Relations entre la pluviométrie au Sahel central et divers indices climatiques sur l’Atlantique: exemple de la station de Maïné-Soroa

Bastien Dieppois, Alain Durand, Matthieu Fournier, Nicolas Massei, B. Hassane

Research output: Chapter in Book/Report/Conference proceedingConference proceeding

Abstract

Pluviometry variability at Maïné-Soroa station (SE Niger) shows correlation at 0.75 with the Central Sahel pluviometric index established by Lebel and Ali (2009) from 1950 to 2005. Three mains periods were indetified : wet (1950-1967), arid (1968-1999) and semi-arid (1988/89-2005). Continuous Wavelet Transform was used to evaluate forced (climatic) variability of pluviometric signal. An intensification of the 2-4 years and 5-8 years frequency bands is observed during wet and semiarid periods. Conversely, these bands become weaken and the 12-18 years band appears stronger during arid period. Moreover, Wavelet coherence and Phase are used to identify forcing climate indices. During the wet period, climate indices (NAO and Tropical North Atlantic SST) are coherent and in phase with pluviometry, while during the arid period, climate indices (NAO, Tropical North and South Atlantic SSTs) are coherent with pluviometry but out of phases.
Discover the world's research
Original languageFrench
Title of host publicationRisques et Changement climatiques (Dubreuil et al. [eds.]), 23e Colloque de l’Association International de Climatologie, Rennes, France
Volume23
EditionAssociation International de Climatologie
Publication statusPublished - 2010

Cite this