# Presentation: 809844

## Status of Version 3.5 AIRS Science Team MeetingGreenbelt, Maryland March 29, 2004

- Sung-Yung Lee
- Thomas Hearty
- Evan Manning

- May 22, 2000

## Summary

- Version 4.0 development schedule is very tight.
- Retrievals over non-frozen land
- Version 3.5 is almost ready for delivery to NOAA/NRT.
- Acceptable outlier rate with decent yield.
- Discontinuity on January 10, 2003
- Caused by a channel that was marked bad (ABstate of 3) during Janaury 10 to November 19, 2003 time period
- Couple of bugs were discovered during the debugging process
- Level 2 works fine on the data after November 19, 2003
- Some of the data already processed are affected
- Jan 10 - 31, 2003
- Focus days in July, August and October 2003

- May 22, 2000

## Version 4.0 Plan

- REALLY TIGHT Schedule
- New Requirement (NR), most of Change Request (CR) by June 1, 2004
- Development cycle ends July 1, 2004
- Simplest CR and Anomaly Reports (AR) can be made by end of July 21, 2004
- Last build for validation runs by early August
- Critical Items for V4.0
- New RTA
- Should be finished by early June, earlier the better
- Decent retrievals over non-polar land
- Clear flag over land?
- Cloud/OLR retrievals for retrieval type 100
- New set of coefficients (tuning, local angle correction and regression)

- May 22, 2000

## Version 3.5 Status

- All data processing is finished with V3.5.0
- Mini-validation (12 focus days, 3 months of fixed matchups, buoy matchups for 12 focus days)
- January 2003 for GMAO
- New Build, V3.5.1, is being tested
- All minor impact to retrievals/radiances
- Test on a focus day to verify
- Geolocation fix for level 1a PGE
- CO output for rejected retrievals
- Cloud liquid water error estimate bug fix
- NOAA/NRT delivery is expected in mid April

- May 22, 2000

## Yields and Outlier Statistics

- 12 Focus days
- Generally 48 days apart
- September 6 2002 to December 5 2003
- ~30% yields over ocean between 50S and 50N
- Worst is Jan 3/4 2003
- < 1% outlier rate
- Worst is July 2003

- May 22, 2000

## Yield and Outlier Statistics for V3.5By MW Surface Class

|  | Combined | Ascending | Descending |
| --- | --- | --- | --- |
| Ocean Yield | 29.8 % | 30.3 % | 29.3 % |
| Ocean Outliers | 0.8 % | 0.6 % | 1.1 % |
| Land Yield | 15.0 % | 4.5 % | 24.8 % |
| Coast Yield | 22.0 % | 15.1 % | 29.3 % |
| Other Yield | 17.7 % | 8.3 % | 23.1 % |

- May 22, 2000

## Temperature Statistics for V3.5vs ECMWF Forecast

- 12 Focus days
- Ocean
- Coastline
- Land
- Other (Frozen surfaces)
- Optimized for ocean cases
- MW Surface Class was used.
- Next Step
- Land and Ice

- May 22, 2000

## Surface Skin Temperature Histogramfor September 6, 2002

- Ocean Footprints between 50N and 50S with RetQAFlag
- With RetQAFlag
- Yield = 32.5%
- Outlier = 0.7%
- Bias = -0.42K
- St Dev = 0.87K
- With retrieval type
- Yield = 38.5%
- Outlier = 3.8%
- Bias = -0.58
- St Dev = 1.23

- May 22, 2000

## Retrievals with Retrieval_type 0Version 3.2.7Red dots represent outliers

- May 22, 2000

## Retrievals with Version 3.5 RetTypeRed dots represent outliers

- May 22, 2000

## Retrievals with Version 3.5.0 RetQARed dots represent outliers

- May 22, 2000

## January 10, 2003 Discontinuity

- Discontinuity was first observed in ozone and then skin temperature
- Then it turned out that the land yield dropped on January 10th changing sample characteristics
- The surface regression uses 1072.51 cm-1 channel
- This had AB state of 3 between January 10, 2003 and November 19, 2003
- The AB state was 2 before and after the time period
- Input QA fills all radiances to -9999. when AB state is larger than 2.
- A bug in the input QA makes the test inoperable, but redundant excluded_channel test works unless old version of level 1b is used.
- Surface regression aborts with a single bad radiance without retrieving skin temperature or surface emissivity
- Final retrieval uses MW only skin temperature and unknown spectral emissivity over land/coast.
- Affected data already processed
- January 10 - November 19, 2003
- Focus days July 14, August 31, and Oct 18, 2003
- But focus days in Feb/April/May were run on level 1b files with old excluded channels list and are OK
**The level 2 PGE will work fine with current data/channel property file.**
- Retrievals for March 10, 2004 focus day confirms this

- May 22, 2000

## Yield for Focus Days

- Yield based on retrieval type
- Total (Black)
- Land (Red)
- Water (Blue)

- May 22, 2000

## Yield for January 2003

- Yield based on retrieval type
- Total (Black)
- Land (Red)
- Water (Blue)

- May 22, 2000