Level 2 Status February 25, 2003 syl 1 Level 2 Status Sung-Yung Lee and Edward Olsen Chris Barnet and John Blaisdell February 25, 2003

Level 2 Status February 25, 2003 syl 2 Summary V2.7 Delivered to DAAC –Functioning level 2 –Good yield over ocean surface –Bias only tuning –Coefficient update planned No regression step without coefficient update Convergence of GSFC research version and Team software. –Many minor updates to both software programs –Version 2.8 has all the fixes for convergence –Convergence effort will continue in the background Work on V3.0 starts –AIRS RTA V7 implemented –Regression/Tuning/AngCorr coefficients update –Sidelobe Correction Algorithm delayed –March 11 deadline for software updates Data processing for validation report Bug fixes will continue

Level 2 Status February 25, 2003 syl 3 Team Software for Level 2 Unified Team software –Various Algorithms and software modules are supplied and maintained by science team members –Each team member develops algorithm/software at their home institution and ports the software to the team software. –This causes time lag between research versions and team software. –Unique among EOS instrument teams Roles –JPL team is responsible for data flow, I/O routines, bullet proofing, etc –GSFC team is responsible for cloud clearing, final algorithm –NESDIS members are responsible for regression guess, tuning, angle correction –MIT members are responsible for MW only algorithms including precipitation –UMBC is responsible for RTA

Level 2 Status February 25, 2003 syl 4 PGE V2.7 Retrieval Delivered to DAAC –To go operational in early March –No public release of level 2 data Retrieval software is functioning reasonably well –High quality retrieval for clear ocean cases –Global average yield of ~60% over ocean New option to use GSFC tuning in brightness temperature Regression Coefficients –Valid over ocean –New version based on cloud cleared radiances is expected soon MW Tuning available –GSFC bias only tuning with respect to ECMWF –NESDIS Tuning with respect to NCEP IR Tuning –GSFC bias only tuning in br temp –NESDIS tuning in radiance unit Bias only tuning works –UMBC bias only tuning

Level 2 Status February 25, 2003 syl 5 Status of Convergence Convergence is essentially achieved in V2.8 –Subtle bugs were found and fixed both at JPL and GSFC –Missed updates were completed on both sides –Choices in processing were made more equal –Lingering small differences still to be checked as time permits Would have been impossible to find these things without offline GSFC system for comparison. One remaining issue –use of quality flags to determine which channels to use in processing (what is bad?) Must repeat convergence with V3.0 build to check updates and test additional conditions

Level 2 Status February 25, 2003 syl 6 QA Flags for MW instruments Team software does not check the MW QA flags –QA_scanline –QA_reciever_a11 –QA_channel Currently 7th bit (noisy bit) is turned on few times a granule All of the fields that denote serious problems will cause BTs to be set to All other bits diagnose situations which are usually harmless. Recommendation is to ignore the QA flags, but check the radiances for

Level 2 Status February 25, 2003 syl 7 Level 2 PGE Version 2.8 Version 2.7 with convergence fixes Intermediate version for validation exercise –Preview of the main validation run scheduled for mid-March Reports at this team meeting are based on this run –3 days (Sept 6, Sept 29, Nov 16) of normal retrieval –Matchup retrievals for Ra Obs, Fixed sites, and SurfMarine Sept 6, Sept 26 - Oct 2, Nov 16 –In /archive/AIRSOps/test/ValRun1/

Level 2 Status February 25, 2003 syl 8 Retrieval Statistics vs ECMWF RMS difference to ECMWF forecast Granule 50 of Sept 6, a night granule over tropical Atlantic Blue Curve 76 Clear Cases (HHA) Black Curve All cases (~1200) Version , with regression.

Level 2 Status February 25, 2003 syl 9 Global ECMWF Comparison Ocean cases abs(lat) < 40 zen angle < 40 Black curve is bias Blue curve is RMS difference Regression will improve statistics

Level 2 Status February 25, 2003 syl 10 Browse Products Total Precipitable Water Vapor

Level 2 Status February 25, 2003 syl 11 Browse Products Surface Skin Temperature

Level 2 Status February 25, 2003 syl 12 Plan for V3.0 Converged software is the starting point Scheduled delivery of May, 2003 First build of v3.0 will be during the second week of March –Validation report will be based on this build –Bug fixes continue Validation of this version will focus on near nadir ocean cases AIRS RTA version 7 –Tuning, angle correction need new coefficients Use MW antenna temperature instead of brightness temperature –Sidelobe correction delayed until 3.x New tuning algorithm expected from McMillin New Regression algorithm expected from Goldberg UARS Climatology update - fix water/ozone profile