Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean
The low levels of mechanically driven mixing in many regions of the Arctic Ocean make double diffusive convection virtually the only mechanism for moving heat up from the core of Atlantic Water towards the surface. In an attempt to quantify double diffusive heat fluxes in the Arctic Ocean, a tempera...
Published in: | Journal of Geophysical Research: Oceans |
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Language: | English |
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Online Access: | https://hdl.handle.net/1956/17679 https://doi.org/10.1002/2015jc010884 |
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ftunivbergen:oai:bora.uib.no:1956/17679 2023-05-15T13:22:41+02:00 Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean Guthrie, John D. Fer, Ilker Morison, James H. 2018-01-02T10:36:27Z application/pdf https://hdl.handle.net/1956/17679 https://doi.org/10.1002/2015jc010884 eng eng American Geophysical Union Norges forskningsråd: 229786 urn:issn:2169-9291 urn:issn:2169-9275 https://hdl.handle.net/1956/17679 https://doi.org/10.1002/2015jc010884 cristin:1259820 Copyright 2015. American Geophysical Union. All Rights Reserved. Journal of Geophysical Research - Oceans Peer reviewed Journal article 2018 ftunivbergen https://doi.org/10.1002/2015jc010884 2023-03-14T17:45:03Z The low levels of mechanically driven mixing in many regions of the Arctic Ocean make double diffusive convection virtually the only mechanism for moving heat up from the core of Atlantic Water towards the surface. In an attempt to quantify double diffusive heat fluxes in the Arctic Ocean, a temperature microstructure experiment was performed as a part of the North Pole Environmental Observatory (NPEO) 2013 field season from the drifting ice station Barneo located in the Amundsen Basin near the Lomonosov Ridge (89.58N, 758W). A diffusive convective thermohaline staircase was present between 150 and 250 m in nearly all of the profiles. Typical vertical heat fluxes across the high-gradient interfaces were consistently small, O(1021 )Wm22 . Our experiment was designed to resolve the staircase and differed from earlier Arctic studies that utilized inadequate instrumentation or sampling. Our measured fluxes from temperature microstructure agree well with the laboratory derived flux laws compared to previous studies, which could find agreement only to within a factor of two to four. Correlations between measured and parameterized heat fluxes are slightly higher when using the more recent Flanagan et al. [2013] laboratory derivation than the more commonly used derivation presented in Kelley [1990]. Nusselt versus Rayleigh number scaling reveals the convective exponent, g, to be closer to 0.29 as predicted by recent numerical simulations of single-component convection rather than the canonical 1/3 assumed for double diffusion. However, the exponent appears to be sensitive to how convective layer height is defined. publishedVersion Article in Journal/Newspaper amundsen basin Arctic Arctic Ocean Lomonosov Ridge North Pole University of Bergen: Bergen Open Research Archive (BORA-UiB) Amundsen Basin ENVELOPE(74.000,74.000,87.000,87.000) Arctic Arctic Ocean North Pole Journal of Geophysical Research: Oceans 120 12 7880 7896 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
The low levels of mechanically driven mixing in many regions of the Arctic Ocean make double diffusive convection virtually the only mechanism for moving heat up from the core of Atlantic Water towards the surface. In an attempt to quantify double diffusive heat fluxes in the Arctic Ocean, a temperature microstructure experiment was performed as a part of the North Pole Environmental Observatory (NPEO) 2013 field season from the drifting ice station Barneo located in the Amundsen Basin near the Lomonosov Ridge (89.58N, 758W). A diffusive convective thermohaline staircase was present between 150 and 250 m in nearly all of the profiles. Typical vertical heat fluxes across the high-gradient interfaces were consistently small, O(1021 )Wm22 . Our experiment was designed to resolve the staircase and differed from earlier Arctic studies that utilized inadequate instrumentation or sampling. Our measured fluxes from temperature microstructure agree well with the laboratory derived flux laws compared to previous studies, which could find agreement only to within a factor of two to four. Correlations between measured and parameterized heat fluxes are slightly higher when using the more recent Flanagan et al. [2013] laboratory derivation than the more commonly used derivation presented in Kelley [1990]. Nusselt versus Rayleigh number scaling reveals the convective exponent, g, to be closer to 0.29 as predicted by recent numerical simulations of single-component convection rather than the canonical 1/3 assumed for double diffusion. However, the exponent appears to be sensitive to how convective layer height is defined. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Guthrie, John D. Fer, Ilker Morison, James H. |
spellingShingle |
Guthrie, John D. Fer, Ilker Morison, James H. Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean |
author_facet |
Guthrie, John D. Fer, Ilker Morison, James H. |
author_sort |
Guthrie, John D. |
title |
Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean |
title_short |
Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean |
title_full |
Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean |
title_fullStr |
Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean |
title_full_unstemmed |
Observational validation of the diffusive convection flux laws in the Amundsen Basin, Arctic Ocean |
title_sort |
observational validation of the diffusive convection flux laws in the amundsen basin, arctic ocean |
publisher |
American Geophysical Union |
publishDate |
2018 |
url |
https://hdl.handle.net/1956/17679 https://doi.org/10.1002/2015jc010884 |
long_lat |
ENVELOPE(74.000,74.000,87.000,87.000) |
geographic |
Amundsen Basin Arctic Arctic Ocean North Pole |
geographic_facet |
Amundsen Basin Arctic Arctic Ocean North Pole |
genre |
amundsen basin Arctic Arctic Ocean Lomonosov Ridge North Pole |
genre_facet |
amundsen basin Arctic Arctic Ocean Lomonosov Ridge North Pole |
op_source |
Journal of Geophysical Research - Oceans |
op_relation |
Norges forskningsråd: 229786 urn:issn:2169-9291 urn:issn:2169-9275 https://hdl.handle.net/1956/17679 https://doi.org/10.1002/2015jc010884 cristin:1259820 |
op_rights |
Copyright 2015. American Geophysical Union. All Rights Reserved. |
op_doi |
https://doi.org/10.1002/2015jc010884 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
120 |
container_issue |
12 |
container_start_page |
7880 |
op_container_end_page |
7896 |
_version_ |
1766366317307232256 |