Microwave Brightness Temperature and Its Relation to Atmospheric General Circulation Features.

摘要

Microwave Sounding Unit (MSU) global brightness temperature fields are compared with observed atmospheric general circulation features for the purpose of determining the extent to which MSU brightness temperature relates to observed atmospheric circulation. A six-week MSU data set covering 8 Jan 87 - 18 Feb 87 is analyzed. Global and hemispheric projections of MSU Channel 2 (53.74 GHz), Channel 3 (54.96 GHz), and Channel 4 (57.95 GHz) brightness temperature fields are presented in two divisions; 8-31 Jan and 1-18 Feb 87. Complementary data sets of temperature, zonal wind, geopotential height, and streamfunction are developed using model analyses from the European Centre for Medium Range Weather Forecasts (ECMWF) and the National Meteorological Center (NMC) for the purpose of a comparative study. MSU thermal fields may be considered an estimate of atmospheric mean-layer temperature through levels determined by each channel's weighting function. (EMK)