Inter-decadal climate variability induces differential ice response along Pacific-facing West Antarctica.

• Main Authors: Christie, Frazer DW, Steig, Eric J, Gourmelen, Noel, Tett, Simon FB, Bingham, Robert G
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2023
• Subjects: Article; /704/106/125; /704/106/829/2737; /123; /134; /139; /119; Amundsen Sea; Antarctic; Bellingshausen Sea; Pacific; Southern Ocean; The Antarctic; West Antarctica; Antarc*; Antarctica; Ice Sheet; Pine Island
• Online Access: https://doi.org/10.17863/CAM.92825; https://www.repository.cam.ac.uk/handle/1810/345403

Funder: Carnegie Trust for the Universities of Scotland; doi: https://doi.org/10.13039/501100000582 Funder: Prince Albert II of Monaco Foundation (Prince Albert II Foundation); doi: https://doi.org/10.13039/501100011592 Funder: Scottish Alliance for Geoscience, Environment and Society (SAGES); doi: https://doi.org/10.13039/100008083 West Antarctica has experienced dramatic ice losses contributing to global sea-level rise in recent decades, particularly from Pine Island and Thwaites glaciers. Although these ice losses manifest an ongoing Marine Ice Sheet Instability, projections of their future rate are confounded by limited observations along West Antarctica's coastal perimeter with respect to how the pace of retreat can be modulated by variations in climate forcing. Here, we derive a comprehensive, 12-year record of glacier retreat around West Antarctica's Pacific-facing margin and compare this dataset to contemporaneous estimates of ice flow, mass loss, the state of the Southern Ocean and the atmosphere. Between 2003 and 2015, rates of glacier retreat and acceleration were extensive along the Bellingshausen Sea coastline, but slowed along the Amundsen Sea. We attribute this to an interdecadal suppression of westerly winds in the Amundsen Sea, which reduced warm water inflow to the Amundsen Sea Embayment. Our results provide direct observations that the pace, magnitude and extent of ice destabilization around West Antarctica vary by location, with the Amundsen Sea response most sensitive to interdecadal atmosphere-ocean variability. Thus, model projections accounting for regionally resolved ice-ocean-atmosphere interactions will be important for predicting accurately the short-term evolution of the Antarctic Ice Sheet. Carnegie Trust for the Universities of Scotland Carnegie PhD Scholarship Scottish Alliance for Geoscience, Environment and Society (SAGES) Prince Albert II of Monaco Foundation NSF Grant 2045075 European Space Agency