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| Titel |
Intraseasonal variability of the ocean - atmosphere coupling in the eastern atlantique equatorial upwelling |
| VerfasserIn |
Gaelle de Coëtlogon, Alban Lazar, Serge Janicot |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250057556
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| Zusammenfassung |
| Statistical analyses of the satellite TMI sea-surface temperature (SST) and QuikSCAT surface winds allows to investigate the intraseasonal variability of air – sea interactions in the equatorial Atlantic upwelling. There, a 15 days SST signal in boreal spring-summer is detected with 5-day lag wind forcing and 3-day lag strong negative SST feedback. It is connected to large-scale fluctuations of the St Helena anticyclone.
Within about 5◦ S and 5◦ N, two retroactions between SST and
surface wind appear to dominate near-surface atmosphere conditions. When the wind leads the SST, stronger monsoonal
winds north of 2◦ N are partly sustained by the developing SST anomaly. When the SST leads the wind, a reversal of anomalous winds is observed mainly south of 2◦ N, closing a
negative feedback loop with a biweekly periodicity. Further investigation with an ocean model emphasizes the
role of the meridional Ekman current in shaping these intraseasonal SST signals. |
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