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| Titel |
Sensitivity of response of Southern Ocean Dynamics to wind patterns and intensity |
| VerfasserIn |
Carolina O. Dufour, Julien Le Sommer, Marion Gehlen, James C. Orr, Pierre Mathiot, Bernard Barnier |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034993
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| Zusammenfassung |
| The response of Southern Ocean dynamics and biogeochemistry, particularly air-sea CO2
fluxes, to the current climate trend in the SAM is under debate. At the crux of that
debate is the role played by mesoscale eddies in moderating air-sea CO2 fluxes.
Eddies are a key feature of Southern Ocean dynamics, but they are poorly resolved in
coarse-resolution ocean models that have been used to diagnose changes in these fluxes.
Moreover, there have been few related sensitivity experiments regarding the trend
in the SAM. Here, we examine the sensitivity of Southern Ocean circulation and
tracer distributions to perturbed winds and mesoscale eddies in a coupled ocean-sea
ice model (NEMO) forced by atmospheric reanalysis. Its regional configuration
includes all ocean south of 30°S, and it is run at both coarse (1/2°) and eddying
resolutions (1/4° and 1/8°). A series of simulations over recent decades were made
where wind patterns and intensity were modified. Our focus here is on the simulated
ACC transport, overturning circulation, and tracer distributions. Resolving eddies
substantially modifies the Southern Ocean response to winds, and that response strongly
depends on the spatial structure of wind anomalies. Our results suggest that (i)
coarse-resolution models do not accurately capture the response of the Southern
Ocean dynamics and biogeochemistry to changes in atmospheric forcing and (ii) the
spatial structure of the SAM is critical in the Southern Ocean response to the SAM. |
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