Arctic sea ice - where are we headed?

Abstract

Over the last 45 years Arctic sea ice extent has almost halved, particularly in summer. However, the underlying processes are still insufficiently understood, hampering our ability to attribute causes and to predict consequences. At the core of the uncertainties are the complexities of the sea ice energy and momentum balance that govern variations in sea ice mass balance. I will present examples from various recent field campaigns that address different components of the energy and momentum balance. Among those are airborne observations of ice thickness redistribution, variability, and change in the Northwest Passage and Last Ice Area, as well as ship-based observations of sea ice melt in the Marginal Ice Zone. At last, I will address some open questions related to the recent rapid decline of Antarctic sea ice, particularly the roles of ocean and atmosphere forcing quite different to the Arctic, and the interaction of sea ice with ice shelf melt.