Early Results from AIRS and Risk Reduction Benefits for other

Advanced Infrared Sounders

Mitchell D. GoldbergNOAA/NESDIS

Center for Satellite Applications and ResearchSatellite Meteorology and Climatology

DivisionOctober 2, 2002GOES-R User Conference

BackgroundBackground Atmospheric Infrared Sounder (AIRS) was Atmospheric Infrared Sounder (AIRS) was

launched on the AQUA satellite on May 4, 2002 - launched on the AQUA satellite on May 4, 2002 - Polar orbit 705 km, 13:30 ECTPolar orbit 705 km, 13:30 ECT

AIRS – high spectral resolution infrared sounder AIRS – high spectral resolution infrared sounder and will greatly improve the accuracy of and will greatly improve the accuracy of temperature and moisture soundings.temperature and moisture soundings.

NOAA/NESDIS is processing and distributing NOAA/NESDIS is processing and distributing AIRS data and products in near real-time to AIRS data and products in near real-time to operational NWP centers.operational NWP centers.

This project is supported by: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 NPP Program, and Joint Center for Satellite Data

AssimilationAssimilation

So why is AIRS So why is AIRS important for GOES-R?important for GOES-R?

Currently the only high spectral resolution infrared Currently the only high spectral resolution infrared sounder with good spatial coveragesounder with good spatial coverage

Provide risk reduction for:Provide risk reduction for:

- new science applications- new science applications

- processing systems for data distribution and - processing systems for data distribution and utilization utilization

No other substitute prior to GIFTSNo other substitute prior to GIFTS

AIRS IR InstrumentAIRS 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 Spectral coverage 3.7 to 15.4 microns in 17 arrays with

2378 spectral channels (2378 spectral channels (3.74-4.61 µm, 6.2-8.22 µm,3.74-4.61 µm, 6.2-8.22 µm,8.8-15.4 µm)8.8-15.4 µm)

• Spectral resolution Spectral resolution //=1200, 14 km FOV from 705km =1200, 14 km FOV from 705km orbitorbit

• Launch – May 2002Launch – May 2002• Primary products: temperature profile (< 1 K accuracy), Primary products: temperature profile (< 1 K accuracy),

moisture profile (< 15%) , ozone (< 15 % (layers) and 3 % moisture profile (< 15%) , ozone (< 15 % (layers) and 3 % total)total)

• Research products: CO2, CO, CH4Research products: CO2, CO, CH4• The integrated sounder system includes the AIRS VIS/NIR The integrated sounder system includes the AIRS VIS/NIR

channels and microwave sounderschannels and microwave sounders

AIRS VIS/NIR ChannelsAIRS VIS/NIR Channels

Channel 1 (0.40 – 0.44 um) - aerosolsChannel 1 (0.40 – 0.44 um) - aerosols Channel 2 (0.58 – 0.68 um) - (AVHRR ch. 1)Channel 2 (0.58 – 0.68 um) - (AVHRR ch. 1) Channel 3 (0.71 – 0.93 um) - (AVHRR ch. 2)Channel 3 (0.71 – 0.93 um) - (AVHRR ch. 2) Channel 4 (0.48- 0.95 um) - broadbandChannel 4 (0.48- 0.95 um) - broadband

Microwave SoundersMicrowave Sounders

15 channel AMSU sounder15 channel AMSU sounder 4 channel Humidity Sounder Brazil (HSB)4 channel Humidity Sounder Brazil (HSB) (150 GHz, 183 +- 1, 183 +- 3. 183+-7)(150 GHz, 183 +- 1, 183 +- 3. 183+-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 AIRSVis Channels

14 km fovIR channels AIRS& HSB

42 km fov AMSU

Excellent Noise PerformanceExcellent Noise Performance

PREFLIGHT SPECTRAL CAL SHOWS PREFLIGHT SPECTRAL CAL SHOWS EXCELLENT SPECTRAL SHAPE AND EXCELLENT SPECTRAL SHAPE AND

STABILITYSTABILITY

Knowledge of CentroidsWithin Spec Limits

SRF Shape WellCharacterized to <10-3

Temperature Dependence Well Behaved

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

RISK REDUCTION RISK REDUCTION ACTIVITIES AT NESDISACTIVITIES AT NESDIS

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.

AIRS for NWP has been AIRS for NWP has been very successful very successful

Engaged the user community earlyEngaged the user community early

Defined datasets and formats (BUFR)Defined datasets and formats (BUFR)

Simulated processing and distribution of data Simulated processing and distribution of data in near real-time for two years prior to launchin near real-time for two years prior to launch

NWP Users

• NCEP

• ECMWF

• Met. Office

• Meteo-France

• Goddard DAO

• Meteor. Service of Canada

• Bureau of Meteorology Research Centre (Australia)

• FNMOC

Data Volume Data Volume ChallengesChallenges

AIRS is only 1.5 mbits /secAIRS is only 1.5 mbits /sec

Level 1b radiances is 35 GB per dayLevel 1b radiances is 35 GB per day (current sounder data ~ 70 MB/day)(current sounder data ~ 70 MB/day)

Challenges: 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 Longer term solutions (1-3 years) are to increase communication bandwidth and computer powerbandwidth and computer power

Short term solutions are:Short term solutions are: a) subsample the AIRS spectrally and spatiallya) subsample the AIRS spectrally and spatially b) compress the full spectrum using principle component analysisb) compress the full spectrum using principle component analysis

Early Results from AIRSEarly Results from AIRS

Simulated AIRS Real AIRS

Trace Eigenvalue: real 577096 , simulation 774893

LOG

649.48 cm-1

2616 cm-1

Noise reduction feature is very promisingNoise reduction feature is very promising

Provide reconstructed brightness Provide reconstructed brightness temperatures to NWP centers for evaluation. temperatures to NWP centers for evaluation.

N=5053

8

8

SummarySummary

AIRS will keep us busy for yearsAIRS will keep us busy for years

Lessons learned from AIRS will provide risk Lessons learned from AIRS will provide risk reduction benefits to all high-spectral reduction benefits to all high-spectral resolution sounder programsresolution sounder programs

High spectral resolution infrared data will High spectral resolution infrared data will significantly improve water vapor.significantly improve water vapor.

225 mbAVN

ECMWF