Abstract:
A detailed reconstruction of West African monsoon hydrology over the
past 155,000 years suggests a close linkage to northern high-latitude
climate oscillations. Ba/Ca ratio and oxygen isotope composition of
planktonic foraminifera in a marine sediment core from the Gulf of
Guinea, in the eastern equatorial Atlantic (EEA), reveal centennial-
scale variations of riverine freshwater input that
... are synchronous
with northern high-latitude stadials and interstadials of the
penultimate interglacial and the last deglaciation. EEA Mg/Ca-based
sea surface temperatures (SSTs) were decoupled from northern high-
latitude millennial-scale fluctuation and primarily responded to
changes in atmospheric greenhouse gases and low-latitude solar
insolation. The onset of enhanced monsoon precipitation lags behind
the changes in EEA SSTs by up to 7000 years during glacial-interglacial
transitions. This study demonstrates that the stadial-interstadial
and deglacial climate instability of the northern high latitudes
exerts dominant control on the West African monsoon dynamics through
an atmospheric linkage. 
