel
I would say no in this case