Articles | Volume 13, issue 11
Clim. Past, 13, 1491–1513, 2017

Special issue: Climate of the past 2000 years: regional and trans-regional...

Clim. Past, 13, 1491–1513, 2017

Research article 10 Nov 2017

Research article | 10 Nov 2017

Regional Antarctic snow accumulation over the past 1000 years

Elizabeth R. Thomas1, J. Melchior van Wessem2, Jason Roberts3,4, Elisabeth Isaksson5, Elisabeth Schlosser6,7, Tyler J. Fudge8, Paul Vallelonga9, Brooke Medley10, Jan Lenaerts2, Nancy Bertler11,12, Michiel R. van den Broeke2, Daniel A. Dixon13, Massimo Frezzotti14, Barbara Stenni15,16, Mark Curran3, and Alexey A. Ekaykin17,18 Elizabeth R. Thomas et al.
  • 1Ice Dynamics and Paleoclimate, British Antarctic Survey, Cambridge, UK CB3 0ET
  • 2Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, Utrecht, the Netherlands
  • 3Antarctic Climate and Ecosystems, Australian Antarctic Division, Hobart, Tasmania 7050, Australia
  • 4Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, 7001, Australia
  • 5Geology and Geophysics, Norwegian Polar Institute, 9296 Tromsø, Norway
  • 6Institute of Atmospheric and Cryospheric Sciences, Austrian Polar Research Institute, Vienna, Austria
  • 7Institute of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria
  • 8Earth and Space Sciences, University of Washington, Seattle, USA
  • 9Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
  • 10Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
  • 11Antarctic Research Centre, Victoria University, Wellington 6012, New Zealand
  • 12National Ice Core Research Laboratory, GNS Science, Lower Hutt 5040, New Zealand
  • 13Climate Change Institute, University of Maine, Orono, Maine 04469, USA
  • 14ENEA, Agenzia Nazionale per le nuove tecnologie, l'energia e lo sviluppo sostenibile, Rome, Italy
  • 15Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Venice, Italy
  • 16Institute for the Dynamics of Environmental Processes, CNR, Venice, Italy
  • 17Climate and Environmental Research Laboratory, Arctic and Antarctic Research Institute, St. Petersburg, 199397, Russia
  • 18Institute of Earth Sciences, Saint Petersburg State University, St. Petersburg, 199178, Russia

Abstract. Here we present Antarctic snow accumulation variability at the regional scale over the past 1000 years. A total of 79 ice core snow accumulation records were gathered and assigned to seven geographical regions, separating the high-accumulation coastal zones below 2000 m of elevation from the dry central Antarctic Plateau. The regional composites of annual snow accumulation were evaluated against modelled surface mass balance (SMB) from RACMO2.3p2 and precipitation from ERA-Interim reanalysis. With the exception of the Weddell Sea coast, the low-elevation composites capture the regional precipitation and SMB variability as defined by the models. The central Antarctic sites lack coherency and either do not represent regional precipitation or indicate the model inability to capture relevant precipitation processes in the cold, dry central plateau. Our results show that SMB for the total Antarctic Ice Sheet (including ice shelves) has increased at a rate of 7 ± 0.13 Gt decade−1 since 1800 AD, representing a net reduction in sea level of ∼ 0.02 mm decade−1 since 1800 and ∼ 0.04 mm decade−1 since 1900 AD. The largest contribution is from the Antarctic Peninsula (∼ 75 %) where the annual average SMB during the most recent decade (2001–2010) is 123 ± 44 Gt yr−1 higher than the annual average during the first decade of the 19th century. Only four ice core records cover the full 1000 years, and they suggest a decrease in snow accumulation during this period. However, our study emphasizes the importance of low-elevation coastal zones, which have been under-represented in previous investigations of temporal snow accumulation.

Short summary
Regional Antarctic snow accumulation derived from 79 ice core records is evaluated as part of the PAGES Antarctica 2k working group. Our results show that surface mass balance for the total Antarctic ice sheet has increased at a rate of 7 ± 0.13 Gt dec-1 since 1800 AD, representing a net reduction in sea level of ~ 0.02 mm dec-1 since 1800 and ~ 0.04 mm dec-1 since 1900 AD. The largest contribution is from the Antarctic Peninsula.