Synoptic weather types for the ross sea region, Antarctica

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TitleSynoptic weather types for the ross sea region, AntarcticaAbstractSynoptic classifications over the Southern Ocean in the Ross Sea region of Antarctica (508S-Antarctic coast, 1508E-908W) have been derived from NCEP reanalysis data (1979-2011), producing a set of six synoptic types for the region. These types describe realistic synoptic conditions for the region and represent the moisture-bearing low pressure systems that circulate around Antarctica. The types are described as follows: lowBellingshausen/Amundsen (L-BA), low (L), zonal (Z), lowRoss (L-R), ridge (R), and lowAmundsen (L-A). Seasonal frequencies of the synoptic types reflect the seasonal zonal shift of the Amundsen Sea low (ASL) and also correlate well with the Southern Oscillation index (SOI) and the southern annular mode (SAM). Variability in the occurrences of the synoptic types L-R and L-BA indicate a shifting of the position of the ASL farther east (west) toward (away from) the Antarctic Peninsula during La NinÂ a (El NinÂ o) and positive (negative) SAM conditions. A joint linear regression of the SOI and SAM indices show the strongest correlations with thetypes L-BA and L-R in the spring and quantifies the joint forcing effect of these climate cycles on synoptic variabilityin the region. As a demonstration of how synoptic classification provides links between large-scale atmospheric circulation and local climate parameters, the synoptic types are related to precipitation and temperature at Roosevelt Island, an ice core site on the Ross Ice Shelf (808S, 1608W). The synoptic types provide quantification of distinct precipitationand temperature regimes at this site, which allows for more fundamental understanding of the precipitation source regions and transport pathways that drive the variability in snow and ice proxies. ï¿½ 2013 American Meteorological Society.AcknowledgementsThe authors greatly appreciate the support of the University of Wisconsin---Madison Automatic Weather Station Program and Antarctic Meteorological Research Center for the AWS datasets and Matthew Lazzara in particular for information provided on the Antarctic AWS datasets. We also appreciate use of NCEP reanalysis data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado. Two of the authors (SD and JR) were part funded through core funding from the New Zealand Ministry of Science and Innovation.

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TypeArticleCitationCohen, L., Dea, S. and Renwick, J. (2013). Synoptic weather types for the ross sea region, Antarctica. Journal of Climate, 26(2): 636-649 IdentifierCohen2013bRelevancerank1