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| Titel |
Heat fluxes across the Antarctic Circumpolar Current |
| VerfasserIn |
Ramiro Ferrari, Christine Provost, Young Hyang Park, Nathalie Sennéchael, Gilles Garric, Romain Bourdallé-Badie |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087646
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| Publikation (Nr.) |
 EGU/EGU2014-1705.pdf |
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| Zusammenfassung |
| Determining the processes responsible for the Southern Ocean heat balance is fundamental
to our understanding of the weather and climate systems. Therefore, in the last
decades, various studies aimed at analyzing the major mechanisms of the oceanic
poleward heat flux in this region. Previous works stipulated that the cross-stream heat
flux due to the mesoscale transient eddies was responsible for the total meridional
heat transport across the Antarctic Circumpolar Current (ACC). Several numerical
modelling and current meters data studies have recently challenged this idea. These
showed that the heat flux due to the mean flow in the southern part of the Antarctic
Circumpolar Current could be larger than the eddy heat flux contribution by two orders of
magnitude.
Eddy heat flux and heat flux by the mean flow distributions of were examined in Drake
Passage using in situ measurements collected during the DRAKE 2006-9 project (from
January 2006 to March 2009), available observations from the historical DRAKE 79
experiment and high resolution model outputs (ORCA 12, MERCATOR).
The Drake Passage estimations provided a limited view of heat transport in
the Southern Ocean. The small spatial scales shown by the model derived heat
flux by the mean flow indicate that circumpolar extrapolations from a single point
observation are perilous. The importance of the heat flux due by the mean flow
should be further investigated using other in situ observations and numerical model
outputs.
Similar situation has been observed, with important implication for heat flux due to the
mean flow, in other topographically constricted regions with strong flow across prominent
submarine ridges (choke points). We have estimated the heat flux due to the mean flow
revisiting other ACC mooring sites where in situ time series are available, e.g. south of
Australia (Tasmania) (Phillips and Rintoul, 2000), southeast of New Zealand (Campbell
Plateau) (Bryden and Heath, 1985).
Heat fluxes due to the mean flow at those choke points were compared to model outputs
and provided new circumpolar estimates indicating that the choke points are a potential
overwhelming contribution for the heat flux needed to balance heat lost to the atmosphere in
the Southern Ocean. |
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