Elevation classes as a surface mass balance downscaling method for coupling of ice sheet and climate models

Coupling of ice sheet and climate models is an active area of research due to the potential ice sheets have to modify the climate. In order to couple an ice sheet model to a climate model, the climate model has to provide a surface mass balance (SMB) forcing to the climate model. Here we present a method, elevation classes, as a possible method to downscale the SMB simulation. The elevation classes method calculates energy and mass components in the land model, at several fixed elevations using an imposed lapse rate of -6K/km for temperature. Through bilinear (horizontal) and linear (vertical) interpolation, the SMB calculated at 10 elevations is downscaled from the climate model grid ( 100km) to the ice sheet model grid (5km).Here we evaluate the downscaled energy and mass fluxes calculated by the elevation classes over Greenland in the Community Earth System Model, by comparing with regional climate models and observations. Furthermore, an assessment of the impact on the Arctic climate (circulation, sea ice) by including elevation classes in the climate model is shown and finally we will address the sensitivity of the modelled SMB to choice in lapse rate for downscaling.