[M-IS10] Global climate change driven by the Southern Ocean and the Antarctic Ice Sheet

[MIS10-12] Changes in the ice sheet of the Wilkes subglacial basin and the high-latitude Southern Ocean during the Last Interglacial

★Invited Papers

*Mutusmi Iizuka¹, Osamu Seki², David J Wilson³, Yusuke Suganuma⁴, Keiji Horikawa⁵, Tina van de Flierdt⁶, Minoru Ikehara⁷, Takuya Itaki¹, Tomohisa Irino², Masanobu Yamamoto², Motohiro Hirabayashi⁴, Hiroyuki Matsuzaki⁸, Saiko Sugisaki¹, Ryosuke Makabe⁴, Motoha Ojima⁴, Shigeru Aoki² (1.The National Institute of Advanced Industrial Science and Technology, 2.Hokkaido University, 3.University College London, 4.National Institute of Polar Research, 5.University of Toyama, 6.Imperial College London, London, 7.Kochi University, 8.The University of Tokyo)

Keywords:Antarctic Ice Sheet, Southern Ocean, Last Interglacial

In recent decades, the Antarctic ice sheet has experienced rapid melting. This raises concerns about significant sea level rise in future warming scenarios, but projections regarding ice sheet shrinkage have remained uncertain. To improve the accuracy of future sea level predictions, it is crucial to understand the long-term behavior of the Antarctic ice sheet under warm climate conditions. Of particular importance is investigating areas where the bedrock lies below sea level, as such marine-based ice sheets are vulnerable to ocean warming, such as the intrusion of relatively warm Circumpolar Deep Water (CDW) beneath ice shelves. This phenomenon can lead to an increase in grounded ice discharge, contributing to sea-level rise. Therefore, a better understanding of the sensitivity of the ice sheet in these regions in response to climate warming is crucial for accurately estimating the potential sea level rise in future warming scenarios.
The Last Interglacial period (LIG: 130,000–115,000 years ago), characterized by approximately 1ºC higher temperatures compared to the preindustrial level, provides valuable insights into the response of marine-based ice sheets under warm conditions. During the LIG, it is thought that sea levels were several meters higher than present levels, indicating a significant loss of polar Antarctic ice-sheet mass. However, due to the lack of detailed records of ocean and ice sheet variability during the LIG, the link between these two climate sub-components has remained uncertain. In this presentation, we will share the outcomes of our research on the changes in the Antarctic ice sheet and the Southern Ocean during the LIG and present future prospects.