Open AccessAn Idealized Two-Dimensional Framework to Study the West African Monsoon. Part I: Validation and Key Controlling Factors
Author(s) -
Philippe Peyrillé,
Jean-Philippe Lafore,
JeanLuc Redelsperger
Publication year - 2007
Publication title -
journal of the atmospheric sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.853
H-Index - 173
eISSN - 1520-0469
pISSN - 0022-4928
DOI - 10.1175/jas3919.1
Subject(s) - climatology , monsoon , zonal and meridional , eddy , environmental science , mediterranean climate , dryness , sea surface temperature , atmospheric sciences , momentum (technical analysis) , west coast , albedo (alchemy) , geology , oceanography , meteorology , geography , turbulence , medicine , art , surgery , archaeology , finance , performance art , economics , art history
An idealized vertical–meridional zonally symmetric model is developed in order to recover a July typical monsoon regime over West Africa in response to surface conditions. The model includes a parameterization to account for heat and momentum fluxes associated with eddies. The sensitivity of the simulated West African monsoon equilibrium regime to some major processes is explored. It allows confirmation of the important role played by the sun’s latitudinal position, the aerosols, the albedo, and the SST’s magnitude in the Gulf of Guinea and in the Mediterranean Sea. The important role of aerosols in warming the Saharan lower layers and their effect on the whole monsoon is underlined. Model results also stress the importance of the Mediterranean Sea, which is needed to obtain the extreme dryness of the Sahara. The use of this idealized model is finally discussed for studying the scale interactions and coupling involved in the West African monsoon as explored in a companion paper.