Mesoscale Vortices in the Weddell Sea Region (Antarctica)

Abstract

Preliminary results of investigations of Antarctic mesocyclones in the Weddell Sea region are presented for the Antarctic summer periods 1983?88. Based on NOAA and METEOR satellite images, a total of 195 mesoscale vortices (scale less than 1000 km) were observed and classified using a simple classification scheme, depending on lifetime and cortex diameter. The highest frequency of vortices was found over the ice free part of the eastern Weddell Sea. Mean synoptic conditions for vortices with scales less than 400 km near Halley Station indicate an offshore flow being most favorable for their development. A case study with satellite images, surface measurements, synoptic analyses derived from TOVS data shows the evolution of several mesoscale vortices in a pool of cold air in the eastern Weddell Sea.