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Role of the Hoggar massif in the West African monsoon onset
Author(s) -
Drobinski Philippe,
Sultan Benjamin,
Janicot Serge
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl020710
Subject(s) - orography , monsoon , massif , geology , climatology , anticyclone , trough (economics) , precipitation , geochemistry , geography , meteorology , economics , macroeconomics
It has been observed that the West African monsoon onset is concomitant with the enhancement of the Saharan heat low. We show through a combined diagnostic and linear modeling study a possible interaction between northern Africa orography and the deepening of the Saharan heat low at the time of the monsoon onset. The amplification of an anticyclonic circulation above and north of the Hoggar massif leads to an increase and a southeasterly‐northeasterly rotation of the wind ahead of the Hoggar which contribute to an increased leeward‐trough effect enhancing the Saharan heat low. The Atlas does not play any role during the monsoon onset but contributes to the mean climatological location of the Saharan heat low.