Seafloor roughness reduces melting of East Antarctic ice shelves

• Published in: Communications Earth & Environment
• Main Authors: Yuhang Liu, Maxim Nikurashin, Beatriz Peña-Molino
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Portfolio 2024
• Subjects: Geology; QE1-996.5; Environmental sciences; GE1-350; Antarc*; Antarctic; Antarctica; Denman Glacier; Ice Sheet; Ice Shelf; Ice Shelves
• Online Access: https://doi.org/10.1038/s43247-024-01480-x; https://doaj.org/article/f798f2ac11314b83887c422b93b63fd2

Abstract Heat delivered by the ocean circulation is melting the Antarctic ice sheet from below. This melt is largest where warm Circumpolar Deep Water accesses the continental shelf and reaches the ice shelf cavities. Future melt rate projections are based on ocean thermal forcing derived from climate models, which tend to be biased warm around Antarctica. The bias has been attributed to unresolved ocean processes that occur at scales poorly represented in models. Using a high-resolution model of the Denman Glacier region we show that seafloor roughness unresolved in climate models suppresses the impact of warm water on ice sheet melting. Seafloor roughness slows down the shelf circulation, reducing the presence of warm water over the shelf and the heat transport towards the ice cavities. As a result, the total meltwater discharge drops by 4 Gt year−1. Our results suggest a mechanism missing in global ocean and climate models that could reduce the spread in climate projections.