《《Snow accumulation》.pdf

Available online at Polar Science 5 (2011) 327e336 /polar/ Snow accumulation, melt, mass loss, and the near-surface ice temperature structure of Irenebreen, Svalbard I. Sobota Department of Cryology and Polar Research, Institute of Geography, Nicolaus Copernicus University, Gagarina 9, 87-100 Torun, Poland Received 27 March 2010; revised 22 May 2011; accepted 23 June 2011 Available online 2 July 2011 Abstract This study examines the mass balance, accumulation, melt, and near-surface ice thermal structure of Irenebreen, a 4.1 km2 glacier located in northwest Spitsbergen, Svalbard. Traditional glaciological mass balance measurements by stake readings and snow surveying have been conducted annually at the glacier since 2002, yielding a mean annual net mass balance of 65 cm w.e. for the period 2002e2009. In 2009, the annual mass balance of Irenebreen was 63 cm w.e. despite above-average snow accu- mulation in winter. The near-surface ice temperature in the accumulation area was investigated with automatic borehole therm- istors. The mean annual surface ice temperatures (SeptembereAugust) of the accumulation area were 3.7 C at 1 m depth and 3.3 C at 10 m depth. Irenebreen is potentially polythermal, with cold ice and a temperate surface layer during summer. This temperate surface layer is influenced by seasonal changes in temperature. In winter, the temperature of all the ice is below the melting point and temperate layers are probably p