Surface Mass Balance Model CISSEMBEL linking ice sheets and ESMs: Results of standalone GrSMBMIP simulations

When you want to know the future of the Greenland ice sheet, you are confronted with the question: What will be Greenland's surface mass balance (SMB) in the future? 

The Copenhagen Ice-Snow Surface Energy and Mass Balance Model (CISSEMBEL) is a unified surface mass balance model developed at the Danish Meteorological Institute (DMI) that serves dual purposes in climate modeling. First, it operates as a standalone model to compute surface mass balance (SMB) from a wide range of atmospheric forcing data, including reanalysis products, meteorological forecasts, and automatic weather station (AWS) observations. Second, it acts as an innovative coupling framework that integrates SMB modeling into an atmospheric model. Since CISSEMBEL corrects dynamically elevation differences between the coarsely resolved orography in global atmosphere models and the high-resolution target during runtime, CISSEMBEL delivers boundary conditions essential for accurate atmosphere-ice sheet interactions. Ultimately, it enables a seamless integration of Ice Sheet Models (ISMs) into Earth System Models (ESMs).

In this presentation, we show CISSEMBEL results following the protocol of the Greenland Ice Sheet (GrIS) SMB model intercomparison project (GrSMBMIP). We present results on the grid of the used EraInterim (EraI) forcing as well as higher-resolution simulations on an Ice Sheet Model Intercomparison (ISMIP) grid. Our model results show that initialization affects the final results. Also, the different downscaling approaches (directly to a higher-resolution target or via height classes) available in CISSEMBEL deliver similar results. Since various parameterizations are available, the user can analyze their impact on results and explore the consequences on the SMB that determines Greenland’s future.