Risi C. auteur aut IRD Bony S. auteur aut IRD Vimeux Francoise auteur aut IRD Descroix Luc auteur aut IRD Ibrahim B. auteur aut IRD Lebreton E. auteur aut IRD Mamadou I. auteur aut IRD Sultan Benjamin auteur aut IRD text journalArticle eng text/pdf reformatted digital access The stable isotopic composition of the tropical precipitation constitutes a useful tool for paleoclimate reconstructions and to better constrain the water cycle. To better understand what controls the isotopic composition of tropical precipitation, we analyze the delta O-18 and deuterium-excess of the precipitation of individual events collected in the Niamey area (Niger) during the monsoon season, as part of the 2006 AMMA field campaign. During the monsoon onset, the abrupt increase of convective activity over the Sahel is associated with an abrupt change in the isotopic composition. Before the onset, when convective activity is scarce, the rain composition records the intensity and the organization of individual convective systems. After the onset, on the contrary, it records a regional-scale intra-seasonal variability over the Sahel, by integrating convective activity both spatially and temporally over the previous days. Citation: Risi, C., S. Bony, F. Vimeux, L. Descroix, B. Ibrahim, E. Lebreton, I. Mamadou, and B. Sultan (2008), What controls the isotopic composition of the African monsoon precipitation? Insights from event-based precipitation collected during the 2006 AMMA field campaign, Geophys. Res. Lett., 35, L24808, doi: 10.1029/2008GL035920. specialized 021 35 24 L24808 2008 0094-8276 https://www.documentation.ird.fr/hor/fdi:010074996 10.1029/2008gl035920 0094-8276 [F B010074996] https://www.documentation.ird.fr/hor/fdi:010074996 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers19-01/010074996.pdf IRD - Base Horizon / Pleins textes 2009-02-06 2025-01-28 fdi:010074996 fre