Research News
Polar 6 with shiny turbo propellers, picture taken at Novo station. Photo: Johannes Käßbohrer, Fielax, Bremerhaven
Polar 6 on First Mission to Antarctic
The new polar research aircraft Polar 6 has successfully returned from its first research mission to the Antarctic. The aircraft of the Basler BT-67 type is equipped with numerous specially developed devices for capturing geophysical data and for exact surveying of the several kilometre thick ice crust. The Federal Ministry of Research funded the purchase and equipping of Polar 6 at the Alfred Wegener Institute for Polar and Marine Research with a total of 9.78 million Euro.
The AWI experts have equipped the research aircraft Polar 6 with special instruments. Openings in the top and bottom of the aircraft allow for the fixture of various sensors. In addition to a configuration for geophysical measurements, the aircraft thus can be equipped also especially for measurements in the atmosphere, to name an example. "With the Polar 6 we can respond to the huge demand for research flights to the polar regions", explains Prof. Dr Heinrich Miller, Deputy Director at the AWI. It is now possible, he adds, to carry out important investigations in the Arctic in spring without having to shorten the Antarctic season at the same time.
The first mission of Polar 6 was predominantly in the service of the "CryoSat-2 Validation Experiment" conducted in the Eastern Antarctic by AWI scientists together with colleagues from the Australian University of Tasmania. They are supported by the Australian Antarctic Division (AAD) and the European Space Agency (ESA). "We surveyed the Totten Glacier and the Law Dome to acquire data that will enable us to check the accuracy of ESA’s CryoSat-2 satellite”, says Dr Veit Helm, geophysicist at the AWI.
The CryoSat-2 satellite has been orbiting around the Earth since April 2010. It records changes in sea ice thickness and changing surface heights of land ice in the Arctic and Antarctic and in this way supplies important data for climate research. Over Antarctica, for instance, its two radar antennas measure to an accuracy of a few centimetres how high glaciers rise up from the surface. This data allows to check whether and to which extent the inland ice masses of the Antarctic increase or shrink.
The CryoSat-2 validation experiment examines the influence exerted by physical properties of the top snow and ice layer on the radar signal that the satellite emits and receives. "Depending on such factors as the particle size of the snow, the extent to which it has compacted and how it is layered, the radar signal can penetrate deeper or less deep and is thus reflected differently. If we ignore these factors in the data evaluation, it may result in misinterpretations”, explains Veit Helm.
The measurements of the new research aircraft Polar 6 form a link between the satellite measurements from space and corroborative investigations on the ground conducted by the Australian team. The scientists on the ground drove across the selected investigation areas in snowmobiles and dug snow pits into the uppermost layer of snow and ice to directly examine its physical properties.
