%0 Conference Proceedings
%9 ACTI : Communications avec actes dans un congrès international
%A Carré, M.
%A Azzoug, M.
%A Camara, A.
%A Cheddadi, R.
%A Gaye, A.
%A Janicot, Serge
%A Khodri, Myriam
%A Lazar, Alban
%A Lazareth, Claire
%A Mignot, Juliette
%A Wade, M.
%T Sahel rainfall negatively linked to global temperature during the past 1600 years [résumé de poster]
%S PAGES Zaragoza 2017 : global challenges for our common future : a paleoscience perspective : abstract book
%C Berne
%D 2017
%L fdi:010071197
%G ENG
%I PAGES
%K SAHEL ; ZONE SAHELIENNE
%P 195
%U https://www.documentation.ird.fr/hor/fdi:010071197
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers17-11/010071197.pdf
%W Horizon (IRD)
%X As climate model uncertainties remain very large for future rainfall in the Sahel, a multi-centennial perspective is required to assess the relationship between global warming and the Sahel hydroclimate. We present here a new record of hydrologic conditions over the past 1600 years in Senegal, obtained from stable oxygen isotope analyses (δ18O) in archaeological shell middens in the Saloum Delta. During the preindustrial period, the Sahel was relatively humid, particularly from AD 1500 to AD 1800, during the coolest period of the last two millennia, referred to as the Little Ice Age. A strong negative link is observed at the centennial scale between global temperature and humidity in the Sahel, in direct contrast with the relationship observed elsewhere in the northern tropics, which shows that the processes linking the Intertropical Convergence Zone (ITCZ) and the West African Monsoon (WAM) are more complex than previously thought. The relationships between changes in the annual mean state and seasonal to interannual variability are explored using monthly resolved shell isotope records. In the context of the past 1600 years, the Western Sahel appears to be experiencing unprecedented drought conditions, resulting from a rapid aridification since AD 1800 that points to local and global anthropogenic forcings. This new long-term perspective suggests that under future global warming the potential for severe Sahel droughts may increase significantly.
%B Past Global Changes Open Science Meeting (PAGES OSM) : Global Challenges for our Common Future : a Paleoscience Perspective
%8 2017/05/09-13
%$ 021CLIMAT01