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Titel |
Short-term impacts of enhanced Greenland freshwater fluxes in an eddy-permitting ocean model |
VerfasserIn |
R. Marsh, D. Desbruyères, J. L. Bamber, B. A. Cuevas, A. C. Coward, Y. Aksenov |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1812-0784
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Digitales Dokument |
URL |
Erschienen |
In: Ocean Science ; 6, no. 3 ; Nr. 6, no. 3 (2010-07-23), S.749-760 |
Datensatznummer |
250003583
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Publikation (Nr.) |
copernicus.org/os-6-749-2010.pdf |
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Zusammenfassung |
In a sensitivity experiment, an eddy-permitting ocean general circulation
model is forced with realistic freshwater fluxes from the Greenland Ice
Sheet, averaged for the period 1991–2000. The fluxes are obtained with a
mass balance model for the ice sheet, forced with the ERA-40 reanalysis
dataset. The freshwater flux is distributed around Greenland as an
additional term in prescribed runoff, representing seasonal melting of the
ice sheet and a fixed year-round iceberg calving flux, for 8.5 model years.
By adding Greenland freshwater fluxes with realistic geographical
distribution and seasonality, the experiment is designed to investigate the
oceanic response to a sudden and spatially/temporally uniform amplification
of ice sheet melting and discharge, rather than localized or gradual changes
in freshwater flux. The impacts on regional hydrography and circulation are
investigated by comparing the sensitivity experiment to a control
experiment, without additional fluxes. By the end of the sensitivity
experiment, the majority of additional fresh water has accumulated in Baffin
Bay, and only a small fraction has reached the interior of the Labrador Sea,
where winter mixed layer depth is sensitive to small changes in salinity. As
a consequence, the impact on large-scale circulation is very slight. An
indirect impact of strong freshening off the west coast of Greenland is a
small anti-cyclonic component to the circulation around Greenland, which
opposes the wind-driven cyclonic circulation and reduces net southward flow
through the Canadian Archipelago by ~10%. Implications for the
post-2000 acceleration of Greenland mass loss are discussed. |
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