Detection and Retrieval of Cirrus Cloud Systems Using AVHRR Data: VerificationBased on FIRE-II-IFO Composite Measurements

摘要

A numerical scheme has been developed to identify multilayer cirrus cloud systemsusing AVHRR data based on the physical properties of the AVHRR channels 2-1 reflectance ratios, the brightness temperature differences between Chs. 4 and 5, and the Ch. 4 brightness temperatures. Subsequently, we have devised an algorithm for the retrieval of cirrus cloud optical depths and ice crystal sizes in multilayer cloud systems based on the theory of radiative transfer and parameterizations. Both the detection and retrieval results have been validated from the cloud conditions, optical depths, and mean effective ice crystal sizes inferred from the collocated and coincident ground-based lidar and radar images, balloon-borne replicator data, aircraft 2D probe data, and NCAR CLASS temperature and humidity sounding data on a case-by-case basis.