Validation of AIRS CO Retrievals for Air Quality and Transport Assessments
Abstract
Proper validation of remote sensing observations is crucial to employ them in quantitative measurements of air quality, transport, and model evaluations. In particular, high quality satellite remote sensing measurements of boundary layer composition are necessary for assessing air quality where we live near the surface. We present the latest validation results for retrievals of tropospheric carbon monoxide (CO) from spectra acquired by the Atmospheric InfraRed Sounder (AIRS) onboard NASA's Aqua satellite including a preliminary assessment of AIRS CO retrieval accuracy in the boundary layer. In situ aircraft measurements obtained during the INtercontinental chemical Transport EXperiment-North America (INTEX-A) during the summer of 2004 and INTEX- B (Phase B) during the spring of 2006 provide the necessary profile measurements for validation of AIRS mid- tropospheric CO retrievals. The in situ CO measurements from the DACOM instrument flying onboard NASA's DC-8 are convolved with the AIRS CO averaging kernels and the convolved profiles are then compared to the AIRS retrievals. This convolution process accounts for the amount of the first guess CO profile remaining in the AIRS retrieval and simulates the vertical smoothing applied by the AIRS CO retrieval algorithm. The bias is less than 10% and the RMS error in mid-tropospheric AIRS CO retrievals is less than the 15% level predicted from pre-launch simulations. Retrievals of boundary layer CO from ground-based up-looking remote sensing observations at the DOE ARM CART site near Lamont, Oklahoma provide the assessment of AIRS CO retrievals in the boundary layer. Additional comparisons of total column CO retrievals to ground-based spectroscopic measurements will be presented. These comparisons show good agreement in some geographic locations for some conditions, but also point out particular issues to be addressed in version 6 of the AIRS CO retrieval algorithm.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2008
- Bibcode:
- 2008AGUSM.A33A..12M
- Keywords:
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- 0322 Constituent sources and sinks;
- 0345 Pollution: urban and regional (0305;
- 0478;
- 4251);
- 0365 Troposphere: composition and chemistry;
- 0368 Troposphere: constituent transport and chemistry;
- 3360 Remote sensing