1. Early Results from AIRS and Risk Reduction Benefits for other Advanced Infrared Sounders Mitchell D. Goldberg NOAA/NESDIS Center for Satellite Applications and Research Satellite Meteorology and Climatology Division October 2, 2002 GOES-R User Conference

2. Background  Atmospheric Infrared Sounder (AIRS) was launched on the AQUA satellite on May 4, 2002 - Polar orbit 705 km, 13:30 ECT  AIRS – high spectral resolution infrared sounder and will greatly improve the accuracy of temperature and moisture soundings.  NOAA/NESDIS is processing and distributing AIRS data and products in near real-time to operational NWP centers.  This project is supported by: - AIRS science team, NASA, JPL, IPO, - AIRS science team, NASA, JPL, IPO, NPP Program, and Joint Center for Satellite Data Assimilation NPP Program, and Joint Center for Satellite Data Assimilation

3. So why is AIRS important for GOES-R?  Currently the only high spectral resolution infrared sounder with good spatial coverage  Provide risk reduction for: - new science applications - processing systems for data distribution and utilization - processing systems for data distribution and utilization  No other substitute prior to GIFTS

4. AIRS IR Instrument AIRS is a cooled grating array spectrometerAIRS is a cooled grating array spectrometer Spectral coverage 3.7 to 15.4 microns in 17 arrays with 2378 spectral channels ( 3.74-4.61 µm, 6.2-8.22 µm, 8.8-15.4 µm)Spectral coverage 3.7 to 15.4 microns in 17 arrays with 2378 spectral channels ( 3.74-4.61 µm, 6.2-8.22 µm, 8.8-15.4 µm) Spectral resolution  /  =1200, 14 km FOV from 705km orbitSpectral resolution  /  =1200, 14 km FOV from 705km orbit Launch – May 2002Launch – May 2002 Primary products: temperature profile (< 1 K accuracy), moisture profile (< 15%), ozone (< 15 % (layers) and 3 % total)Primary products: temperature profile (< 1 K accuracy), moisture profile (< 15%), ozone (< 15 % (layers) and 3 % total) Research products: CO2, CO, CH4Research products: CO2, CO, CH4 The integrated sounder system includes the AIRS VIS/NIR channels and microwave soundersThe integrated sounder system includes the AIRS VIS/NIR channels and microwave sounders

5. AIRS VIS/NIR Channels  Channel 1 (0.40 – 0.44 um) - aerosols  Channel 2 (0.58 – 0.68 um) - (AVHRR ch. 1)  Channel 3 (0.71 – 0.93 um) - (AVHRR ch. 2)  Channel 4 (0.48- 0.95 um) - broadband

6. Microwave Sounders  15 channel AMSU sounder  4 channel Humidity Sounder Brazil (HSB) (150 GHz, 183 +- 1, 183 +- 3. 183+-7) (150 GHz, 183 +- 1, 183 +- 3. 183+-7)

7. NOTE: Pixel size ~ 2.28 km for Vis, Beam diameter 1.1° for AIRS &HSB & 3.3° for AMSU A AIRS-AMSU-HSB Schematic of Ground Location 2x2 km fov AIRS Vis Channels 14 km fov IR channels AIRS & HSB 42 km fov AMSU

8. Excellent Noise Performance

9. PREFLIGHT SPECTRAL CAL SHOWS EXCELLENT SPECTRAL SHAPE AND STABILITY Knowledge of Centroids Within Spec Limits SRF Shape Well Characterized to <10 -3 Temperature Dependence Well Behaved

10. Analysis by L. Strow of UCMB AIRS Bias Spectrum for Cloud-Free FOVs in 3 Granules on July/20/02 Computed Spectrum Uses kCARTA and NWP Analysis Field

11. RISK REDUCTION ACTIVITIES AT NESDIS

12. Near real-time distribution and utilization of AIRS for NWP data assimilation Goals: Provide AIRS/AMSU/HSB data and products to NWP centers in near real-time --- generally 3 hours from observation time. Demonstrate positive impact in NWP. Demonstrate processing and utilization of high spectral resolution infrared data in preparation for CrIS, IASI and GOES-R. Demonstrate EDR performance.

13. AIRS for NWP has been very successful  Engaged the user community early  Defined datasets and formats (BUFR)  Simulated processing and distribution of data in near real-time for two years prior to launch

14. NWP Users NCEP ECMWF Met. Office Meteo-France Goddard DAO Meteor. Service of Canada Bureau of Meteorology Research Centre (Australia) FNMOC

15. Data Volume Challenges  AIRS is only 1.5 mbits /sec  Level 1b radiances is 35 GB per day (current sounder data ~ 70 MB/day) (current sounder data ~ 70 MB/day)  Challenges: - getting the data to the users - getting the data to the users - assimilating the data - assimilating the data  Longer term solutions (1-3 years) are to increase communication bandwidth and computer power  Short term solutions are: a) subsample the AIRS spectrally and spatially a) subsample the AIRS spectrally and spatially b) compress the full spectrum using principle component analysis b) compress the full spectrum using principle component analysis

17. Early Results from AIRS

18. Simulated AIRS Real AIRS

19. Trace Eigenvalue: real 577096, simulation 774893 LOG

20. 649.48 cm-1

21. 2616 cm-1

23.  Noise reduction feature is very promising  Provide reconstructed brightness temperatures to NWP centers for evaluation.

26. N=5053 8

27. 8

28. Summary  AIRS will keep us busy for years  Lessons learned from AIRS will provide risk reduction benefits to all high-spectral resolution sounder programs  High spectral resolution infrared data will significantly improve water vapor.

29. 225 mb AVN ECMWF