Satellite check: Polar aircraft from the AWI begins an expedition to the Arctic

Within the framework of the expedition ‘CryoVex 2004’ the aircraft ‘Polar 4’, operated by the Foundation Alfred Wegener Institute for Polar and Marine Research (AWI), is on a 3 week Arctic trip to conduct ice surveys. The measurements are to be used in preparation for a mission by the European space satellite ‘CryoSat’ which will survey the polar ice caps and sea ice beginning November 2004. The satellite is to determine whether ice recedes or increases in response to global climate change.

‘CryoVex 2004’ is an international program co-ordinated by the European Space Agency (ESA). Participants are German, Norwegian, British, Canadian and Danish researchers. They will conduct measurements above inland ice caps of Austfonna (Spitsbergen), Devon Island (Canadian Arctic) and central Greenland. Some of the research groups will conduct field measurements to characterise the snow layer and surface features on site. The objective of the aerial surveys at 1150 meters altitude is to provide simultaneous measurements at equivalent locations to ground level recordings, in order to quantify the signal properties and penetration of radar into the inland ice under specific snow conditions. For this purpose, the surface topography of the inland ice will be measured simultaneously with radar- and laser altimeters. The radar altimeter ASIRAS (Airborne Synthetic Aperture Radar Altimeter System), specifically developed for ‘Polar 4’, was built exactly in accordance with the concept of the altimeter on board ‘CryoSat’. Thus, the flight measurements allow for a reliable interpretation of equivalent new ‘CryoSat’ data. This is the only possible approach for analysing satellite data.

An earlier program on Spitsbergen at the beginning of April 2004 proved the functionality of the complete diverse array of measuring instruments under polar conditions. A preliminary analysis of the resulting data showed good correspondence between laser and radar measurements. Because of its logistic equipment and extensive experience in the performance and analysis of the field measurements, the Foundation Alfred Wegener Institute for Polar and Marine Research is a leading partner in the ‘CryoSat’ team of ESA. Furthermore, it accommodates a project office for the preparation of the ‘CryoSat’ mission in Germany. The program will run through May 7 2004. ‘Polar 4’ will return to Bremerhaven on May 8 2004.

Bremerhaven, April 22 2004