Coupling the freshwater feedback into EC-Earth using the ice sheet model BISICLES

Recent observations show that the Antarctic ice sheet is losing mass at an accelerating pace and that this is projected to accelerate in the coming decades, contributing significantly to sea level rise. Ice sheet contributions to sea level rise remains one of the largest sources of uncertainty to fu...

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Bibliographic Details
Main Authors: Donnelly, C., van der Linden, E., Jüling, A., Drijfhout, S., Payne, A.
Format: Conference Object
Language:English
Published: 2023
Subjects:
Online Access:https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021812
Description
Summary:Recent observations show that the Antarctic ice sheet is losing mass at an accelerating pace and that this is projected to accelerate in the coming decades, contributing significantly to sea level rise. Ice sheet contributions to sea level rise remains one of the largest sources of uncertainty to future projections. However, so far ice sheets are not included in the majority of climate models used in CMIP5/CMIP6 to make sea level projections. Therefore, to accurately simulate future climate and sea level rise, ice sheet models need to be included in Earth System Models. Here, ocean temperatures from EC-Earth with CMIP6 forcing are used to calculate basal melt forcing for BISICLES. Ocean temperatures are averaged over five oceanic sectors of Antarctica and three different depth ranges. Then, a quadratic basal melt parameterisation calibrated on sea level contribution derived from observation-based changes in grounding line ice discharge is applied as forcing for BISICLES. Based on this methodology, freshwater feedback was then coupled asynchronously into EC-Earth at one-year intervals. We find that the choice of calibration and ocean temperature depth range significantly impacts the basal melt calculation and additionally show initial results from the freshwater feedback coupling.