Session Details

What did the ice sheets do, why, and how did they affect the rest of the climate system, especially via freshwater fluxes? This session, sponsored by MOCA (Meltwater routing and Ocean-Cryosphere-Atmosphere response) is intended to further develop interdisciplinary links between the glaciological, Quaternary terrestrial, paleoceanographic, and ice sheet modeling communities that are required to address these questions. Comparing the deglaciation chronologies of the major Weichselian ice sheets and discussing the differences in reconstructions and methods will be part of the main theme of this session. These topics also need to be addressed in the context of the increasing resolution and physical complexity of ice sheet models, which raise the demands for detailed paleo-datasets for input, constraint, and comparison of the results.

Current modelling challenges include ice shelves, ice streams, and calving - features that are crucial for understanding rapid disintegration of major ice sheets, and therefore important to understand in a warming world. How do associated changes in freshwater discharge affect the rest of he climate system, especially in the context of abrupt changes that are linked to rapid shifts in the meridional overturning circulation? Further open questions of interest for this session include: How is the coupling between ice and climate affected by the geography and time dependence of the freshwater discharge? Can past climate oscillations be reproduced given inferred discharge and associated uncertainties? What is the range of response between different GCM's and what are the specific reasons for the differences? What was the role of sea ice in mediating the impact of freshwater forcing on climate? And what old and new observational evidence can be used to further constrain the models and our collective understanding?