Intercomparisons of AIRS and Intercomparisons of AIRS and NAST retrievals with Dropsondes NAST retrievals with Dropsondes

During P-TOSTDuring P-TOST(Pacific Thorpex Observational System Test) (Pacific Thorpex Observational System Test)

NASA ER-2

NOAA G-IVDropsonde

Empirical Orthogonal Function (EOF) Empirical Orthogonal Function (EOF) NAST-I/AIRS Regression RetrievalNAST-I/AIRS Regression Retrieval

nc

1jjiji ERC

PKCK1

1smni

n

imi

τ*Bτ)ε-(1τBτBεR0

,P

,,

,P

P

,,, ddcs

cscs

cs

ac

cscscs

R = radiance

s,c = surface or cloud emissivityBs,c = surface or cloud Planck radiance = transmittance between aircraft and …..atmospheric Pressure level (P)

S,c=atmospheric transmittance between ……aircraft and surface or cloud (PS,c)

* = atmospheric transmittance between ……surface or cloud P and aircraftPac = aircraft pressure, Ps = surface pressure = radiance E = radiance covariance EOFsC = radiance EOF amplitudesT = temperatureQ = H2O mixing ratioK = regression coefficients

• Physical Regression – EOFs and regression training based on calculated radiances

• Training includes cloud, sfc. emissivity, skin temp, and solar variability effects

• Null radiance errors assumed for PC specification and regression training

• EOF # selected by spatial radiance RMSD (observed minus retrieval) minimization

Ts,s() ,T(p),Q(p)

RetrievalSolution

Radiance EOFAmplitudes

For clear sky and opaque cloud:

NAST-I and AIRS Spectra and Retrieval ChannelsNAST-I and AIRS Spectra and Retrieval Channels

Aqua Overpass Flight (March 3, 2003)Aqua Overpass Flight (March 3, 2003)

AIRS NAST

AIRS and NAST Date Used for IntercomparisonAIRS and NAST Date Used for Intercomparison

Some Differences in fine scale structure but spatial average is in good agreement

Retrieval ComparisonsRetrieval Comparisons (Full Resolution AIRS vs NAST)(Full Resolution AIRS vs NAST)

NAST

Dropsonde

3 x 3 AIRS Average Vs NAST & Dropsonde Cross-sections3 x 3 AIRS Average Vs NAST & Dropsonde Cross-sections

@ AIRS resolution

Dropsonde

Dropsonde

Dropsonde

Above NOAA G-IV Altitude

150 km

3 x 3 Average

3 x 3 AIRS Average Vs NAST & Dropsonde Cross-sections3 x 3 AIRS Average Vs NAST & Dropsonde Cross-sections

@ AIRS resolution

Dropsonde

Dropsonde

Dropsonde

Above NOAA G-IV Altitude

150 km

3 x 3 Average

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Aqua Overpass Flight (March 11/12, 2003)Aqua Overpass Flight (March 11/12, 2003)

Surface/Cloud Temperature (March 11/12, 2003)Surface/Cloud Temperature (March 11/12, 2003)

AIRS NAST

Temperature (March 11/12, 2003)Temperature (March 11/12, 2003)

NAST

Dropsonde

Cloud top

Temperature Deviation (March 11/12, 2003)Temperature Deviation (March 11/12, 2003)

Temperature Deviation (March 11/12, 2003)Temperature Deviation (March 11/12, 2003)

Clouds

Clouds

Clouds

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Relative Humidity (March 11/12, 2003)Relative Humidity (March 11/12, 2003)

Above NOAA G-IV Altitude

Relative Humidity (March 11/12, 2003)Relative Humidity (March 11/12, 2003)

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Clouds

Clouds

Clouds

Temperature (March 11/12, 2003)Temperature (March 11/12, 2003)

Relative Humidity (March 11/12, 2003)Relative Humidity (March 11/12, 2003)

Aqua Overpass Flight (March 12/13, 2003)Aqua Overpass Flight (March 12/13, 2003)

AQUATrack

AIRS and Dropsonde Data Used for IntercomparisonAIRS and Dropsonde Data Used for Intercomparison

Su

rface/ Ef fect ive C

loud T

emp era tu

re (K)

AIRS Soundings Used for Cross-section

DropsondeLocations

Retrieval ComparisonsRetrieval Comparisons (Deviation from the Mean)(Deviation from the Mean)

1500 km

Dropsonde Mean

Retrieval ComparisonsRetrieval Comparisons (Deviation from the Mean)(Deviation from the Mean)

1500 km

Dropsonde Mean

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Above NOAA G-IV Altitude

Retrieval ComparisonsRetrieval Comparisons (Deviation from the Mean)(Deviation from the Mean)

G-4

G-4

1500 km

Summary and Future Validation OpportunitiesSummary and Future Validation Opportunities

•Aqua satellite AIRS and aircraft NAST-I Aqua satellite AIRS and aircraft NAST-I thermodynamic profiles agree well with each other thermodynamic profiles agree well with each other and with in-situ dropsonde measurements. The and with in-situ dropsonde measurements. The vertical resolution of AIRS appear to be as vertical resolution of AIRS appear to be as advertised advertised (i.e., 1-3 km, depending upon altitude).(i.e., 1-3 km, depending upon altitude).

• Next AIRS NAST/SHIS/MAS/CPL/Dropsonde Next AIRS NAST/SHIS/MAS/CPL/Dropsonde validation opportunity is Atlantic Thorpex validation opportunity is Atlantic Thorpex Observational Systems Test (ATOST)- Observational Systems Test (ATOST)- 15 15 Nov. – 15 Dec. 2002 (Bangor, MA)Nov. – 15 Dec. 2002 (Bangor, MA)

• July 2004 Opportunity: Multi-agency chemistry and July 2004 Opportunity: Multi-agency chemistry and

air quality measurement program (NE US)air quality measurement program (NE US)