Sensitivity of Future Projections of the Wilkes Subglacial Basin Ice Sheet to Grounding Line Melt Parameterizations

• DOI: 10.5194/egusphere-2024-1005
• Publication Date: 2024-04-22T11:28:40Z
• Authors: Yu Wang; Chen Zhao; Rupert Gladstone; Thomas Zwinger; Ben Galton-Fenzi; Poul Christoffersen
• Keywords: Antarctic ice sheet; Line (geometry)

Abstract. Projections of Antarctic Ice Sheet mass loss and therefore global sea level rise are hugely uncertain, partly due to how the ice sheet occurs at grounding line. The Wilkes Subglacial Basin (WSB), a vast region East sheet, is thought be particularly vulnerable deglaciation under future climate warming scenarios. However, projections loss, driven by line migration, known sensitive parameterisation ocean-induced basal melt floating shelves, specifically, adjacent – termed Grounding Line Melt Parameterizations (GLMPs). This study investigates dynamics in WSB with respect four GLMPs both upper lower bounds scenarios from present 2500, different model resolutions choices sliding relationships. variation these determines distribution amount applied finite element assembly procedure on partially grounded elements (i.e., containing line). Our findings indicate that significantly affect trigger-timings tipping points overall magnitude loss. We conclude applying full melting elements, which causes side line, should avoided all circumstances its poor numerical convergence substantial overestimation recommend preferring options depend specific context, either 1) not any immediately or 2) employing sub-element parameterisation. Based our best results, point projected occur between 2200 2300, leading massive rapid retreat across significant increase discharge 200 500 Gt a-1. In this simulations suggest could contribute 0.23 0.34 m 2500.