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Strong wind events in the Antarctic

Turner, John; Chenoli, Sheeba Nettukandy; abu Samah, Azizan; Marshall, Gareth; Phillips, Tony; Orr, Andrew. 2009 Strong wind events in the Antarctic. Journal of Geophysical Research, 114 (D8), D18103. 25, pp. 10.1029/2008JD011642

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Abstract/Summary

We use quality controlled in situ meteorological observations collected at Antarctic research stations over the last 60 years to carry out the first continent-wide investigation into the occurrence, variability, and trend in strong wind events (SWEs). Reanalysis/analysis fields are used to examine the synoptic background in which such events take place. SWEs are a feature of the extended winter season and involve a complex interaction between the downslope buoyancy forcing and the pressure gradient force from synoptic-scale cyclones. Around the coast of East Antarctica the significant majority of SWEs are associated with enhancement of the downslope katabatic flow by the broadscale synoptic circulation, involving a deepening of pressure off the coast and an increase of pressure inland. Orientation of the valleys in relation to the cyclone track is critical in enabling enhancement of the katabatic winds. Casey, Mawson, and Dumont d'Urville stations report the greatest number of winds of storm force and stronger. Interannual variability of SWE numbers is large. Trends in the number of winter strong wind reports are small. The greatest statistically significant increase in wind speed since the 1950s has been at Faraday/Vernadsky and Syowa stations. The largest wind speed increases since 1979 have been at Davis and Mawson stations. Comparison with high-resolution numerical simulations showed that the reanalysis/analysis fields are able to capture the large-scale synoptic features and the associated enhancement of the katabatic flow but underestimated the observed wind speed if it was strongly influenced by local topographical conditions.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1029/2008JD011642
Programmes: BAS Programmes > Polar Science for Planet Earth (2009 - ) > Climate
ISSN: 0148-0227
NORA Subject Terms: Meteorology and Climatology
Date made live: 15 Nov 2010 12:09
URI: http://nora.nerc.ac.uk/id/eprint/11330

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