Changes to the Canadian Arctic Archipelago Sea Ice and Freshwater Fluxes in the Twenty-First Century under the Intergovernmental Panel on Climate Change A1B Climate Scenario

Abstract

A coupled ocean and sea-ice pan-Arctic model forced by the Intergovernmental Panel on Climate Change A1B climate scenario is used to study the evolution of ice and ocean surface conditions within the Canadian Arctic Archipelago (CAA) during the twenty-first century. A summer ice-free CAA is likely by the end of our simulation. Sea ice undergoes significant changes from the mid-2020s to the mid-2060s in both concentration and thickness. The simulation shows a shrinking of 65% and a thinning of 75% in summer over the 40 years, resulting in a partially open Northwest Passage by the 2050s. However, ice in central Parry Channel might increase due to a decrease in export from April to June, linked to a reduced cross-channel sea surface height (SSH) gradient, before melting thermodynamically. On a larger scale, the central CAA throughflow will experience a significant decrease in both volume and freshwater transport after 2020, which is related to the change in the SSH difference between the two ends of Parry Channel, particularly the lifting of SSH in Baffin Bay. With a lower albedo, a warmer ocean is simulated, particularly in summer. The sea surface salinity within the CAA demonstrates a strong decadal oscillation without a clear trend over the entire simulation. A north–south pattern, separated by Parry Channel, is also found in the changes of ocean temperature and salinity fields due to different ice conditions.