When it comes to maintaining sea ice in the Arctic, it seems, there are good cyclones and there are bad ones. Last year brought the bad kind. In early August 2012, an unusually large and intense storm barrelled into the Arctic from Siberia. The cyclone churned for nearly two weeks at the height of the summer melt season, contributing to the break-up of the ice, which was already thin and weak, owing to a warm, early start to the season. By September, Arctic sea ice had shrunk to a record low of just 3.4 million square kilometres. Yet this year, the summer storms that have passed over the Arctic have fulfilled their usual role, bringing snow and cooler air to slow the melting. At present, with the summer thaw set to end in just a few weeks, sea-ice cover stands at around 5.7 million square kilometres (see 'Slippery slope').
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