Coupling the polar ice sheets to the Norwegian Earth System Model: advances and challenges

The polar ice sheets are melting faster due to climate change, with the contribution of the Greenland and Antarctic ice sheets being the largest uncertainty in projecting future sea level rise. Understanding this is crucial for assessing impacts on the environment and ecosystems. Most of the existing modelling studies focus on ice sheet response to atmospheric and oceanic forcing. However, the ice sheets closely interact with and influence the Earth’s climate. With the goal of better representing ice sheet and climate processes and feedbacks, we aim to integrate Greenland and Antarctic dynamic ice sheet components into the Norwegian Earth System Model (NorESM). NorESM is a global, CMIP-type coupled model for the physical climate system and biogeochemical processes over land, ocean, sea ice and atmosphere. In its latest release, NorESM features interactive coupling with a dynamic Greenland Ice Sheet (GrIS) component, although this coupling does not explicitly include ocean forcing at the marine-terminating margins of the ice sheet. In this presentation, we will show preliminary results of NorESM simulations featuring (1) a new interactive coupling with the Community Ice Sheet Model (CISM) over both the Antarctic and Greenland domains, and (2) a new ocean and ice sheet coupling allowing us to force the ice sheets with horizontally and vertically resolved  NorESM ocean properties. We will discuss work in progress, highlighting recent advances and most pressing challenges of our coupling approach.