February 25, 2003syl

1Level 2 Status

Level 2 Status

Sung-Yung Lee and Edward Olsen

Chris Barnet and John Blaisdell

February 25, 2003

February 25, 2003syl

2Level 2 Status

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

February 25, 2003syl

3Level 2 Status

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

February 25, 2003syl

4Level 2 Status

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

February 25, 2003syl

5Level 2 Status

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

February 25, 2003syl

6Level 2 Status

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 -9999.

• All other bits diagnose situations which are usually harmless.

• Recommendation is to ignore the QA flags, but check the radiances for -9999.

February 25, 2003syl

7Level 2 Status

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/

February 25, 2003syl

8Level 2 Status

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 2.7.12, with regression.

February 25, 2003syl

9Level 2 Status

Global ECMWF Comparison

• Ocean cases• abs(lat) < 40• zen angle < 40

• Black curve is bias• Blue curve is RMS

difference

• Regression will improve statistics

February 25, 2003syl

10Level 2 Status

Browse ProductsTotal Precipitable Water Vapor

February 25, 2003syl

11Level 2 Status

Browse ProductsSurface Skin Temperature

February 25, 2003syl

12Level 2 Status

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