New research describes for the first time the role that
warm, dry winds (katabatic winds) play in influencing the behaviour of Antarctic ice shelves. Presenting this week at a European conference scientists from British Antarctic Survey (BAS) explain how
spring and summer winds, known as föhn winds, are prevalent on the Larsen C Ice Shelf, West Antarctica and creating melt pools. The Larsen C Ice Shelf is of particular interest to scientists because it of the collapse of Larsen A in 1995 and Larsen B in 2002.
The researchers observed the föhn winds, which
blow around 65% of the spring and summer period, extend further south and are more frequent than previously thought, and are likely to be a contributing factor that weakens ice shelves before a collapse. The results are presented this week (Tuesday 25 April) at the European Geosciences Union General Assembly (EGU) in Vienna.
In 1995 and 2002, the Larsen A and B ice shelves collapsed, depositing an area the size of Shropshire into the Weddell Sea. Whilst ice shelf collapse doesn't directly contribute to sea level rise, the glaciers which fed into the ice shelves accelerated, leading to the loss of land ice, and subsequently indirect sea level rise. The processes responsible for the collapse of these ice shelves were largely debated, and
it is now thought that crevasses on the ice shelf were widened and deepened by water draining into the cracks. Föhn winds are thought to be responsible for melting the ice shelf surface and supplying the water.
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