Volumes and Issues  Contents of Issue 9  
Ann. Geophys., 26, 2569-2595, 2008
www.ann-geophys.net/26/2569/2008/
doi:10.5194/angeo-26-2569-2008
© European Geosciences Union 2008


Large-scale overview of the summer monsoon over West Africa during the AMMA field experiment in 2006

S. Janicot1, C. D. Thorncroft2, A. Ali3, N. Asencio4, G. Berry2, O. Bock5, B. Bourles6, G. Caniaux4, F. Chauvin4, A. Deme7, L. Kergoat8, J.-P. Lafore4, C. Lavaysse5, T. Lebel3, B. Marticorena9, F. Mounier1, P. Nedelec10, J.-L. Redelsperger4, F. Ravegnani11, C. E. Reeves12, R. Roca7, P. de Rosnay8, H. Schlager13, B. Sultan1, M. Tomasini4, A. Ulanovsky14, and ACMAD forecasters team15
1Institut de Recherches pour le Développement, Laboratoire d'Océanographie et du Climat: Expérimentation et Analyses Numériques, Paris, France
2University of Albany, Department of Earth and Atmospheric Sciences, Albany, NY, USA
3Institut de Recherches pour le Développement, Laboratoire d'étude des Transferts en Hydrologie et Environnement, Grenoble, France
4Meteo-France, Centre National de la Recherche Météorologique, Toulouse, France
5Université Pierre et Marie Curie, Service d'Aéronomie, Paris, France
6Inst. de Recherches pour le Développement, Lab. d'Etudes en Géophysique et Océanographie Spatiale, Brest, France
7Centre National de la Recherche Scientifique, Laboratoire de Météorologie Dynamique, Paris, France
8Centre National de la Recherche Scientifique, Centre d'Etudes Spatiale de la Biosphère, Toulouse, France
9Centre National de la Recherche Scientifique, Laboratoire Inter-universitaire des Systèmes Atmosphériques, Créteil, France
10Centre National de la Recherche Scientifique, Laboratoire d'Aérologie, Toulouse, France
11Istituto di Scienze dell'Atmosfera e del Clima – Consiglio Nazionale di Ricerca Italiano, Bologna, Italy
12University of East Anglia, School of Environmental Sciences, Norwich, UK
13Deutsches Zentrum fuer Luftund Raumfahrt, Institut fuer Physik der Atmosphaere, Oberpfaffenhofen-Wessling, Germany
14Central Aerological Observatory, Moscow, Russia
15African Centre of Meteorological Application for Development, Niamey, Niger

 Abstract. The AMMA (African Monsoon Multidisciplinary Analysis) program is dedicated to providing a better understanding of the West African monsoon and its influence on the physical, chemical and biological environment regionally and globally, as well as relating variability of this monsoon system to issues of health, water resources, food security and demography for West African nations. Within this framework, an intensive field campaign took place during the summer of 2006 to better document specific processes and weather systems at various key stages of this monsoon season. This campaign was embedded within a longer observation period that documented the annual cycle of surface and atmospheric conditions between 2005 and 2007. The present paper provides a large and regional scale overview of the 2006 summer monsoon season, that includes consideration of of the convective activity, mean atmospheric circulation and synoptic/intraseasonal weather systems, oceanic and land surface conditions, continental hydrology, dust concentration and ozone distribution. The 2006 African summer monsoon was a near-normal rainy season except for a large-scale rainfall excess north of 15° N. This monsoon season was also characterized by a 10-day delayed onset compared to climatology, with convection becoming developed only after 10 July. This onset delay impacted the continental hydrology, soil moisture and vegetation dynamics as well as dust emission. More details of some less-well-known atmospheric features in the African monsoon at intraseasonal and synoptic scales are provided in order to promote future research in these areas.

 Full Article (PDF, 21537 KB)   

Citation: Janicot, S., Thorncroft, C. D., Ali, A., Asencio, N., Berry, G., Bock, O., Bourles, B., Caniaux, G., Chauvin, F., Deme, A., Kergoat, L., Lafore, J.-P., Lavaysse, C., Lebel, T., Marticorena, B., Mounier, F., Nedelec, P., Redelsperger, J.-L., Ravegnani, F., Reeves, C. E., Roca, R., de Rosnay, P., Schlager, H., Sultan, B., Tomasini, M., Ulanovsky, A., and ACMAD forecasters team: Large-scale overview of the summer monsoon over West Africa during the AMMA field experiment in 2006, Ann. Geophys., 26, 2569-2595, doi:10.5194/angeo-26-2569-2008, 2008.   Bibtex   EndNote   Reference Manager    XML
 

Recent Papers