# Presentation: 413867

## Level 2 Status

- Sung-Yung Lee and Edward Olsen
- Chris Barnet and John Blaisdell
- February 25, 2003

- May 22, 2000

## 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

- May 22, 2000

## 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

- May 22, 2000

## 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

- May 22, 2000

## 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

- May 22, 2000

## 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.

- May 22, 2000

## 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/

- May 22, 2000

## 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.

- May 22, 2000

## Global ECMWF Comparison

- Ocean cases
- abs(lat) < 40
- zen angle < 40
- Black curve is bias
- Blue curve is RMS difference
- Regression will improve statistics

- May 22, 2000

## Browse ProductsTotal Precipitable Water Vapor

- May 22, 2000

## Browse ProductsSurface Skin Temperature

- May 22, 2000

## 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

- May 22, 2000