Articles | Volume 26, issue 12
https://doi.org/10.5194/angeo-26-4075-2008
https://doi.org/10.5194/angeo-26-4075-2008
12 Dec 2008
 | 12 Dec 2008

Is the decadal variability in the tropical Atlantic a precursor to the NAO?

I. Wainer, J. Servain, and G. Clauzet

Abstract. In the past two decades climate research in the tropical Atlantic with respect to the inter-hemispheric gradient of sea surface temperature (SST) emphasized the predominance of decadal-scale variability. Our results show that this mode of variability is prevalent only for part of the last 130-years record (the 1880s, the 1920s and, especially, the 1970s). There is a lag of a few months between the decadal variations of the inter-hemispheric gradient of SST and the decadal variability of the North Atlantic Oscillation (NAO). This seems to indicate that the 10-year variability first develops in the tropics and then propagates polewards. The inter-hemispheric gradient of SST mode should be thought as episodic and not as a periodic oscillation.

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