Sensitivity of the Antarctic ice sheets to the warming of marine isotope substage 11c

• DOI: 10.5194/tc-15-459-2021
• Publication Date: 2021-01-28T18:06:35Z
• Authors: Martim Mas e Braga; Jorge Bernales; Matthias Prange; Arjen P. Stroeven; Irina Rogozhina
• Keywords: Antarctic ice sheet; Ice-sheet model; Ice core

Abstract. Studying the response of Antarctic ice sheets during periods when climate conditions were similar to present can provide important insights into current observed changes and help identify natural drivers sheet retreat. In this context, marine isotope substage 11c (MIS11c) interglacial offers a suitable scenario, given that its later portion orbital parameters close our interglacial. Ice core data indicate warmer-than-present temperatures lasted for longer than other interglacials. However, their contribution sea level rise remain unclear. We explore dynamics period using numerical model forced by MIS11c derived from outputs scaled three glaciological one sedimentary proxy records volume. Our results East West contributed 4.0–8.2 m rise. case Sheet collapse, which is most probable scenario according far-field reconstructions, range reduced 6.7–8.2 independently choices external forcing millennial-scale variability. Within latter range, main source uncertainty arises sensitivity choice initial configuration. found warmer regional signal captured cores peak crucial reproduce expected Antarctica recorded global highstand. This translates modest threshold 0.4 ∘C oceanic warming at intermediate depths, leads collapse if sustained least 4000 years.