Interpretation of Satellite Cloud Mosaics for Southern Hemisphere Analysis and Reference Level Specification

Abstract

A semi-objective procedure has been developed to modify mean sea level pressure and 1000?500 mb thickness using cloud vortex patterns obtained from satellite imagery. The method combines the previous work of Nagle and Hayden (1971) and Troup and Streten (1972), and is designed for operational use, particularly in the Southern Hemisphere. The method is capable of reproducing synoptic-scale structure which can be deduced from cloud data, but which is often difficult to incorporate in a numerical analysis system using ?bogus? observations. Two case studies are used to illustrate its application: the first demonstrates the ability of the procedure to correct large-scale ?first guess? errors, and the second compares results of a forecast/analysis cycle using this method with operational products of the National Meteorological Analysis Centre of the Australian Bureau of Meteorology.