Year: 2025
Type: article
Abstract: . Societal adaptation to rising sea levels requires robust projections of the Antarctic Ice Sheet’s retreat, particularly due to ocean-driven basal melting of its fringing ice shelves. Recent advances in ocean models that simulate ice-shelf melting offer an opportunity to reduce uncertainties in ice–ocean interactions. Here, we compare several community-contributed, circum-Antarctic ocean simulations to highlight inter-model differences, evaluate agreement with satellite-derived melt rates, and examine underlying physical processes. All but one simulation use a melting formulation depending on both thermal driving (T ⋆) and friction velocity (u⋆), which together represent the thermal and ocean current forcings at the ice–ocean interface. Simulated melt rates range from 650 to 1277 Gt year−1 (m = 0.45 − 0.91 m year−1), driven by variations in model resolution, parameterisations, and sub-ice shelf circulation. Freeze-to-melt ratios span 0.30 to 30.12 %, indicating large differences in how refreezing is represented. The multi-model mean (MMM) produces an averaged melt rate of 0.60 m year−1 from a net mass loss of 842.99 Gt year−1 (876.03 Gt year−1 melting and 33.05 Gt year−1 refreezing), yielding a freeze-to-melt ratio of 3.92 %. We define a thermo-kinematic melt sensitivity, ζ = m/(T ⋆ u⋆) = 4.82 × 10−5 °C−1 for the MMM, with individual models spanning 2.85 × 10−5 to 19.4 × 10−5 °C−1. Higher melt rates typically occur near grounding zones where both T ⋆ and u⋆ exert roughly equal influence. Because friction velocity is critical for turbulent heat exchange, ice-shelf melting must be characterised by both ocean energetics and thermal forcing. Further work to standardise model setups and evaluation of results against in situ observations and satellite data will be essential for increasing model accuracy, reducing uncertainties, to improve our understanding of ice-shelf–ocean interactions and refine sea-level rise predictions.
Source: The cryosphere
Authors: Benjamin Keith Galton-Fenzi, Richard Porter-Smith, Sue Cook, Eva Cougnon, David E. Gwyther, Wilma G. C. Huneke, Madelaine G. Rosevear, Xylar Asay-Davis, Fabio Boeira Dias, Michael S. Dinniman, David Holland, Kazuya Kusahara, Kaitlin A. Naughten, Keith W. Nicholls, Charles Pelletier, Ole Richter, Helene L. Seroussi, Ralph Timmermann
Institutions: University of Tasmania, Australian Antarctic Division, Institute for Marine and Antarctic Studies, Australian Centre for Excellence in Antarctic Science, Integrated Marine Observing System, The University of Queensland, Australian National University, The University of Melbourne, Argonne National Laboratory, Los Alamos National Laboratory, UNSW Sydney, Old Dominion University, New York University, Japan Agency for Marine-Earth Science and Technology, British Antarctic Survey, UCLouvain, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, University of Rostock, Dartmouth College
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,574
Awards: G1175102054, G1705667592, Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula, The Australian Centre for Excellence in Antarctic Science, G5039026791, G5527375060, G8654076895, Decadal Predictability and vAriability of polar climate: the Role of AtMosphere- Ocean-cryosphere Multiscale inteRactions
OpenAlex ID: W4416976599