The layer between ice and snow is thin – only a few millimetres thick. To investigate it, a team led by snow researcher, Martin Schneebeli, is spending the coming winter on the icebreaker, ‘Polarstern’, of the Alfred Wegener Institute. In the autumn, the ship will let itself become attached to the ice as part of an expedition north of Norway. There it will drift for a year through the Arctic Ocean, passing close to the North Pole, before being released North-East of Greenland in the summer of 2020. Martin will investigate the thermal conductivity of sea ice covered with snow. It describes how well the sea and the air are insulated from each other, which is important for estimating how the glaciation of the Arctic Ocean is changing under climate change.
Today we know that snow-covered ice insulates much better than could theoretically be expected. Researchers have found a possible explanation in the cold laboratory in Davos. “In the experiment, a very thin layer was formed, consisting almost entirely of air, between the ice and snow. It massively reduced the heat flow,” explains Martin. During the MOSAiC expedition, he will now regularly collect snow-ice samples and analyse them with a computer tomograph. The reason why the scientist will be on the expedition is that he is keen to see whether he will also find this thin layer in a natural environment. (Birgit Ottmer, Diagonal 1/19)