Arctic: New "Spurensucher" for climate research

"Multi Scat" is investigating meltwater tempels and thin sea ice

Read out

Melting-water tempels and thin sea-ice are among the many largely unexplored phenomena in the Arctic. Because with the unique radar device "Multi Scat", scientists now want to get to the bottom of these phenomena on the ground. The findings of the measurement campaign will significantly improve sea ice prediction using existing and future satellites.

{1l}

The team of scientists headed by Stefan Kern from the Institute of Oceanography at the University of Hamburg will leave on 28 July 2007 aboard the research vessel "Polarstern" for an Arctic expedition, in which the Multi³Scat will be used on board a helicopter together with a video and thermal imaging camera becomes. Urgently required comparative data on satellite observations of thin sea ice and melting ponds are to be obtained - with the aim of being able to better interpret these observations.

Melting pools are formed every summer on the Arctic sea ice and accelerate the melting process by absorbing solar energy. In addition, they pretend satellite sensors open water, where in fact is still sea ice. Field measurements show that such ponds can often cover up to 40 percent of sea ice. Where, when and in which area the smelting pools cover the sea ice in summer is as unclear today as the mapping and thickness measurement of thin sea ice in winter.

Thin sea ice in sight of the researchers

Thin sea ice, that is frozen seawater with a thickness of up to 30 centimeters, often occurs in the gutters between thick ice floes. In these channels, the ocean releases a lot of heat to the atmosphere. At the same time the ice grows very fast here. The effects of gutters and melting ponds are currently insufficiently reproduced by existing computer models for sea ice prediction. Reliable observations of gutter and melt pond distribution would close a major gap in the quality assurance of such computer models. display

The measurements with Multi³Scat are complemented by on-site measurements of snow and ice parameters, for example ice thickness, which are carried out in cooperation with scientists from the Alfred Wegener Institute for Polar and Marine Research Bremerhaven.

By analyzing this unique dataset, the Hamburg team aims to optimize methods for monitoring the distribution and thickness of thin sea ice and, for the future, to determine the sea ice surface covered with melting ponds. These findings will be incorporated into the development of new ESA satellites. The Multi³Scat was developed with the support of the University of Hamburg.

(idw - University of Hamburg, 25.07.2007 - DLO)