Ross Gyre variability modulates oceanic heat supply toward the West Antarctic continental shelf

• Published in: Communications Earth & Environment
• Main Authors: Channing J. Prend, Graeme A. MacGilchrist, Georgy E. Manucharyan, Rachel Q. Pang, Ruth Moorman, Andrew F. Thompson, Stephen M. Griffies, Matthew R. Mazloff, Lynne D. Talley, Sarah T. Gille
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2024
• Subjects: Geology; QE1-996.5; Environmental sciences; GE1-350; Amundsen Sea; Antarc*; Antarctic; Ice Sheet; Sea ice; Southern Ocean
• Online Access: https://doi.org/10.1038/s43247-024-01207-y; https://doaj.org/article/fddfcce3295940d2ac53309d3a428876

Abstract West Antarctic Ice Sheet mass loss is a major source of uncertainty in sea level projections. The primary driver of this melting is oceanic heat from Circumpolar Deep Water originating offshore in the Antarctic Circumpolar Current. Yet, in assessing melt variability, open ocean processes have received considerably less attention than those governing cross-shelf exchange. Here, we use Lagrangian particle release experiments in an ocean model to investigate the pathways by which Circumpolar Deep Water moves toward the continental shelf across the Pacific sector of the Southern Ocean. We show that Ross Gyre expansion, linked to wind and sea ice variability, increases poleward heat transport along the gyre’s eastern limb and the relative fraction of transport toward the Amundsen Sea. Ross Gyre variability, therefore, influences oceanic heat supply toward the West Antarctic continental slope. Understanding remote controls on basal melt is necessary to predict the ice sheet response to anthropogenic forcing.