Spatial and temporal variability of snow accumulation rate on the East Antarctic ice divide between Dome Fuji and EPICA DML

Shuji Fujita ,Fumio Nakazawa ,Margareta Hansson ,Susanne Ingvander ,Torbjörn Karlin ,Yoshiyuki Fujii ,Johan Ström ,Hideaki Motoyama ,Teruo Furukawa ,Satoru Imura ,Yoshinori Iizuka ,Hans Oerter ,Ivar Andersson ,Per Holmlund ,Kotaro Fukui ,Lars E Sjöberg ,Keiichiro Hara ,Shin Sugiyama ,Ian A Brown ,Hiroyuki Enomoto ,Sylviane Surdyk ,Ho‐Shing Yu ,Koji Fujita ,Makoto Igarashi ,Ryu Uemura ,Frank Wilhelms

doi:10.5194/tc-5-1057-2011

Abstract

Abstract. To better understand the spatio-temporal variability of the glaciological environment in Dronning Maud Land (DML), East Antarctica, a 2800-km-long Japanese-Swedish traverse was carried out. The route includes ice divides between two ice-coring sites at Dome Fuji and EPICA DML. We determined the surface mass balance (SMB) averaged over various time scales in the late Holocene based on studies of snow pits and firn cores, in addition to radar data. We find that the large-scale distribution of the SMB depends on the surface elevation and continentality, and that the SMB differs between the windward and leeward sides of ice divides for strong-wind events. We suggest that the SMB is highly influenced by interactions between the large-scale surface topography of ice divides and the wind field of strong-wind events that are often associated with high-precipitation events. Local variations in the SMB are governed by the local surface topography, which is influenced by the bedrock topography. In the eastern part of DML, the accumulation rate in the second half of the 20th century is found to be higher by ~15 % than averages over longer periods of 722 a or 7.9 ka before AD 2008. A similar increasing trend has been reported for many inland plateau sites in Antarctica with the exception of several sites on the leeward side of the ice divides.

Highlights

1.1 Surface mass balance of AntarcticaSea-level rise has been a debated issue in recent climatological studies related to global warming (Lemke et al, 2007)
Several features can be identified in the data: (i) generally, the Dome Fuji area exhibits low values; (ii) along the main ice divide route, the annual accumulation rate values are smoother and larger than for the south route; (iii) there are large fluctuations of up to ∼20 % along the south route and along the Dome Fuji route close to MD550; (iv) values are generally lower along the south route than along the main ice divide route
In the JASE traverse, we investigated spatial and temporal variability of the ice sheet environment in the sparsely explored inland plateau area of East Antarctica

Summary

Introduction

1.1 Surface mass balance of AntarcticaSea-level rise has been a debated issue in recent climatological studies related to global warming (Lemke et al, 2007). Assessing the mass balance and surface mass balance (SMB) of the Antarctic ice sheet has been a major concern of recent studies (Arthern et al, 2006; Chen et al, 2006; Davis et al, 2005; Giovinetto and Zwally, 2000; Helsen et al, 2008; Van de Berg et al, 2006; Velicogna and Wahr, 2006). Several approaches for constraining the mass balance of the Antarctic ice sheet are based on the interpolation of accumulation rates obtained from field data such as firn cores, snow pits or stake readings, sometimes using background. A number of preliminary results have already been presented, in addition to those described in the present paper An example of such efforts is the Norwegian-USA traverse (IPY) through East Antarctica. The traverse has provided new data sets for the SMB based on ground-based accumulation measurements through large parts of DML to the South Pole (Anschutz et al, 2009, 2011; Muller et al, 2010)

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