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Revision of the ATOVS/AMSU-A, AMSU-B, MHS channel selection for DA

Revision of the ATOVS/AMSU-A, AMSU-B, MHS channel selection for DA Roger Randriamampianina and Benedikt Strajnar. How to perform the experiments. Impact of the bias correction. How to perform the experiments. - First of all one need to have precomputed first guesses.

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Revision of the ATOVS/AMSU-A, AMSU-B, MHS channel selection for DA

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  1. Revision of the ATOVS/AMSU-A, AMSU-B, MHS channel selection for DA Roger Randriamampianina and Benedikt Strajnar

  2. How to perform the experiments • Impact of the bias correction

  3. How 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 !

  4. How to check the necessary information for monitoring • Example of odb request: • cat >myview.sql <<EOF • SELECT • obstype,statid, varno,press_rl,sensor,fov@atovs, an_depar, fg_depar, obsvalue, biasctrl, predictor[1]@atovs_pred • FROM hdr,desc,body,atovs,atovs_pred • WHERE ((varno /= 91 ) AND (an_depar is not NULL)) • EOF • Where: • fg_depar- bias corrected O-B • an_depar- O-A • biasctrl - the applied bias correction •  To have the uncorrected O-B = fg_depar + biasctrl

  5. One can plot the corrected and non-corrected departures Dashed line: uncorrected departure Bold: analysis bias Solid line: first-guess bias Lower plot: number of active obs

  6. 24h update 6h update

  7. Impact of the bias correction scheme

  8. Results of the recent Hungarian monitoring AMSU-A

  9. Results of the recent Hungarian monitoring AMSU-B / MHS

  10. Need longer period?

  11. Bad channel

  12. Bad channel

  13. I would say no in this case

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