Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline
Renewal rates of the waters of the thermocline in the eastern North Atlantic are estimated by combining linear quasi-geostrophic dynamics with steady and transient tracers into a unified eclectic, reservoir model. The two-dimensional model first employed is finally rejected when it is found that it...
Published in: | Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences |
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1988
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Online Access: | http://dx.doi.org/10.1098/rsta.1988.0052 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1988.0052 |
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crroyalsociety:10.1098/rsta.1988.0052 2024-06-02T08:11:13+00:00 Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline 1988 http://dx.doi.org/10.1098/rsta.1988.0052 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1988.0052 en eng The Royal Society https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences volume 325, issue 1583, page 201-236 ISSN 0080-4614 2054-0272 journal-article 1988 crroyalsociety https://doi.org/10.1098/rsta.1988.0052 2024-05-07T14:16:38Z Renewal rates of the waters of the thermocline in the eastern North Atlantic are estimated by combining linear quasi-geostrophic dynamics with steady and transient tracers into a unified eclectic, reservoir model. The two-dimensional model first employed is finally rejected when it is found that it generates oxygen-utilization rates (OUR) that are, by conventional biological wisdom, too high. The three-dimensional model that replaces the two-dimensional one shows that the our is indeterminate, with possible ranges from zero to unacceptably high values. The region is flushed primarily from the north and east. The problem of using transient tracers is mathematically equivalent to that of distributed-system boundary-control theory, the open-ocean boundary conditions playing the role of the unknown control variables. The missing time histories of this new set of unknowns means that tritium and helium-3 distributions are only comparatively weak constraints on the flow field, but do set upper bounds on the vertical exchange with surface waters. Surface Ekman pumping is adequate to explain the interior distributions without additional buoyancy ventilation, although this latter process is possible. Some speculation is made about conditions under which transient tracers might play a more definitive role. Article in Journal/Newspaper North Atlantic The Royal Society Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences 325 1583 201 236 |
institution |
Open Polar |
collection |
The Royal Society |
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crroyalsociety |
language |
English |
description |
Renewal rates of the waters of the thermocline in the eastern North Atlantic are estimated by combining linear quasi-geostrophic dynamics with steady and transient tracers into a unified eclectic, reservoir model. The two-dimensional model first employed is finally rejected when it is found that it generates oxygen-utilization rates (OUR) that are, by conventional biological wisdom, too high. The three-dimensional model that replaces the two-dimensional one shows that the our is indeterminate, with possible ranges from zero to unacceptably high values. The region is flushed primarily from the north and east. The problem of using transient tracers is mathematically equivalent to that of distributed-system boundary-control theory, the open-ocean boundary conditions playing the role of the unknown control variables. The missing time histories of this new set of unknowns means that tritium and helium-3 distributions are only comparatively weak constraints on the flow field, but do set upper bounds on the vertical exchange with surface waters. Surface Ekman pumping is adequate to explain the interior distributions without additional buoyancy ventilation, although this latter process is possible. Some speculation is made about conditions under which transient tracers might play a more definitive role. |
format |
Article in Journal/Newspaper |
title |
Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline |
spellingShingle |
Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline |
title_short |
Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline |
title_full |
Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline |
title_fullStr |
Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline |
title_full_unstemmed |
Eclectic modelling of the North Atlantic. II. Transient tracers and the ventilation of the Eastern Basin thermocline |
title_sort |
eclectic modelling of the north atlantic. ii. transient tracers and the ventilation of the eastern basin thermocline |
publisher |
The Royal Society |
publishDate |
1988 |
url |
http://dx.doi.org/10.1098/rsta.1988.0052 https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1988.0052 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences volume 325, issue 1583, page 201-236 ISSN 0080-4614 2054-0272 |
op_rights |
https://royalsociety.org/journals/ethics-policies/data-sharing-mining/ |
op_doi |
https://doi.org/10.1098/rsta.1988.0052 |
container_title |
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences |
container_volume |
325 |
container_issue |
1583 |
container_start_page |
201 |
op_container_end_page |
236 |
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1800757292124078080 |