par Raspoet, Olivia 
;Coulon, Violaine ;Pattyn, Frank
Référence EGU General Assembly 2026 (3-8 May 2026: Vienna, Austria)
Publication Non publié, 2026-05-05
;Coulon, Violaine ;Pattyn, Frank Référence EGU General Assembly 2026 (3-8 May 2026: Vienna, Austria)
Publication Non publié, 2026-05-05
Poster de conférence
| Résumé : | The Antarctic Ice Sheet has undergone significant climate variability throughout glacial-interglacial cycles. Because thermal diffusion and advection rates are low, surface temperature anomalies propagate slowly to the base, imparting a thermal memory to ice sheets that persists for thousands of years. Since ice temperature controls viscosity, deformation rates, and subglacial processes, this inherited thermal structure exerts a direct influence on contemporary ice dynamics. Recent work on the thermal state of the Antarctic Ice Sheet (Raspoet & Pattyn, 2025) has explored uncertainties in boundary conditions and model approximations, but considered a thermal steady state, thereby assuming equilibrium with present-day climatic conditions and neglecting the legacy of past glacial-interglacial changes. In this study, we employ the thermomechanical ice-sheet model Kori-ULB, driven by reconstructed transient climate forcings spanning the last interglacial to the present day, to quantify the effects of paleoclimatic evolution on the thermal state of the Antarctic Ice Sheet and assess the implications for ice-sheet dynamics and model initialization. Results show that englacial temperatures are sensitive to the past climate history, leading to uncertainties of the same order as those related to the geothermal heat flow. Incorporating variations in surface temperatures and accumulation rates over the last glacial-interglacial cycle results in colder temperature profiles and basal thermal conditions, suggesting that steady-state ice-sheet models may overestimate present-day thermal conditions. |
