Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations
Ice shelves regulate the flow of the Antarctic ice sheet toward the ocean and its contribution to sea-level rise. Accurately monitoring the basal and surface melting of ice shelves is therefore essential for predicting the ice sheet's response to climatic warming. In this study, we utilize Sent...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2024-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143024000716/type/journal_article |
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| author | Jakob Stanley Hamann Thomas Arney James David Kirkham Paul Wachter Karsten Gohl |
| author_facet | Jakob Stanley Hamann Thomas Arney James David Kirkham Paul Wachter Karsten Gohl |
| author_sort | Jakob Stanley Hamann |
| collection | DOAJ |
| description | Ice shelves regulate the flow of the Antarctic ice sheet toward the ocean and its contribution to sea-level rise. Accurately monitoring the basal and surface melting of ice shelves is therefore essential for predicting the ice sheet's response to climatic warming. In this study, we utilize Sentinel-1A synthetic aperture radar satellite imagery combined with shipboard measurements of water temperature and salinity to investigate the presence of surficial meltwater plumes along the Antarctic coastline. Our approach reveals a strong correlation between areas of pronounced low radar backscatter extending from ice shelves and significant decreases in water temperature and salinity, suggesting meltwater-enriched ocean waters. We propose that the low radar backscatter signature of meltwater outflows is caused by stable stratification of the upper water column, driven by density contrasts from buoyant, low-salinity meltwater and surface current shear that reduce Bragg scattering waves. The resulting smooth water surfaces were observed adjacent to the surface expression of deep basal channels, documented in a helicopter survey along part of the Bellingshausen Sea ice edge. We present high-temporal resolution satellite radar as a tool for identifying meltwater release from beneath ice shelves, capable of all-weather, day-and-night imaging. |
| format | Article |
| id | doaj-art-6328c872606c4ad48c17328d17b55a4e |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Cambridge University Press |
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| series | Journal of Glaciology |
| spelling | doaj-art-6328c872606c4ad48c17328d17b55a4e2025-01-16T21:47:45ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.71Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observationsJakob Stanley Hamann0https://orcid.org/0009-0001-4051-1070Thomas Arney1https://orcid.org/0000-0003-4380-4079James David Kirkham2Paul Wachter3Karsten Gohl4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany Department of Earth Sciences, Physical Geography, Freie Universität Berlin, Berlin, GermanySchool of Ocean and Earth Science, University of Southampton, Southampton, UK British Antarctic Survey, Natural Environment Research Council, Cambridge, UKBritish Antarctic Survey, Natural Environment Research Council, Cambridge, UKGerman Remote Sensing Data Center (DFD), German Aerospace Center (DLR), Wessling, GermanyAlfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyIce shelves regulate the flow of the Antarctic ice sheet toward the ocean and its contribution to sea-level rise. Accurately monitoring the basal and surface melting of ice shelves is therefore essential for predicting the ice sheet's response to climatic warming. In this study, we utilize Sentinel-1A synthetic aperture radar satellite imagery combined with shipboard measurements of water temperature and salinity to investigate the presence of surficial meltwater plumes along the Antarctic coastline. Our approach reveals a strong correlation between areas of pronounced low radar backscatter extending from ice shelves and significant decreases in water temperature and salinity, suggesting meltwater-enriched ocean waters. We propose that the low radar backscatter signature of meltwater outflows is caused by stable stratification of the upper water column, driven by density contrasts from buoyant, low-salinity meltwater and surface current shear that reduce Bragg scattering waves. The resulting smooth water surfaces were observed adjacent to the surface expression of deep basal channels, documented in a helicopter survey along part of the Bellingshausen Sea ice edge. We present high-temporal resolution satellite radar as a tool for identifying meltwater release from beneath ice shelves, capable of all-weather, day-and-night imaging.https://www.cambridge.org/core/product/identifier/S0022143024000716/type/journal_articleglacier dischargeglaciological instruments and methodsice shelvesmelt – basalremote sensing |
| spellingShingle | Jakob Stanley Hamann Thomas Arney James David Kirkham Paul Wachter Karsten Gohl Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations Journal of Glaciology glacier discharge glaciological instruments and methods ice shelves melt – basal remote sensing |
| title | Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations |
| title_full | Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations |
| title_fullStr | Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations |
| title_full_unstemmed | Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations |
| title_short | Antarctic ice-shelf meltwater outflows in satellite radar imagery: ground-truthing and basal channel observations |
| title_sort | antarctic ice shelf meltwater outflows in satellite radar imagery ground truthing and basal channel observations |
| topic | glacier discharge glaciological instruments and methods ice shelves melt – basal remote sensing |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000716/type/journal_article |
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