Precipitation pathways for five new ice core sites in Ellsworth Land, West Antarctica
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Ice cores provide a wealth of information about past climate and atmospheric circulation however a good understanding of the precipitation patterns, potential source regions and transport pathways is essential in their interpretation. Here we investigate the precipitation pathways for a transect of five new ice cores drilled in the southern Antarctic Peninsula and Ellsworth Land. We utilize in situ observations from automatic weather stations to confirm that the European Centre for Medium-Range Weather Forecasts ERA-Interim reanalysis data adequately captures annual and sub-annual variability, with evidence of a slight cold bias in the 2 m temperatures. Back trajectory analysis, from the British Atmospheric Data Centre trajectory service, reveals that warm and snowy years are associated with air masses that originate (5 days before reaching the site) from the Amundsen-Bellingshausen Sea, while cold and dry years are associated with air masses from the Antarctic continent. There is a clear seasonal migration in the trajectories at each site, reflecting the east to west migration of the Amundsen Sea Low, known to have a strong influence on climate in this region.
KeywordsAntarctica Climate variability Ice cores Precipitation Back trajectories
This work was funded by the British Antarctic Survey core programme and part funded by the Natural Environment Research Council (Grant NE/J020710/1). We would like to thank ECMWF for the reanalysis data, BADC for their trajectory service, the Rothera Met team (S. Colwell and others) for deploying the AWS and D. Bromwich and an anonymous reviewer for their valued suggestions.
- Abram NJ, Thomas ER, McConnell JR, Mulvaney R et al (2010) Ice core evidence for a 20th century decline of sea ice in the Bellingshausen Sea, Antarctica. J Geophys Res 115 Google Scholar
- Lenaerts JTM, van den Broeke MR, van de Berg WJ et al (2012) A new, high-resolution surface mass balance map of Antarctica (1979–2010) based on regional atmospheric climate modeling. J Geophys Res 39:L04501Google Scholar
- Medley B, Joughin I, Das SB, Steig EJ, Conway H et al (2013) Airborne-radar and ice-core observations of annual snow accumulation over Thwaites Glacier, West Antarctica confirm the spatiotemporal variability of global and regional atmospheric models. Geophys Res Lett 40(14):3649–3654CrossRefGoogle Scholar
- Nicolas J, Bromwich DH (2011) Precipitation changes in high Southern latitudes from global reanalyses: a Cautionary Tale. S. Geophysics 32:475–494Google Scholar
- Thomas ER, Bracegirdle TJ, Turner J, Wolff EW (2013) A 308 year record of climate variability in West Antarctica. Geophys Res Lett 40:GL057782Google Scholar