Wednesday, 12 January 2005
Investigating Antarctic Precipitation in the Ross Island Region From Various Observing Platforms
Determining the precipitation distribution across Antarctica presents challenges not found in the mid-latitudes. A lack of sufficient numbers of in situ measurements and the ambiguities resulting from blowing snow prevent continent scale mapping of precipitation by traditional methodologies. Alternatively, precipitation estimation using remote sensing by satellite has been suggested, but the complexities of estimating snowfall over snow-covered Antarctica using microwave data present new difficulties that are also unique to the polar environment. This study uses a variety of methods, including surface measurements, satellite data, and model simulations to examine falling precipitation in Antarctica. Acoustic depth gauges, instrumented on University of Wisconsin Automatic Weather Stations (AWS), provide ground measurements on and near the Ross Ice Shelf. A combination of polar orbiting satellite data from Aqua and the NOAA series, including infrared and microwave channels, determine the presence of storm systems. Further examination of cyclones over the Ross Ice Shelf are conducted with the University of Wisconsin Non-hydrostatic Modeling System (UW-NMS), a cloud resolving model, with simulations over Antarctica run on differing precipitating cloud systems. The UW-NMS model simulations will not only verify the existence of storm systems but will supplement the lack of surface measurements. A case study examining the combination of these observing platforms and modeling can be used simultaneously to estimate precipitation over the Ross Ice Shelf and Ross Island areas.