For most of us, Antarctic sea ice is an abstraction – something far away we may have seen on a documentary. But the radiant white sheets of ice floating on the seas around the snowy continent are a crucial component of Earth’s climate processes.
Sea ice insulates the ocean, reflects heat, drives currents, supports ecosystems and protects ice shelves. It also has an annual seasonal cycle – some of the ice melts, then freezes again.
Every year, the cycle of freeze and melt around Antarctica has been extremely reliable. Until recently.
