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| Titel |
Seasonal to interannual variability in density around the Canary Islands and their influence on the Atlantic Meridional Overturning Circulation at 26N |
| VerfasserIn |
Aurelie Duchez, Eleanor Frajka-Williams, Natalia Castro, Joel Hirschi, Andrew Coward |
| 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 |
250091343
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| Publikation (Nr.) |
 EGU/EGU2014-5631.pdf |
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| Zusammenfassung |
| The meridional interior flow obtained from the RAPID array is determined by horizontal
density fluctuations at the eastern and western boundary of 26N. The physical causes of these
density variations are responsible for fluctuations in the Atlantic Meridional Overturning
Circulation (AMOC) and through it, the meridional heat transport of the Atlantic. In this
modelling study, a high resolution ocean model is used to investigate the source and origin of
the AMOC variability associated with the density fluctuations at the eastern boundary. The
AMOC in the model is in good
agreement with the RAPID observations and appears to adequately represent the smaller
scale features of variability around the Canary Islands.
In this study, we identify a robust relationship between the density structure south of the
Canary Islands, the local wind stress curl and the AMOC using an empirical orthogonal
functions analysis, wavelet transform and wavelet coherence. We find that the deep
density fluctuations at the eastern boundary of 26N arise from the pumping effect
of the spatial pattern of wind stress curl south of the islands. These deep density
fluctuations drive the AMOC both on seasonal and interannual timescales, through their
influence on the basinwide tilt of the thermocline. At seasonal timescales, the density
fluctuations south of the islands are driven by the WSC and directly influence the
AMOC. At interannual timescales, a significant coherence is found between the
density fluctuation and the southward UMO transport although the origin of these
density fluctuations is not explained by the direct pumping caused by the WSC. |
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