Sea ice at the edge: Seasonal Arctic sea ice in coupled climate models and satellite observations

Abstract:

Changes at the margins of Arctic sea ice cover have profound consequences for ecosystems, regional climate and ocean circulation. The heterogeneous and dynamic nature of seasonal sea ice is difficult to capture, both in coupled climate models and in observations. Hence, there are numerous definitions of the marginal ice zone used by modelers and observers, muddying how scientists communicate about changes at the sea ice edge. Here, we present an evaluation of simulated characteristics in seasonal Arctic sea ice in the latest generation of coupled global climate models, CMIP6, using satellite observations. This analysis includes regional metrics and consideration of seasonality and variability. We quantify the impact of winds on sea ice at the edge of the pack using coupled model simulations where winds are nudged towards observations. We also consider the impact of ocean surface waves on sea ice using new climate model simulations incorporating coupled wave-ice interactions. Finally, we discuss how these results motivate new observational work to improve simulation of past and future change in the Arctic.