Open AccessSahel megadroughts triggered by glacial slowdowns of Atlantic meridional overturning
Author(s) -
Mulitza Stefan,
Prange Matthias,
Stuut JanBerend,
Zabel Matthias,
von Dobeneck Tilo,
Itambi Achakie C.,
Nizou Jean,
Schulz Michael,
Wefer Gerold
Publication year - 2008
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/2008pa001637
Subject(s) - geology , stadial , climatology , oceanography , glacial period , trough (economics) , last glacial maximum , monsoon , north atlantic deep water , aeolian processes , arid , thermohaline circulation , shutdown of thermohaline circulation , holocene , geomorphology , paleontology , economics , macroeconomics
The influence of the large‐scale ocean circulation on Sahel rainfall is elusive because of the shortness of the observational record. We reconstructed the history of eolian and fluvial sedimentation on the continental slope off Senegal during the past 57,000 years. Our data show that abrupt onsets of arid conditions in the West African Sahel were linked to cold North Atlantic sea surface temperatures during times of reduced meridional overturning circulation associated with Heinrich Stadials. Climate modeling suggests that this drying is induced by a southward shift of the West African monsoon trough in conjunction with an intensification and southward expansion of the midtropospheric African Easterly Jet.