An Investigation of Synoptic and Associated Mesoscale Patterns Leading to Significant Weather Days at McMurdo Station, Antarctica.

Defense Meteorological Satellite Program DMSP and National Oceanic and Atmospheric Administration satellite imagery are used to supplement conventional radiosonde and aircraft data in an investigation of synoptic and associated mesoscale weather patterns leading to significant weather at McMurdo Station and the adjacent Ross Ice Shelf. Three case studies, 8-11 January 1976, 22-25 December 1975, and 11-13 October 1973, are analyzed, with concentration on the 700 and 400 mb levels. Meridional advection associated with ridging over the Ross Ice Shelf andor the polar plateau serves as the moisture intrusion mechanism for significant weather in each case study. Mesoscale features about the McMurdo area serve as both triggering and blocking mechanisms preceding the significant weather events. Katabatic winds associated with glacial valley warming, originating from the polar plateau near McMurdo, are detected on DMSP infrared satellite imagery. Comparisons between Fleet Numerical Weather Centrals 700 mb analyses with those of the author demonstrate the inadequacy of satellite-void analyses over the sparse data icesnow covered south polar region.