The Extreme Wind Events in the Ross Island Region of Antarctica Journal Article uri icon

Overview

abstract

  • Abstract; Numerous incidents of structural damage at the U.S. Antarctic Program’s (USAP) McMurdo Station due to extreme wind events (EWEs) have been reported over the past decade. Utilizing nearly 20 yr (~1992–2013) of University of Wisconsin automatic weather station (AWS) data from three different stations in the Ross Island region (Pegasus North, Pegasus South, and Willie Field), statistical analysis shows no significant trends in EWE frequency, intensity, or duration. EWEs more frequently occur during the transition seasons. To assess the dynamical environment of these EWEs, Antarctic Mesoscale Prediction System (AMPS) forecast back trajectories are computed and analyzed in conjunction with several other AMPS fields for the strongest events at McMurdo Station. The synoptic analysis reveals that McMurdo Station EWEs are nearly always associated with strong southerly flow due to an approaching Ross Sea cyclone and an upper-level trough around Cape Adare. A Ross Ice Shelf air stream (RAS) environment is created with enhanced barrier winds along the Transantarctic Mountains, downslope winds in the lee of the glaciers and local topography, and a tip jet effect around Ross Island. The position and intensity of these Ross Sea cyclones are most influenced by the occurrence of a central Pacific ENSO event, which causes the upper-level trough to move westward. An approaching surface cyclone would then be in position to trigger an event, depending on how the wind direction and speed impinges on the complex topography around McMurdo Station.

publication date

  • June 1, 2016

Date in CU Experts

  • December 15, 2016 4:49 AM

Full Author List

  • Weber NJ; Lazzara MA; Keller LM; Cassano JJ

author count

  • 4

Other Profiles

International Standard Serial Number (ISSN)

  • 0882-8156

Electronic International Standard Serial Number (EISSN)

  • 1520-0434

Additional Document Info

start page

  • 985

end page

  • 1000

volume

  • 31

issue

  • 3