A parametric study of sea level and grounding line projections in the Amundsen Sea sector for coupled solid Earth - ice sheet models.

Abstract

The evolution of the Antarctic Ice Sheet (AIS) represents one of the most important and uncertain contributions to sea level rise in the upcoming centuries. Thwaites glacier and the Amundsen Sea sector of the West Antarctic Ice Sheet (WAIS) have been identified as the continent's most critical areas. The retreat of Thwaites' glacier grounding line - the transition area where ice is no longer grounded and becomes afloat - is the subject of considerable study for modelers as it governs the collapse of the glacier.   Recent advances towards coupling of dynamical ice models with Glacial Isostatic Adjustment (GIA) models has provided the means to improve grounding line projections by considering solid-Earth processes and their interactions with the cryosphere and hydrosphere. However, the spatial and temporal model resolution necessary to fully capture these interactions, and its sensitivity to model parametrization, remains elusive.   We investigate the grounding line retreat of Thwaites Glacier through 2350 using the parallelized coupled physics capabilities of the Ice-sheet and Sea-level System Model (ISSM) which capture the complex interactions between solid-Earth, ice-sheets, and ocean. We incorporate realistic climatology, ocean melt rates, and GIA models and we discuss the impact of spatial and temporal model resolution, and solid-Earth parametrization, on the grounding line retreat and sea level change.   © 2024 California Institute of Technology. Government sponsorship acknowledged.