Changing trends in Arctic sea ice volume

Arctic sea ice has undergone massive changes in the latest decades. Not only has the ice extent seen a great reduction over the satellite era, sea ice thickness is also strongly altered as a result of changing climate conditions. In this study, we look at sea ice volume in the Arctic and show how its response to increasing temperatures has changed in recent years. Using a Bayesian statistical framework, we look at reanalysis data of sea ice volume and detect changepoints in trends. We have identified an abrupt change in Arctic sea ice volume relative to global mean temperature. Spatial analysis shows that this signal of abrupt change primarily stems from loss of sea ice thickness in the Canadian Basin and Beaufort Gyre region. We compare these findings with CMIP6 Earth system models and find similar behaviour in several models. Further, we have conducted experiments with the NorESM model to better describe the mechanisms of this abrupt change, and to see how the sea ice volume behaves if global warming is later reversed.