| Registro completo |
| Provedor de dados: |
ArchiMer
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| País: |
France
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| Título: |
A New Mechanism for Mode Water Formation involving Cabbeling and Frontogenetic Strain at Thermohaline Fronts
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| Autores: |
Thomas, Leif N.
Shakespeare, Callum J.
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| Data: |
2015-09
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| Ano: |
2015
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| Palavras-chave: |
Circulation/ Dynamics
Frontogenesis/frontolysis
Fronts
Ocean dynamics
Atm/Ocean Structure/ Phenomena
Water masses
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| Resumo: |
A simple analytical model is used to elucidate a potential mechanism for steady-state mode water formation at a thermohaline front that involves frontogenesis, submesoscale lateral mixing, and cabbeling. This mechanism is motivated in part by recent observations of an extremely sharp, density-compensated front at the North Wall of the Gulf Stream. Here, the intergyre, along-isopycnal, salinity-temperature difference is compressed into a span of a few kilometers, making the flow susceptible to cabbeling. The sharpness of the front is caused by frontogenetic strain, which is presumably balanced by submesoscale lateral mixing processes. The balance is studied with the simple model, and a scaling is derived for the amount of water mass transformation resulting from the ensuing cabbeling. The transformation scales with the strain rate, equilibrated width of the front, and the square of the isopycnal temperature contrast across the front. At the major ocean fronts where mode waters are found, this isopycnal temperature contrast decreases with increasing density near the isopycnal layers where mode waters reside. This implies that cabbeling should result in a convergent diapycnal mass flux into mode water density classes. The scaling for the transformation suggests that at these fronts the process could generate 0.01-1 Sverdrups (Sv; 1 Sv equivalent to 10(6) m(3) s(-1)) of mode water. These formation rates, while smaller than mode water formation by air-sea fluxes, should be independent of season and thus could fill select isopycnal layers continuously and play an important role in the dynamics of mode waters on interannual time scales.
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| Tipo: |
Text
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| Idioma: |
Inglês
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| Identificador: |
https://archimer.ifremer.fr/doc/00351/46243/46107.pdf
DOI:10.1175/JPO-D-15-0007.1
https://archimer.ifremer.fr/doc/00351/46243/
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| Editor: |
Amer Meteorological Soc
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| Formato: |
application/pdf
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| Fonte: |
Journal Of Physical Oceanography (0022-3670) (Amer Meteorological Soc), 2015-09 , Vol. 45 , N. 9 , P. 2444-2456
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| Direitos: |
2015 American Meteorological Society
info:eu-repo/semantics/openAccess
restricted use
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