Record-breaking winter winds have blown old Arctic sea ice into the melt zone

An unusual pattern of winds drove old Arctic sea ice into a precarious position in the winter of 2020. Now in warming waters, large swathes of the Arctic’s diminishing store of old ice lie at risk of melting. But how did this happen, and why is old ice so important?

When winter’s darkness falls on the Arctic Ocean, temperatures plunge to below -30°C. Existing floating ice thickens as the seawater below freezes, and the ice advances into areas that were previously open water. In summer, when temperatures rise and the sun shines for months at a time, the ice thins and retreats. Each September,…

© La Conversation - vendredi 6 août 2021