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| Titel |
Atlantic meridional ocean heat transport at 26° N: impact on subtropical ocean heat content variability |
| VerfasserIn |
M. Sonnewald, J. J.-M. Hirschi, R. Marsh, E. L. McDonagh, B. A. King |
| 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 ; 9, no. 6 ; Nr. 9, no. 6 (2013-12-05), S.1057-1069 |
| Datensatznummer |
250085281
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| Publikation (Nr.) |
 copernicus.org/os-9-1057-2013.pdf |
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| Zusammenfassung |
| Local climate is significantly affected by changes in the oceanic heat
content on a range of timescales. This variability is driven by heat fluxes
from both the atmosphere and the ocean. In the Atlantic the meridional
overturning circulation is the main contributor to the oceanic meridional
heat transport for latitudes south of about 50° N. The RAPID
project has been successfully monitoring the Atlantic meridional overturning
at 26° N since 2004. This study demonstrates how these data can be
used to estimate the variability of the basin-wide ocean heat content in the
upper 800 m between 26° and 36° N. Traditionally the atmosphere
is seen to dominate the ocean heat content variability. However, previous
studies have looked at smaller areas in the Gulf Stream region, finding that
the ocean dominates deseasoned fluctuations of ocean heat content, while
studies of the whole North Atlantic region suggest that the atmosphere may be
dominant. In our study we use a box model to investigate fluctuations of the
ocean heat content in the subtropical North Atlantic between 26° and
36° N. The box model approach is validated using 19 yr of high-resolution
general circulation model (GCM) data. We find that in both the GCM- and RAPID-based data the
ocean heat transport dominates the deseasoned heat content variability, while
the atmosphere's impact on the ocean heat content evolution stabilizes after
6 months. We demonstrate that the utility of the RAPID data goes beyond
monitoring the overturning circulation at 26° N, and that it can be
used to better understand the causes of ocean heat content variability in the
North Atlantic. We illustrate this for a recent decrease in ocean heat
content which was observed in the North Atlantic in 2009 and 2010. Our
results suggest that most of this ocean heat content reduction can be
explained by a reduction of the meridional ocean heat transport during this
period. |
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