An electromagnetic “bird” dispatched to the Arctic for the most detailed look yet at the thickness of the ice has turned up a reassuring picture.
The meltdown has not been as dire as some would suggest, said geophysicist Christian Haas of the University of Alberta. His international team flew across the top of the planet last year for the 2,412-kilometre survey.
They found large expanses of ice four to five metres thick, despite the record retreat in 2007.
“This is a nice demonstration that there is still hope for the ice,” said Haas.
The survey, which demonstrated that the “bird” probe tethered to a plane can measure ice thickness over large areas, uncovered plenty of resilient “old” ice from Norway to the North Pole to Alaska in April 2009.
There is already speculation about how the ice will fare this summer, with some scientists predicting a record melt. Haas said he doesn’t buy it.
He said the ice is in some ways in better shape going into the melt season than it has been for a couple of years. “We have more thick ice going into the summer than we did in 2009 and 2008,” he said.
Much will depend on the intensity of the winds, and how the ice fractures and is blown around, he said. “But any talk about tipping points, a sudden drop and no recovery . . . I don’t think it is going to happen.”
The more likely scenario is that the ice will continue a decline that has been underway for at least 30 years, he said. There is likely to be plenty of variability in that decline, he added, with “extreme” melts in some years, followed by “significant recoveries like we saw last year.”
Part of the problem with ice forecasting is that it based largely on data from satellites. They are good at measuring how large an area is covered by ice, but tell little about its thickness — which can measure in mere centimetres in the case of new ice, or metres in the case of ice several years old.
The thickness had “changed little since 2007, and remained within the expected range of natural variability,” the team reports in the Geophysical Research Letters.