A Statistical Correlation Method for the Retrieval of Atmospheric Moisture Profiles by Microwave Radiometry

Ramesh K. Kakar Earth and Space Sciences Division, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109

Search for other papers by Ramesh K. Kakar in
Current site
Google Scholar
PubMed
Close
and
Bjorn H. Lambrigtsen Instit te for Atmospheric Optics and Remote Sensing, Hampton, VA 23666

Search for other papers by Bjorn H. Lambrigtsen in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

A statistical correlation technique is applied to the retrieval of vertical moisture profiles under clear-skyconditions from down-looking radiometric measurements of atmospheric radiation at microwave wavelengths. For a given set of channels, the method selects the optimum radiometric channels for estimating water vapor at specific pressure levels between the surface and 300 mb. The water vapor mixing ratio at these pressure levels is then calculated from a linear combination of the selected channel brightness temperatures. To test its validity the algorithm was applied, in a numerical experiment, to fifty independent tropical radiosondes.The rms absolute deviation of the estimated moisture profiles from the actual profiles was comparable to that obtained using an iterative retrieval method reported earlier. The statistical method, however, requires several orders of magnitude less computer time than the iterative method; it is suitable for high speed processing of large amounts of data.

Abstract

A statistical correlation technique is applied to the retrieval of vertical moisture profiles under clear-skyconditions from down-looking radiometric measurements of atmospheric radiation at microwave wavelengths. For a given set of channels, the method selects the optimum radiometric channels for estimating water vapor at specific pressure levels between the surface and 300 mb. The water vapor mixing ratio at these pressure levels is then calculated from a linear combination of the selected channel brightness temperatures. To test its validity the algorithm was applied, in a numerical experiment, to fifty independent tropical radiosondes.The rms absolute deviation of the estimated moisture profiles from the actual profiles was comparable to that obtained using an iterative retrieval method reported earlier. The statistical method, however, requires several orders of magnitude less computer time than the iterative method; it is suitable for high speed processing of large amounts of data.

Save