1. Tony Clough, Mark Shephard and Jennifer Delamere Atmospheric & Environmental Research, Inc. Colleagues University of Wisconsin International Radiation Symposium Busan, Korea August 2004 Spectroscopic Issues Associated with Atmospheric Remote Sensing

2. Evaluation of CCM3 with HIRS Radiances Iacono et al., JGR 2003 Cloud Cleared: Bates Channel 4: Temperature Field Channel 12: Water Vapor Field

5. Remote Sensing of Ozone Ozone Sonde Issues (Spatial, Temporal, Accuracy) extremely valuable Ozone Spectroscopy Flaud - French Group: 0% Maryanne Smith - Langley: +3% UV: -5% Microwave: Pure Rotation Lines

6. Remote Sensing of Water Vapor at the ARM Sites Sonde Issues (Spatial, Temporal, Accuracy (Bias)) Column: Microwave Atmospheric Measurement (mwr scaled sondes) Transition Frequencies Strengths (Stark Effect: 0.5%) Widths (Temperature Dependence) Shape: Voigt Continuum Tropospheric Profile: Raman Lidar Night/Day Cloud Clearing

7. Spectral Brightness Temperature and MWR Frequencies

8. MWRP / MonoRTM Residuals (5 frequencies) HalfWidth: MONORTM Value PWV: Retrieved from 23.835 GHz BT_MWRP a + b * BT_MWRP

9. MWR - Modeled (PWV scaled to match 23.8 GHZ MWR)

10. Atmospheric Validation of Forward Model 1.Measurement Instrument Function - Photometry AERI - HIS AIRS sfc air space 2.Characterization of the Atmospheric Path including Surface Sonde - Temperature - Water Vapor 3.Forward Model Line Parameters LBLRTM (line shape) Continuum Atmospheric Spectroscopy from Space: long paths, cold temperatures

11. (AIRSobs-AIRScalc)- (SHISobs-SHIScalc) (K) “AIRS SHIS Comparison 2” (21 November 2002) Excluding channels strongly affected by atmosphere above ER2 Revercomb et al.

12. Remote Sensing of Temperature in the Infrared Carbon Dioxide Transition Frequencies (Pressure Shift) Strengths Widths (Temperature Dependence) Shape: Voigt Chi Function (function and temperature dependence) Galatry …. (transition from Doppler to Voigt) Line Coupling (Perturbation Approach/Exact Diagonalization) Q Branches P and R Branches Continuum

13. Chi function: The spectral function by which the Lorentz line shape (impact) must be multiplied to obtain the “true” line shape. Continuum: Includes following contributions 25 cm -1 beyond line center within -/+ 25 cm -1 at 25 cm-1 value

14. AERI Downwelling at the Surface Arctic SHIS AFWEX Upwelling at 8 km Dry

15. AIRS 1200 resolving power LBLRTM HITRAN 2000 LBLRTM (Gaussian) CO 2 ( 2) O 3 CH 4 H 2 O (1.63 prec. cm pwv) CO 2 ( 3) HITRAN 2000 AIRS Validation with Sonde/Climatological Profile Troposphere Stratosphere H2OH2O

16. Residuals vs Brightness Temperature  2 band 3 band Stratosphere Troposphere

17. Climatology Sonde Temperature Retrieval using the 3 CO2 Band

18. AIRS Validation with Retrieved Temperature Profile AIRS 1200 resolving power LBLRTM HITRAN 2000 LBLRTM (Gaussian) CO 2 ( 2) O 3 CH 4 H 2 O (1.63 prec. cm pwv) CO 2 ( 3) H2OH2O

19. AIRS Validation with Retrieved Temperature Profile ( 3) AIRS 1200 resolving power LBLRTM HITRAN 2000 LBLRTM (Gaussian) CO 2 ( 2) O 3 CH 4 H 2 O (1.63 prec. cm pwv) CO 2 ( 3) H2OH2O AIRS 1200 resolving power LBLRTM HITRAN 2000 LBLRTM (Gaussian) CO 2 ( 2) O 3 CH 4 H 2 O (1.63 prec. cm pwv) CO 2 ( 3) HITRAN 2000 AIRS Validation with Sonde/Climatological Profile

20. 2

21. Remote Sensing of Water Vapor in the Infrared Atmospheric Measurement (mwr scaled sondes) Transition Frequencies (Pressure Shifts) Strengths Widths (Temperature Dependence) Shape: Voigt Continuum Definition: Continuum is that absorption with slow spectral dependence which, when added to the line by line absorption, provides agreement with measurement. Scaling: Dependence on pressure, temperature and mixing ratio must be ‘robust’ mt_ckd:Contributions from two sources: Allowed line contribution Collision-Induced contribution

22. Radiance (mW / m^2 sr cm-1) Wavenumber (cm-1) AERI_ER Validation in the Polar Window ARM NSA Retrieved Column Water Vapor HITRAN 2000/2004 mt_ckd_1.1 N 2 O Q Branch CO 2 Q Branch

23. _ 1% Toth AERI Downwelling at the Surface ARM SGP Moist

24. CAMEX HIS Upwelling at 20 km Ocean - low pwv Temp: R ( 2) CO2 Water Vapor: Retrieved Temp: R ( 2) CO2 Water Vapor: Sonde Temp: Retrieved Water Vapor: Retrieved

25. HIS CO Region: Upwelling at 20 km Ocean low pwv __ __ __ __ __ H 2 O CO 2 Q

26. Summary Water Vapor Effectively no ground truth Reasonable consistency across the band NO evidence (yet) for -line shape other than Voigt -higher spectral content for the continuum Significant improvement in line parameters since IRS 2004 (MIPAS-EOS) BUT Spectroscopy is the current limitation on the accuracy of retrievals from space! Carbon Dioxide 2 and 3 are not consistent ( 2 strengths are effectively ~4%.gt. 3) Water vapor temperature retrieval consistent with 3 Issues chi factor Continuum Line coupling: Q and P & R http://rtweb.aer.com