Science et changements planétaires / Sécheresse


Squall lines and rainfall over West Africa: Daily variations Volume 15, issue 3, JUILLET-AOÛT-SEPTEMBRE 2004


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Laboratoire de physique de l’atmosphère Siméon Fongang (LPASF), École supérieure polytechnique Université Cheikh Anta Diop (UCAD), Dakar, Laboratoire de météorologie dynamique Institut Pierre-Simon Laplace (IPSL), École polytechnique 91128 Palaiseau cedex

Using eight daily slots provided by the Meteosat IR channel, one follows 153 squall lines (SLs) over Western Africa during the months of July, August and September of the 1986 and 1987. The SLs rainfall is computed using daily observations of 800 raingauges. Thanks to the SLs’ rapid movement, daily area and rainfall variations are described. Areas are at a minimum around 15 UTC whilst rainfall is at a maximum around 18 and 21 UTC.