Intraseasonal variability of the West African monsoon Monsoon Multidisciplinary Analysis (AMMA) : an integrated project for understanding of the West African climate system and its human dimension /Janicot, Serge Caniaux, G. Chauvin, F. de Coëtlogon, G. Fontaine, B. Hall, N. Kiladis, G. Lafore, J. P. Lavaysse, C. Lavender, S. L. Leroux, S. Marteau, R. Mounier, F. Philippon, N. Roehrig, R. /Sultan, Benjamin Taylor, C. M. West African monsoon intraseasonal variability monsoon onset predictability crop yield The intraseasonal time scale is critical in West Africa where resources are highly rainfall dependent. Three main modes of variability have been identified, two with a mean periodicity of 15 days and one with a mean periodicity around 40 days. These modes have a regional scale and can strongly influence precipitation and convective activity. They are mainly controlled by atmospheric dynamics and land-surface interactions. They can also modulate the very specific phase of the African summer monsoon onset. A better knowledge of the mechanisms controlling this scale is necessary to improve its predictability. Copyright. 2011 text https://www.documentation.ird.fr/hor/fdi:010053181 fdi:010053181 Janicot Serge, Caniaux G., Chauvin F., de Coëtlogon G., Fontaine B., Hall N., Kiladis G., Lafore J. P., Lavaysse C., Lavender S. L., Leroux S., Marteau R., Mounier F., Philippon N., Roehrig R., Sultan Benjamin, Taylor C. M.. Intraseasonal variability of the West African monsoon. In : . Monsoon Multidisciplinary Analysis (AMMA) : an integrated project for understanding of the West African climate system and its human dimension 2011, 12 (1), 58-66 EN