Pathways of ocean heat towards Pine Island and Thwaites grounding lines

• Published in: Scientific Reports
• Main Authors: Nakayama, Yoshihiro, Manucharyan, Georgy, Zhang, Hong, Dutrieux, Pierre, Torres, Hector S., Klein, Patrice, Seroussi, Helene, Schodlok, Michael, Rignot, Eric, Menemenlis, Dimitris
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Nature Publishing Group 2019
• Subjects: Amundsen Sea; Antarctic; Austral; Antarc*; Ice Sheet; Ice Shelf
• Online Access: https://doi.org/10.1038/s41598-019-53190-6; https://www.ncbi.nlm.nih.gov/pmc/PMC6874652

In the Amundsen Sea, modified Circumpolar Deep Water (mCDW) intrudes into ice shelf cavities, causing high ice shelf melting near the ice sheet grounding lines, accelerating ice flow, and controlling the pace of future Antarctic contributions to global sea level. The pathways of mCDW towards grounding lines are crucial as they directly control the heat reaching the ice. A realistic representation of mCDW circulation, however, remains challenging due to the sparsity of in-situ observations and the difficulty of ocean models to reproduce the available observations. In this study, we use an unprecedentedly high-resolution (200 m horizontal and 10 m vertical grid spacing) ocean model that resolves shelf-sea and sub-ice-shelf environments in qualitative agreement with existing observations during austral summer conditions. We demonstrate that the waters reaching the Pine Island and Thwaites grounding lines follow specific, topographically-constrained routes, all passing through a relatively small area located around 104°W and 74.3°S. The temporal and spatial variabilities of ice shelf melt rates are dominantly controlled by the sub-ice shelf ocean current. Our findings highlight the importance of accurate and high-resolution ocean bathymetry and subglacial topography for determining mCDW pathways and ice shelf melt rates. © 2019 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the ...