Atmospheric Infrared Sounder (AIRS) Retrieval of Atmospheric Carbon Dioxide (CO2) in Three Layers
E.T. Olsen1, M. Chahine1, T.S. Pagano1, L.L. Chen1, X. Jiang2 and Y.L. Yung3
1Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109; 818-354-7604, E-mail: Edward.T.Olsen@jpl.nasa.gov
2University of Houston, Houston, TX 77204
3California Institute of Technology, Pasadena, CA 91125
The AIRS mid-tropospheric global CO2 data product spanning September 2002 to the present may be freely downloaded from the Goddard Earth Sciences/Data and Information Services Center. Access links to the products are provided on the web page http://airs.jpl.nasa.gov/AIRS_CO2_Data.
We present a monthly global climatology of the mid-tropospheric CO2 for 60°S ≤ LAT ≤ 90°N. The AIRS mid-tropospheric data product is now being used by several groups in modeling efforts to understand the sources and sinks and the lifting of CO2 from surface layers into the free troposphere.
We have retrieved Stratospheric CO2 at 30 km altitude, and global maps show significant interaction between the stratosphere and troposphere beyond the tropical pipe. The latitudinal variation of CO2 agrees well with the sparse in situ measurements but not with model results.
We are evaluating preliminary retrievals of lower-tropospheric CO2, between the surface and 2.2 km (775 hPa) and will show global maps of early results.
Figure 1. Left panel shows January 2003 monthly average of AIRS retrieved stratospheric CO2 and right panel shows 3-D IMATCH stratospheric CO2. The model CO2 profile has been convolved with the AIRS weighting function for this match. The tropical pipe is evident in both panels. The AIRS data show additional tropospheric intrusion at the high northern latitudes and a variation with latitude that is approximately a factor of four greater than in the model.