Some Aspects of High Latitude Southern Hemisphere Summer Circulation as Viewed by ESSA 3

Abstract

The computer-generated digital mosaics of daily cloud photographs obtained by the ESSA 3 satellite were studied for the Southern Hemisphere south of 40S for the period of the southern summer, December 1966 to February 1967. The distribution and movement of the large-scale vortex patterns enabled a number of regions of high frequency of cyclones, cyclogenesis and cyclolysis to be located over the ocean areas surrounding Antarctica and the principal trajectories of cyclones over the southern oceans to be examined. These results are in substantial agreement with earlier synoptic studies. Little evidence was found for frequent cyclogenesis at latitudes close to the Antarctic coast and mid-latitude cyclogenesis was frequently observed without classical frontal wave cloud sequences. The areas of high cyclonic frequency and of cycloysis close to the Antarctic coast for the period of the study are found to be consistent with some known features of mean annual precipitation over the continent. Particular regions of frequent low cloudiness were observed close to the coast of Antarctica.