Published online in Wiley Online Library (wileyonlinelibrary.com) DOI:10.1002/joc.3481 Regional climate variability driven by foehn winds in the McMurdo Dry Valleys, Antarctica

ABSTRACT: Warm, dry and gusty foehn winds are frequently experienced in the McMurdo Dry Valleys (MDVs), Antarctica; however, their significance in the region’s climate is unknown. Foehn events in the MDVs are caused by topographic modification of southwesterly airflow which is related to the occurre...

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Bibliographic Details
Main Authors: Int J. Climatol, Johanna C. Speirs, A Hamish A. Mcgowan, A Daniel F. Steinhoffb, David H. Bromwichb
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Subjects:
Royal Meteorological Society
Antarctic
McMurdo Dry Valleys
Ross Sea
The Antarctic
Antarc*
Antarctica
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.668.7604
http://polarmet.osu.edu/PMG_publications/speirs_mcgowan_ijoc_2012.pdf
Description
Summary:ABSTRACT: Warm, dry and gusty foehn winds are frequently experienced in the McMurdo Dry Valleys (MDVs), Antarctica; however, their significance in the region’s climate is unknown. Foehn events in the MDVs are caused by topographic modification of southwesterly airflow which is related to the occurrence of synoptic-scale cyclones in the Amundsen/Ross Sea region. The intra- and interannual frequency and intensity of foehn events therefore varies in response to the position and frequency of cyclones in this region that are believed to be strongly influenced by the El Niño Southern Oscillation (ENSO) and the Southern Annular Mode (SAM). Here, we present a 20-year climatology of foehn winds from observational records in the MDVs. The SAM is found to significantly influence foehn wind frequency during the Antarctic summer and autumn months, whereas ENSO only holds significant correlations with winter air temperatures in the MDVs. The positive relationship between the SAM and the foehn wind regime in summer is particularly significant as foehn winds frequently cause summer temperatures to rise above 0 °C leading to extensive melt and thaw in MDVs. Foehn winds are a major climatological feature of the MDVs with their frequency and duration affecting the region’s temperature records and their trends. Accordingly, analysis of the region’s weather and climate records and predictions of future impacts of climate change on the MDVs is incomplete without consideration of foehn winds and their influence. Copyright 2012

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