An analysis of dramatic decreases in atmospheric pressure across the Ross Ice Shelf through automatic weather station (AWS) observations and archived numerical weather prediction output

The Ross Ice Shelf region has received much attention through the placement of automatic weather stations (AWS) across the region since the 1980s. Within these AWS observations are occurrences of dramatic decreases in atmospheric pressure (approximately 40 mb) over periods of less than 48 hours. This presentation will show the results of a climatological study on the frequency and characteristics of the occurrences of dramatic decreases in atmospheric pressure across the Ross Ice Shelf. Supporting atmospheric features will be studied through the use of the archived output from Antarctic Mesoscale Prediction System (AMPS). The influence of mesocyclones, katabatic winds, and the larger Ross Ice Shelf air stream (RAS) will evaluated to determine the role of these features on the dramatic decreases in atmospheric pressure. The results will highlight the role and occurrences of these events in the larger meteorological picture of the Ross Ice Shelf region.