Cooperative Institute for Research in Environmental Sciences

Identification of Surface Wind Patterns over the Ross Ice Shelf, Antarctica Using Self Organizing Maps

Melissa A Nigro and John J. Cassano

2014, Monthly Weather Review, 142, 2361-2378, doi: 10.1175/MWR-D-13-00382.1

The interaction of synoptic and mesoscale circulations with the steep topography surrounding the Ross Ice Shelf, Antarctica greatly influences the wind patterns in the region of the Ross Ice Shelf. The topography provides forcing for features such as katabatic winds, barrier winds and barrier wind corner jets. The combination of topographic forcing and synoptic and mesoscale forcing from cyclones that traverse the study area create a region of strong, but varying winds. This paper identifies the dominant surface wind patterns over the Ross Ice Shelf using output from the Weather Research and Forecasting model run within the Antarctic Mesoscale Prediction System. The dataset has 15 km grid spacing and is the first study to identify the dominant surface wind patterns using data at this resolution. The analysis shows the Ross Ice Shelf airstream, a dominant stream of air flowing northward from the interior of the continent over the western and/or central Ross Ice Shelf to the Ross Sea, is present over the Ross Ice Shelf approximately 34% of the time. An analysis that identifies the dominant Ross Ice Shelf airstream patterns is also presented. This analysis indicates that the Ross Ice Shelf airstream varies in both its strength and position over the Ross Ice Shelf.