Session: Glacial Climates (LGM, Last deglaciation, Ice sheet uncertainties, Glacial-interglacial cycles)
Author: A. Quiquet / Aurelien.Quiquet@lsce.ipsl.fr / LSCE, France
Co-author: D. Roche, LSCE; Earth and Climate Cluster, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, the Netherlands;
C. Dumas, LSCE, France;
The disintegration of the Northern Hemisphere ice sheets during the deglaciation, starting from ~ 21 kaBP, resulted in large and global modifications of the Earth climate. Multiple feedbacks are associated with the ice sheets (albedo, topography, runoff) and their importance remains debated. To further advance on this topic, we use the climate model of intermediate complexity iLOVECLIM v1.1. This coupled climate system includes atmospheric, ocean and vegetation components dynamically coupled. In its latest version, it most notably also includes an interactive ice sheet model, coupled to the atmosphere thanks to an online and conservative dynamical downscaling procedure for heat and moisture. Freshwater fluxes due to ice sheet melt and calving are transferred to the ocean in a consistent and conservative way, hence allowing for a complete closure of the water cycle. In the proposed paper, we will analyze results from multiple 21 ky long integrations of the model with both interactive and prescribed ice sheets. The importance of the corresponding ice sheet geometries and freshwater fluxes on the global climate can thus be readily evaluated together with the associated feedbacks. The simulations with prescribed ice-sheets follow the PMIP4 protocol using both provided transient reconstructions. This work is hence a contribution to the PMIP4 last glacial maximum and last deglaciation working groups.