Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice”
The oceanic connection between ice shelf cavities and sea ice influences sea ice development and persistence. One unique feature in regions near ice shelves is the potential for sea ice growth due to crystal accretion on its underside. Here we present observations of ocean boundary-layer processes a...
Published in: | Frontiers in Marine Science |
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2023
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Online Access: | http://dx.doi.org/10.3389/fmars.2023.1103740 https://www.frontiersin.org/articles/10.3389/fmars.2023.1103740/full |
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crfrontiers:10.3389/fmars.2023.1103740 2024-09-15T17:46:54+00:00 Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” Stevens, Craig Robinson, Natalie O’Connor, Gabby Grant, Brett 2023 http://dx.doi.org/10.3389/fmars.2023.1103740 https://www.frontiersin.org/articles/10.3389/fmars.2023.1103740/full unknown Frontiers Media SA https://creativecommons.org/licenses/by/4.0/ Frontiers in Marine Science volume 10 ISSN 2296-7745 journal-article 2023 crfrontiers https://doi.org/10.3389/fmars.2023.1103740 2024-07-09T04:05:08Z The oceanic connection between ice shelf cavities and sea ice influences sea ice development and persistence. One unique feature in regions near ice shelves is the potential for sea ice growth due to crystal accretion on its underside. Here we present observations of ocean boundary-layer processes and ice crystal behaviour in an Ice Shelf Water outflow region from the Ross/McMurdo Ice Shelves. From a fast ice field camp during the Spring of 2015, we captured the kinematics of free-floating relatively large (in some cases 10s of mm in scale) ice crystals that were advecting and then settling upwards in a depositional layer on the sea ice underside (SIPL, sub-ice platelet layer). Simultaneously, we measured the background oceanic temperature, salinity, currents and turbulence structure. At the camp location the total water depth was 536 m, with the uppermost 50 m of the water column being in-situ super-cooled. Tidal flow speeds had an amplitude of around 0.1 m s -1 with dissipation rates in the under-ice boundary layer measured to be up to ε=10 -6 W kg -1 . Acoustic sampling (200 kHz) identified backscatter from large, individually identifiable suspended crystals associated with crystal sizes larger than normally described as frazil. Measurement of crystals in the SIPL found dimensions of the range 5-200 mm with an average of 93-101 mm depending on the year. The existence and settlement of crystals has implications for understanding SIPL evolution, the structure of sea ice, as well as the fate of Ice Shelf Water. Article in Journal/Newspaper Antarc* Antarctic Ice Shelf Ice Shelves Sea ice Frontiers (Publisher) Frontiers in Marine Science 10 |
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The oceanic connection between ice shelf cavities and sea ice influences sea ice development and persistence. One unique feature in regions near ice shelves is the potential for sea ice growth due to crystal accretion on its underside. Here we present observations of ocean boundary-layer processes and ice crystal behaviour in an Ice Shelf Water outflow region from the Ross/McMurdo Ice Shelves. From a fast ice field camp during the Spring of 2015, we captured the kinematics of free-floating relatively large (in some cases 10s of mm in scale) ice crystals that were advecting and then settling upwards in a depositional layer on the sea ice underside (SIPL, sub-ice platelet layer). Simultaneously, we measured the background oceanic temperature, salinity, currents and turbulence structure. At the camp location the total water depth was 536 m, with the uppermost 50 m of the water column being in-situ super-cooled. Tidal flow speeds had an amplitude of around 0.1 m s -1 with dissipation rates in the under-ice boundary layer measured to be up to ε=10 -6 W kg -1 . Acoustic sampling (200 kHz) identified backscatter from large, individually identifiable suspended crystals associated with crystal sizes larger than normally described as frazil. Measurement of crystals in the SIPL found dimensions of the range 5-200 mm with an average of 93-101 mm depending on the year. The existence and settlement of crystals has implications for understanding SIPL evolution, the structure of sea ice, as well as the fate of Ice Shelf Water. |
format |
Article in Journal/Newspaper |
author |
Stevens, Craig Robinson, Natalie O’Connor, Gabby Grant, Brett |
spellingShingle |
Stevens, Craig Robinson, Natalie O’Connor, Gabby Grant, Brett Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” |
author_facet |
Stevens, Craig Robinson, Natalie O’Connor, Gabby Grant, Brett |
author_sort |
Stevens, Craig |
title |
Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” |
title_short |
Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” |
title_full |
Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” |
title_fullStr |
Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” |
title_full_unstemmed |
Ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an Antarctic ice shelf water plume: The “dirty ice” |
title_sort |
ocean turbulent boundary-layer influence on ice crystal behaviour beneath fast ice in an antarctic ice shelf water plume: the “dirty ice” |
publisher |
Frontiers Media SA |
publishDate |
2023 |
url |
http://dx.doi.org/10.3389/fmars.2023.1103740 https://www.frontiersin.org/articles/10.3389/fmars.2023.1103740/full |
genre |
Antarc* Antarctic Ice Shelf Ice Shelves Sea ice |
genre_facet |
Antarc* Antarctic Ice Shelf Ice Shelves Sea ice |
op_source |
Frontiers in Marine Science volume 10 ISSN 2296-7745 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3389/fmars.2023.1103740 |
container_title |
Frontiers in Marine Science |
container_volume |
10 |
_version_ |
1810495325985570816 |