TY - JOUR
T1 - End of Green Sahara amplified mid- to late Holocene megadroughts in mainland Southeast Asia
AU - Griffiths, Michael L.
AU - Johnson, Kathleen R.
AU - Pausata, Francesco S. R.
AU - White, Joyce C.
AU - Henderson, Gideon M.
AU - Wood, Christopher T.
AU - Yang, Hongying
AU - Ersek, Vasile
AU - Conrad, Cyler
AU - Sekhon, Natasha
N1 - Funding Information:
We thank Bounheuang Bouasisengpaseuth, Norseng Sayvongdouane, Sengphone Keo-phanhya and other participants in the Middle Mekong Archeological Project and Lao government officials and departments for their assistance with the fieldwork, which was funded in part by Henry Luce Foundation grant to the University of Pennsylvania Museum. We thank Russell N. Drysdale for useful discussions, and Dachun Zhang and John Southon for help with anlayses. The climate research was supported by National Science Foundation awards 1405472 and 1603056 to K.R.J., and awards 1404932 and 1602947 to M.L.G. F.S.R.P. acknowledges funding from the Swedish Research Council (FORMAS) as part of the Joint Programming Initiative on Climate and the Belmont Forum for the project “Palaeo-constraints on Monsoon Evolution and Dynamics (PACMEDY). In addition, we acknowledge support from the NSF Doctoral Dissertation Improvement Grant #1724202 awarded to C.C. This research was also supported by a 2010–2012 NOAA/UCAR Climate and Global Change Postdoctoral Fellowship to M.L.G.
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Between 5 and 4 thousand years ago, crippling megadroughts led to the disruption of ancient civilizations across parts of Africa and Asia, yet the extent of these climate extremes in mainland Southeast Asia (MSEA) has never been defined. This is despite archeological evidence showing a shift in human settlement patterns across the region during this period. We report evidence from stalagmite climate records indicating a major decrease of monsoon rainfall in MSEA during the mid- to late Holocene, coincident with African monsoon failure during the end of the Green Sahara. Through a set of modeling experiments, we show that reduced vegetation and increased dust loads during the Green Sahara termination shifted the Walker circulation eastward and cooled the Indian Ocean, causing a reduction in monsoon rainfall in MSEA. Our results indicate that vegetation-dust climate feedbacks from Sahara drying may have been the catalyst for societal shifts in MSEA via ocean-atmospheric teleconnections.
AB - Between 5 and 4 thousand years ago, crippling megadroughts led to the disruption of ancient civilizations across parts of Africa and Asia, yet the extent of these climate extremes in mainland Southeast Asia (MSEA) has never been defined. This is despite archeological evidence showing a shift in human settlement patterns across the region during this period. We report evidence from stalagmite climate records indicating a major decrease of monsoon rainfall in MSEA during the mid- to late Holocene, coincident with African monsoon failure during the end of the Green Sahara. Through a set of modeling experiments, we show that reduced vegetation and increased dust loads during the Green Sahara termination shifted the Walker circulation eastward and cooled the Indian Ocean, causing a reduction in monsoon rainfall in MSEA. Our results indicate that vegetation-dust climate feedbacks from Sahara drying may have been the catalyst for societal shifts in MSEA via ocean-atmospheric teleconnections.
KW - atmospheric dynamics
KW - Paleoclimate
UR - http://www.scopus.com/inward/record.url?scp=85089703772&partnerID=8YFLogxK
U2 - 10.1038/s41467-020-17927-6
DO - 10.1038/s41467-020-17927-6
M3 - Article
C2 - 32826905
SN - 2041-1723
VL - 11
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 4204
ER -