Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica

<p>Basal melting of Antarctic ice shelves significantly contributes to ice sheet mass loss, with distinct regional disparities in melt rates driven by ocean properties. In Dronning Maud Land (DML), East Antarctica, cold water predominantly fills the ice shelf cavities, resulting in generally l...

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Main Authors: O. Zeising, T. Hattermann, L. Kaleschke, S. Berger, O. Boebel, R. Drews, M. R. Ershadi, T. Fromm, F. Pattyn, D. Steinhage, O. Eisen
Format: Article
Language:English
Published: Copernicus Publications 2025-08-01
Series:The Cryosphere
Online Access:https://tc.copernicus.org/articles/19/2837/2025/tc-19-2837-2025.pdf
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author O. Zeising
T. Hattermann
L. Kaleschke
S. Berger
S. Berger
O. Boebel
R. Drews
M. R. Ershadi
T. Fromm
F. Pattyn
D. Steinhage
O. Eisen
O. Eisen
author_facet O. Zeising
T. Hattermann
L. Kaleschke
S. Berger
S. Berger
O. Boebel
R. Drews
M. R. Ershadi
T. Fromm
F. Pattyn
D. Steinhage
O. Eisen
O. Eisen
author_sort O. Zeising
collection DOAJ
description <p>Basal melting of Antarctic ice shelves significantly contributes to ice sheet mass loss, with distinct regional disparities in melt rates driven by ocean properties. In Dronning Maud Land (DML), East Antarctica, cold water predominantly fills the ice shelf cavities, resulting in generally low annual melt rates. In this study, we present a 4-year record of basal melt rates at the Ekström Ice Shelf, measured using an autonomous phase-sensitive radio-echo sounder (ApRES). Observations reveal a low mean annual melt rate of 0.44 <span class="inline-formula">m a<sup>−1</sup></span>, with a seasonal variability. Enhanced melting occurs in winter and spring, peaking at over 1 <span class="inline-formula">m a<sup>−1</sup></span>, while rates are decreased in summer and autumn. We hypothesise that the dense water formed during sea-ice formation erodes the water column stratification during late winter and spring, leading to an increase in the buoyancy of the ice shelf water plume. An idealised plume model supports this hypothesis, indicating that the plume velocity is the primary driver of seasonal basal melt rate variability, while changes in ambient water temperature play a secondary role in the range of oceanographic conditions that are observed below the Ekström Ice Shelf. These findings offer new insights into the dynamics of ice–ocean interactions in East Antarctica, emphasising the need for further observations to refine our understanding of ocean variability within ice shelf cavities and improve assessments of ice shelf mass balance.</p>
format Article
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institution Kabale University
issn 1994-0416
1994-0424
language English
publishDate 2025-08-01
publisher Copernicus Publications
record_format Article
series The Cryosphere
spelling doaj-art-a704a2f72a3e4e218352e5e8049549662025-08-20T04:00:45ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242025-08-01192837285410.5194/tc-19-2837-2025Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East AntarcticaO. Zeising0T. Hattermann1L. Kaleschke2S. Berger3S. Berger4O. Boebel5R. Drews6M. R. Ershadi7T. Fromm8F. Pattyn9D. Steinhage10O. Eisen11O. Eisen12Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyResearch Department, Section for Oceanography, Norwegian Polar Institute, Tromsø, NorwayAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germanynow at: European Commission, Brussels, BelgiumAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyDepartment of Geosciences, University of Tübingen, Tübingen, GermanyDepartment of Geosciences, University of Tübingen, Tübingen, GermanyAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyLaboratoire de Glaciologie, Université Libre de Bruxelles, Brussels, BelgiumAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyAlfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, GermanyFaculty of Geosciences, University of Bremen, Bremen, Germany<p>Basal melting of Antarctic ice shelves significantly contributes to ice sheet mass loss, with distinct regional disparities in melt rates driven by ocean properties. In Dronning Maud Land (DML), East Antarctica, cold water predominantly fills the ice shelf cavities, resulting in generally low annual melt rates. In this study, we present a 4-year record of basal melt rates at the Ekström Ice Shelf, measured using an autonomous phase-sensitive radio-echo sounder (ApRES). Observations reveal a low mean annual melt rate of 0.44 <span class="inline-formula">m a<sup>−1</sup></span>, with a seasonal variability. Enhanced melting occurs in winter and spring, peaking at over 1 <span class="inline-formula">m a<sup>−1</sup></span>, while rates are decreased in summer and autumn. We hypothesise that the dense water formed during sea-ice formation erodes the water column stratification during late winter and spring, leading to an increase in the buoyancy of the ice shelf water plume. An idealised plume model supports this hypothesis, indicating that the plume velocity is the primary driver of seasonal basal melt rate variability, while changes in ambient water temperature play a secondary role in the range of oceanographic conditions that are observed below the Ekström Ice Shelf. These findings offer new insights into the dynamics of ice–ocean interactions in East Antarctica, emphasising the need for further observations to refine our understanding of ocean variability within ice shelf cavities and improve assessments of ice shelf mass balance.</p>https://tc.copernicus.org/articles/19/2837/2025/tc-19-2837-2025.pdf
spellingShingle O. Zeising
T. Hattermann
L. Kaleschke
S. Berger
S. Berger
O. Boebel
R. Drews
M. R. Ershadi
T. Fromm
F. Pattyn
D. Steinhage
O. Eisen
O. Eisen
Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica
The Cryosphere
title Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica
title_full Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica
title_fullStr Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica
title_full_unstemmed Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica
title_short Enhanced basal melting in winter and spring: seasonal ice–ocean interactions at the Ekström Ice Shelf, East Antarctica
title_sort enhanced basal melting in winter and spring seasonal ice ocean interactions at the ekstrom ice shelf east antarctica
url https://tc.copernicus.org/articles/19/2837/2025/tc-19-2837-2025.pdf
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