An Idealized Two-Dimensional Framework to Study the West African Monsoon. Part I: Validation and Key Controlling Factors
Open Access
- 1 August 2007
- journal article
- Published by American Meteorological Society in Journal of the Atmospheric Sciences
- Vol. 64 (8) , 2765-2782
Abstract
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.Keywords
This publication has 78 references indexed in Scilit:
- Monsoon Dynamics with Interactive Forcing. Part II: Impact of Eddies and Asymmetric GeometriesJournal of the Atmospheric Sciences, 2007
- Role of the Hoggar massif in the West African monsoon onsetGeophysical Research Letters, 2005
- Numerical study of a Sahelian synoptic weather system: Initiation and mature stages of convection and its interactions with the large‐scale dynamicsQuarterly Journal of the Royal Meteorological Society, 2002
- Easterly Waves over Africa. Part II: Observed and Modeled Contrasts between Wet and Dry YearsMonthly Weather Review, 2002
- The role of Bright Desert Regions in shaping North African climateGeophysical Research Letters, 2001
- High-Resolution Non-Hydrostatic Simulations of Flash-Flood Episodes with Grid-Nesting and Ice-Phase ParameterizationMeteorology and Atmospheric Physics, 2000
- Simulation of an abrupt change in Saharan vegetation in the Mid‐HoloceneGeophysical Research Letters, 1999
- Maintenance of the African easterly jetQuarterly Journal of the Royal Meteorological Society, 1999
- Contribution of different aerosol species to the global aerosol extinction optical thickness: Estimates from model resultsJournal of Geophysical Research: Atmospheres, 1997
- The Role of Orography in Determining the Sahelian ClimateInternational Journal of Climatology, 1997