Contribution of the triple oxygen isotope composition of precipitation to the identification of surface-atmosphere interactions in the sub-humid part of West Africa

Christine Vallet-Coulomb (1) , Anne Alexandre (1) , Christophe Peugeot (2) , Abdoukarim Alassane (3) , Vinel Gbewezoun (3) , Martine Couapel (1) , Clément Outrequin (1) , Théodore Ouani (4) , Simon Afouda (4)

1 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
2 HSM - Hydrosciences Montpellier
3 UAC - Université d’Abomey-Calavi = University of Abomey Calavi
4 IRD - Institut de Recherche pour le Développement [Cotonou, Bénin]

This study aims at evaluating the information carried by the 17O-excess composition of precipitation in the sub-humid part of West Africa. Located at the southern border of the Sahelian band, the so-called “Sudanian Climatic Zone”, characterized by annual precipitation of 1200-1400mm, plays a crucial role in providing water to large African watersheds such as the Niger river’s one, and the Lake Chad catchment. Surface-atmosphere interactions were shown to influence convective processes in the semi-arid Sahelian band, with positive feedbacks between vegetation land cover and rainfall. Less focus has been put on the more humid Sudanian Zone, although surface-atmosphere interactions may have an important influence on the control of rainfall variations, and therefore on water resource availability in these watersheds.

Domaines: Sciences de la Terre

Christine Vallet-Coulomb, Anne Alexandre, Christophe Peugeot, Abdoukarim Alassane, Vinel Gbewezoun, et al.. Contribution of the triple oxygen isotope composition of precipitation to the identification of surface-atmosphere interactions in the sub-humid part of West Africa. EGU General Assembly 2020, May 2020, Vienne (virtuel), Austria. ⟨10.5194/egusphere-egu2020-13543⟩. ⟨hal-03552174⟩