Influence of surface mass balance on the high-end sea-level commitment from the Antarctic Ice Sheet

Over the last decades, the Antarctic Ice Sheet (AIS) has been losing mass, mainly through icedischarge and sub-shelf melting (Rignot et al. 2019). More specifically, recent observations showthat the AIS is currently losing mass at an accelerating rate in areas subject to strong ocean induced melt. A...

Full description

Bibliographic Details
Main Authors: Coulon, Violaine, Ann Kristin, Klose, Kittel, Christoph, Winkelmann, Ricarda, Pattyn, Frank
Other Authors: EGU General Assembly 2022 (23-27 May 2022: Vienna, Austria & Online)
Format: Conference Object
Language:English
Published: 2022
Subjects:
Online Access:http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/353961
https://dipot.ulb.ac.be/dspace/bitstream/2013/353961/3/EGU22-5983-print.pdf
Description
Summary:Over the last decades, the Antarctic Ice Sheet (AIS) has been losing mass, mainly through icedischarge and sub-shelf melting (Rignot et al. 2019). More specifically, recent observations showthat the AIS is currently losing mass at an accelerating rate in areas subject to strong ocean induced melt. At the same time, no long-term trend in snowfall accumulation changes can bedetected in the interior of the ice sheet. Due to these current trends, basal melting has often beenconsidered as the main driver of future Antarctic mass loss. However, even though stronger basalmelting of ice shelves is projected to drive future AIS mass loss, recent studies (e.g. Seroussi et al.2020) have shown that surface mass balance (SMB, the balance of accumulation through snowfalland ablation through erosion, sublimation and runoff) has a strong potential in controlling thefuture stability and evolution of the Antarctic Ice Sheet. With increasing temperatures, SMB isexpected to increase in Antarctica in the future as a result of enhanced snowfall. As long as thewarming remains modest, other AIS SMB components (such as runoff) will likely continue to play aminor role in future SMB changes (Lenaerts et al. 2019; Kittel et al. 2021). Under high-emissionscenarios, however, future runoff is likely to significantly compensate for mass gain throughsnowfall (Kittel et al 2021). The balance between these competing processes is still a matter ofdebate and, as of yet, there is no consensus on estimates of the future mass balance of theAntarctic Ice Sheet (Seroussi et al. 2020).Here, we investigate the relative importance of SMB changes and ocean-induced melt on the long-term (multi-centennial to multi-millennial) AIS response as well as their associated uncertainties.To do so, we force two ice sheet models (fETISh and PISM) with atmospheric and oceanicprojections inferred from a subset of models from the sixth phase of the Coupled ModelIntercomparison Project (CMIP6) under the Shared Socioeconomic Pathways (SSP) 5-8.5 andSSP1-2.6. Changes in ...