Monitoring the Distribution of Cirrus Clouds from the Afternoon A-Train

摘要

Cirrus cloud microphysical and radiative properties are poorly understood. This research aims to gain a better characterization of both the microphysical properties and the distribution of cirrus. A multiple- channel cirrus cloud retrieval combining passive and active measurements was developed with consideration of the instrumentation available on the NASA Afternoon A-Train constellation of satellites. An optimal estimation- based algorithm employing a version of the split- window technique was implemented to retrieve cirrus properties; the inclusion of explicit cloud boundary information available from space-borne lidar or radar was shown to significantly reduce retrieval error. The flexibility of the optimal estimation framework, however, also allows for ease of incorporation of visible and near-IR wavelengths into the retrieval to increase total information. Sensitive studies and an information content analysis were performed for the MODIS channels to determine which combination of wavelengths would be most desirable for the full retrieval.