Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 16, 4757-4770, 2016
https://doi.org/10.5194/acp-16-4757-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
18 Apr 2016
Precipitation and synoptic regime in two extreme years 2009 and 2010 at Dome C, Antarctica – implications for ice core interpretation
Elisabeth Schlosser1,2, Barbara Stenni3, Mauro Valt4, Anselmo Cagnati4, Jordan G. Powers5, Kevin W. Manning5, Marilyn Raphael6, and Michael G. Duda5 1Inst. of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria
2Austrian Polar Research Institute, Vienna, Austria
3Department of Environmental Sciences, Informatics and Statistics, University of Venice, Venice, Italy
4ARPA Center of Avalanches, Agenzia Regionale per la Prevenzione e Protenzione Ambientale de Veneto, Italy
5National Center for Atmospheric Research, Boulder, CO, USA
6Department of Geography, University of California, Los Angeles, California, USA
Abstract. At the East Antarctic deep ice core drilling site Dome C, daily precipitation measurements were initiated in 2006 and are being continued until today. The amounts and stable isotope ratios of the precipitation samples as well as crystal types are determined. Within the measuring period, the two years 2009 and 2010 showed striking contrasting temperature and precipitation anomalies, particularly in the winter seasons. The reasons for these anomalies are analysed using data from the mesoscale atmospheric model WRF (Weather Research and Forecasting Model) run under the Antarctic Mesoscale Prediction System (AMPS). 2009 was relatively warm and moist due to frequent warm air intrusions connected to amplification of Rossby waves in the circumpolar westerlies, whereas the winter of 2010 was extremely dry and cold. It is shown that while in 2010 a strong zonal atmospheric flow was dominant, in 2009 an enhanced meridional flow prevailed, which increased the meridional transport of heat and moisture onto the East Antarctic plateau and led to a number of high-precipitation/warming events at Dome C. This was also evident in a positive (negative) SAM (Southern Annular Mode) index and a negative (positive) ZW3 (zonal wave number three) index during the winter months of 2010 (2009). Changes in the frequency or seasonality of such event-type precipitation can lead to a strong bias in the air temperature derived from stable water isotopes in ice cores.

Citation: Schlosser, E., Stenni, B., Valt, M., Cagnati, A., Powers, J. G., Manning, K. W., Raphael, M., and Duda, M. G.: Precipitation and synoptic regime in two extreme years 2009 and 2010 at Dome C, Antarctica – implications for ice core interpretation, Atmos. Chem. Phys., 16, 4757-4770, https://doi.org/10.5194/acp-16-4757-2016, 2016.
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Short summary
Striking differences in the atmospheric flow and thus weather conditions in 2009 and 2010 at the Antarctic deep ice core drilling site Dome C were investigated using a mesoscale atmospheric model and precipitation measurements, and implications for interpretation of ice cores are discussed. Stable isotope ratios are commonly used to derive paleotemperatures and are strongly influenced by the prevailing atmospheric flow regime, namely a strong zonal flow or a highly meriodional flow.
Striking differences in the atmospheric flow and thus weather conditions in 2009 and 2010 at the...
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