Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica
The first turbulence profiler observations beneath land fast sea ice which is directly adjacent to an Antarctic ice shelf are described. The stratification in the 325 m deep water column consisted of a layer of supercooled water in the upper 40 m lying above a quasi-linearly stratified water column...
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Copernicus Publications
2009
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00029662 2023-05-15T13:36:44+02:00 Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica Stevens, C. L. Robinson, N. J. Williams, M. J. M. Haskell, T. G. 2009-10 electronic https://doi.org/10.5194/os-5-435-2009 https://noa.gwlb.de/receive/cop_mods_00029662 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029617/os-5-435-2009.pdf https://os.copernicus.org/articles/5/435/2009/os-5-435-2009.pdf eng eng Copernicus Publications Ocean Science -- http://www.bibliothek.uni-regensburg.de/ezeit/?2183769 -- http://www.copernicus.org/EGU/os/os.html -- 1812-0792 https://doi.org/10.5194/os-5-435-2009 https://noa.gwlb.de/receive/cop_mods_00029662 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029617/os-5-435-2009.pdf https://os.copernicus.org/articles/5/435/2009/os-5-435-2009.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2009 ftnonlinearchiv https://doi.org/10.5194/os-5-435-2009 2022-02-08T22:47:36Z The first turbulence profiler observations beneath land fast sea ice which is directly adjacent to an Antarctic ice shelf are described. The stratification in the 325 m deep water column consisted of a layer of supercooled water in the upper 40 m lying above a quasi-linearly stratified water column with a sharp step in density at mid-depth. Turbulent energy dissipation rates were on average 3×10−8 m2 s−3 with peak bin-averaged values reaching 4×10−7 m2 s−3. The local dissipation rate per unit area was estimated to be 10 m Wm−2 on average with a peak of 50 m Wm−2. These values are consistent with a moderate baroclinic response to the tides. The small-scale turbulent energetics lie on the boundary between isotropy and buoyancy-affected. This will likely influence the formation and aggregation of frazil ice crystals within the supercooled layer. The data suggest that the large crystals observed in McMurdo Sound will transition from initial growth at scales smaller than the Kolmogorov lengthscale to sizes substantially (1–2 orders of magnitude) greater than the Kolmogorov scale. An estimate of the experiment-averaged vertical diffusivity of mass Kρ yields a coefficient of around 2×10−4 m2s−1 although this increased by a factor of 2 near the surface. Combining this estimate of Kρ with available observations of average and maximum currents suggests the layer of supercooled water can persist for a distance of ~250 km from the front of the McMurdo Ice Shelf. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Shelf McMurdo Ice Shelf McMurdo Sound Sea ice Niedersächsisches Online-Archiv NOA Antarctic McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) McMurdo Sound Ocean Science 5 4 435 445 |
institution |
Open Polar |
collection |
Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Stevens, C. L. Robinson, N. J. Williams, M. J. M. Haskell, T. G. Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica |
topic_facet |
article Verlagsveröffentlichung |
description |
The first turbulence profiler observations beneath land fast sea ice which is directly adjacent to an Antarctic ice shelf are described. The stratification in the 325 m deep water column consisted of a layer of supercooled water in the upper 40 m lying above a quasi-linearly stratified water column with a sharp step in density at mid-depth. Turbulent energy dissipation rates were on average 3×10−8 m2 s−3 with peak bin-averaged values reaching 4×10−7 m2 s−3. The local dissipation rate per unit area was estimated to be 10 m Wm−2 on average with a peak of 50 m Wm−2. These values are consistent with a moderate baroclinic response to the tides. The small-scale turbulent energetics lie on the boundary between isotropy and buoyancy-affected. This will likely influence the formation and aggregation of frazil ice crystals within the supercooled layer. The data suggest that the large crystals observed in McMurdo Sound will transition from initial growth at scales smaller than the Kolmogorov lengthscale to sizes substantially (1–2 orders of magnitude) greater than the Kolmogorov scale. An estimate of the experiment-averaged vertical diffusivity of mass Kρ yields a coefficient of around 2×10−4 m2s−1 although this increased by a factor of 2 near the surface. Combining this estimate of Kρ with available observations of average and maximum currents suggests the layer of supercooled water can persist for a distance of ~250 km from the front of the McMurdo Ice Shelf. |
format |
Article in Journal/Newspaper |
author |
Stevens, C. L. Robinson, N. J. Williams, M. J. M. Haskell, T. G. |
author_facet |
Stevens, C. L. Robinson, N. J. Williams, M. J. M. Haskell, T. G. |
author_sort |
Stevens, C. L. |
title |
Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica |
title_short |
Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica |
title_full |
Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica |
title_fullStr |
Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica |
title_full_unstemmed |
Observations of turbulence beneath sea ice in southern McMurdo Sound, Antarctica |
title_sort |
observations of turbulence beneath sea ice in southern mcmurdo sound, antarctica |
publisher |
Copernicus Publications |
publishDate |
2009 |
url |
https://doi.org/10.5194/os-5-435-2009 https://noa.gwlb.de/receive/cop_mods_00029662 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029617/os-5-435-2009.pdf https://os.copernicus.org/articles/5/435/2009/os-5-435-2009.pdf |
long_lat |
ENVELOPE(166.500,166.500,-78.000,-78.000) |
geographic |
Antarctic McMurdo Ice Shelf McMurdo Sound |
geographic_facet |
Antarctic McMurdo Ice Shelf McMurdo Sound |
genre |
Antarc* Antarctic Antarctica Ice Shelf McMurdo Ice Shelf McMurdo Sound Sea ice |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelf McMurdo Ice Shelf McMurdo Sound Sea ice |
op_relation |
Ocean Science -- http://www.bibliothek.uni-regensburg.de/ezeit/?2183769 -- http://www.copernicus.org/EGU/os/os.html -- 1812-0792 https://doi.org/10.5194/os-5-435-2009 https://noa.gwlb.de/receive/cop_mods_00029662 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00029617/os-5-435-2009.pdf https://os.copernicus.org/articles/5/435/2009/os-5-435-2009.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/os-5-435-2009 |
container_title |
Ocean Science |
container_volume |
5 |
container_issue |
4 |
container_start_page |
435 |
op_container_end_page |
445 |
_version_ |
1766083073501298688 |