Adding a dynamical cryosphere into i LOVECLIM (version 1.0) – Part 1: Coupling with the GRISLI ice-sheet model

Abstract. We present the coupling approach and the first results of the GRISLI ice-sheet model within the iLOVECLIM coupled climate model. The climate component is a relatively low resolution Earth System Model of Intermediate complexity, well suited for long-term integrations and thus for coupled climate–cryosphere studies. We describe the coupling procedure with emphasise on the downscaling scheme and the methods to compute the snow fraction from total precipitation fields. We then present results for the Northern Hemisphere ice sheet (Greenland) under pre-industrial climate conditions at the end of a 14 000 yr-long integration. The obtained simulated ice sheet presents a too large thickness in central Greenland owing to the overestimation of precipitation in the atmospheric component. We find that including downscaling procedures for temperature improves the temperature distributions over Greenland for both summer and annual mean temperatures. Overall, we find an ice-sheet areal extent in reasonnable agreement with the observed Greenland ice sheet given the simplicity of the chosen climate model.