Expedition to measure the polar meltdown

by Stuart Corner

Tuesday, 16 October 2007

Page 2 of 3 Hadow will use a 4kg impulse radar (reduced from 100kg) which has taken his team two years to develop, backed up by a daily programme of manual ice-coring to determine snow and ice-thickness. The survey will provide over 10 million readings and will for the first time gather separate measurements of the thickness of the ice and overlying snow, including the little-studied region of the central Arctic. Hadow is working in collaboration with oceanographers and climatologists at the University of Cambridge and the US Naval Postgraduate School. NASA, the UK Met Office and the European Space Agency are also linked to the project. The data secured by Hadow's polar survey team will be used to reassess existing satellite and submarine-generated data and to provide a firmer date for the ice cap's loss. "Remote-sensing instruments aboard submarines, aircraft and satellites cannot measure separately the thickness of the ice and snow layers. This complicates the processing of the data and requires adjustments involving poorly-known densities of sea ice and snow. So this data becomes estimations rather more than actual measurements," said Hadow. "There is no substitute for taking the measurements directly from the surface of the cap. Such a surveying service can only be done by the few who are accustomed to the rigours and hazards of travelling on the sea ice," he said. No satellites are able to obtain image or other data from the top two degrees latitude of the earth's surface. At present, satellite photography of the North Geographic Pole assumes the ice cap is there and colours it in white. Satellite determinations have, at present, some associated errors, in spite of the billions spent on them. Dr Joao Rodrigues, the survey's head of science, and a member of the Polar Oceans Physics Group at the University of Cambridge, added: "Up to now, most estimates for the likely disappearance of the permanent ice cap have been based on the current rate of shrinking, coupled with complex climatic models. However, reliable predictions are hampered by the fact that the actual thickness distribution of the Arctic ice cover is not accurately known. << First page <   1 2 3 Next page > Last page - Post your comment >>

 

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