BBC: The Catlin Arctic Survey team is using a novel mobile radar dragged behind one of its sledge to record the thickness of the sea ice. The data will be used to calibrate satellite observations of the Arctic ice, and to constrain the computer models that are used to forecast its likely response to climate change. The endeavour came very close to a premature end last week when re-supply flights were grounded and the team got down to its last 12,000 calories of rations. Pen …