Role of the Gulf of Guinea in the inter-annual variability of the West African monsoon: what do we learn from CMIP3 coupled simulations?

2009 ◽  
Vol 30 (12) ◽  
pp. 1843-1856 ◽  
Author(s):  
Mathieu Joly ◽  
Aurore Voldoire
Keyword(s):  
West African Monsoon ◽  
West African ◽  
Gulf Of Guinea ◽  
The West ◽  
African Monsoon ◽  
Annual Variability

scholarly journals Coupled Model Simulations of the West African Monsoon System: Twentieth- and Twenty-First-Century Simulations

2006 ◽  
Vol 19 (15) ◽  
pp. 3681-3703 ◽  
Author(s):  
Kerry H. Cook ◽  
Edward K. Vizy
Keyword(s):  
Twentieth Century ◽  
West African Monsoon ◽  
West African ◽  
First Century ◽  
Gulf Of Guinea ◽  
Physical Processes ◽  
The West ◽  
African Monsoon ◽  
The Third ◽  
Twenty First Century

Abstract The ability of coupled GCMs to correctly simulate the climatology and a prominent mode of variability of the West African monsoon is evaluated, and the results are used to make informed decisions about which models may be producing more reliable projections of future climate in this region. The integrations were made available by the Program for Climate Model Diagnosis and Intercomparison for the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. The evaluation emphasizes the circulation characteristics that support the precipitation climatology, and the physical processes of a “rainfall dipole” variability mode that is often associated with dry conditions in the Sahel when SSTs in the Gulf of Guinea are anomalously warm. Based on the quality of their twentieth-century simulations over West Africa in summer, three GCMs are chosen for analysis of the twenty-first century integrations under various assumptions about future greenhouse gas increases. Each of these models behaves differently in the twenty-first-century simulations. One model simulates severe drying across the Sahel in the later part of the twenty-first century, while another projects quite wet conditions throughout the twenty-first century. In the third model, warming in the Gulf of Guinea leads to more modest drying in the Sahel due to a doubling of the number of anomalously dry years by the end of the century. An evaluation of the physical processes that cause these climate changes, in the context of the understanding about how the system works in the twentieth century, suggests that the third model provides the most reasonable projection of the twenty-first-century climate.

scholarly journals A seamless assessment of the role of convection in the water cycle of the West African Monsoon

2014 ◽  
Vol 119 (6) ◽  
pp. 2890-2912 ◽  
Author(s):  
C. E. Birch ◽  
D. J. Parker ◽  
J. H. Marsham ◽  
D. Copsey ◽  
L. Garcia-Carreras
Keyword(s):  
Water Cycle ◽  
West African Monsoon ◽  
West African ◽  
The West ◽  
African Monsoon

scholarly journals Decadal and multi-year predictability of the West African monsoon and the role of dynamical downscaling

2017 ◽  
Vol 26 (4) ◽  
pp. 363-377 ◽  
Author(s):  
Heiko Paeth ◽  
Andreas Paxian ◽  
Dmitry V. Sein ◽  
Daniela Jacob ◽  
Hans-Jürgen Panitz ◽  
...  
Keyword(s):  
Dynamical Downscaling ◽  
West African Monsoon ◽  
West African ◽  
The West ◽  
African Monsoon

The role of the Indian monsoon onset in the West African monsoon onset: observations and AGCM nudged simulations

2011 ◽  
Vol 38 (5-6) ◽  
pp. 965-983 ◽  
Author(s):  
Emmanouil Flaounas ◽  
Serge Janicot ◽  
Sophie Bastin ◽  
Rémy Roca ◽  
Elsa Mohino
Keyword(s):  
Indian Monsoon ◽  
West African Monsoon ◽  
Monsoon Onset ◽  
West African ◽  
The West ◽  
African Monsoon

scholarly journals Development of a Coupled Regional Model and Its Application to the Study of Interactions between the West African Monsoon and the Eastern Tropical Atlantic Ocean

2009 ◽  
Vol 22 (10) ◽  
pp. 2591-2604 ◽  
Author(s):  
Samson M. Hagos ◽  
Kerry H. Cook
Keyword(s):  
West African Monsoon ◽  
Coupled Model ◽  
West African ◽  
Monsoon Circulation ◽  
Tropical Atlantic ◽  
Gulf Of Guinea ◽  
The West ◽  
African Monsoon ◽  
Wind Speeds ◽  
Westerly Flow

Abstract A regional ocean–atmosphere coupled model is developed for climate variability and change studies. The model allows dynamic and thermodynamic interactions between the atmospheric boundary layer and an ocean mixed layer with spatially and seasonally varying depth prescribed from observations. The model reproduces the West African monsoon circulation as well as aspects of observed seasonal SST variations in the tropical Atlantic. The model is used to identify various mechanisms that couple the West African monsoon circulation with eastern Atlantic SSTs. By reducing wind speeds and suppressing evaporation, the northward migration of the ITCZ off the west coast of Africa contributes to the modeled spring SST increases. During this period, the westerly monsoon flow is expanded farther westward and moisture transport on to the continent is enhanced. Near the end of the summer, upwelling associated with this enhanced westerly flow as well as the solar cycle lead to the seasonal cooling of the SSTs. Over the Gulf of Guinea, the acceleration of the southerly West African monsoon surface winds contributes to cooling of the Gulf of Guinea between April and July by increasing the entrainment of cool underlying water and enhancing evaporation.

scholarly journals The role of moist convection in the West African monsoon system: Insights from continental-scale convection-permitting simulations

2013 ◽  
Vol 40 (9) ◽  
pp. 1843-1849 ◽  
Author(s):  
John H. Marsham ◽  
Nick S. Dixon ◽  
Luis Garcia-Carreras ◽  
Grenville M. S. Lister ◽  
Douglas J. Parker ◽  
...  
Keyword(s):  
West African Monsoon ◽  
West African ◽  
Moist Convection ◽  
The West ◽  
African Monsoon ◽  
Continental Scale ◽  
Monsoon System

scholarly journals An Idealized Two-Dimensional Framework to Study the West African Monsoon. Part I: Validation and Key Controlling Factors

2007 ◽  
Vol 64 (8) ◽  
pp. 2765-2782 ◽  
Author(s):  
Philippe Peyrillé ◽  
Jean-Philippe Lafore ◽  
Jean-Luc Redelsperger
Keyword(s):  
Mediterranean Sea ◽  
West African Monsoon ◽  
Companion Paper ◽  
West African ◽  
Symmetric Model ◽  
The West ◽  
African Monsoon ◽  
Latitudinal Position ◽  
The Mediterranean

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.

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