Detailed measurements of snow accumulation throughout the year have been conducted remotely at two Automatic Weather Station (AWS) sites on the Ross Ice Shelf, Antarctica, and an Automatic Geophysical Observatory (AGO) located on the Antarctic polar plateau. Measurements were made between November 1995 and November 1996 at Ferrell AWS (78.02 degrees S, 170.80 degrees E; elevation 45 m), between December 1996 and November 1997 at Marilyn AWS (79.98 degrees S, 165.03 degrees E; elevation 75 m) and between November 1995 and November 1997 at AGO-2 (85.67 degrees S, 46.38 degrees W; elevation 1860 m). High temporal resolution snow accumulation characterizations were conducted at each site using an acoustic snow depth gauge (SR50, Campbell Scientific, Inc.) and a Microsphere Dispersal System (MDS) which automatically disperses of inert, colored glass microspheres onto the snow surface at 14 day intervals to provide snow horizon dating (Braaten and Ratzlaff, 1998). The acoustic snow depth gauge measured snow surface height with a time resolution of 30 minutes (AGO) to 60 minutes (AWS), with an accuracy of plus or minus 10 millimeters. The dated, colored glass microsphere horizons allowed the mass accumulation for specific periods to be determined. Meteorological data including wind speed and direction, temperature, and pressure were also measured at intervals of 1 minute (AGO) to 10 minutes (AWS). Spatial variability of annual snow accumulation at each site was determined by manual measurements of a snow stake array obtained during each site visit.
From SR50, MDS and snow pit stratigraphy data, snow accumulation at all sites was clearly found to be an episodic process. The Ross Ice Shelf sites where found to have the largest number of snow accumulation events. Since the timing of the snow accumulation events are known with good precision, meso-scale, synoptic scale, and planetary scale meteorological features associated with each event have been examined using satellite imagery and output from operational models. The satellite imagery consists of 3-hourly infrared composite images from geostationary and polar orbiting satellites provided by the Space Science and Engineering Center, University of Wisconsin - Madison. The operational model output used are the model initialization (zero hour forecast) surface pressure fields from the Medium Range Forecast (MRF) Model produced by the National Centers for Environmental Prediction