High-frequency shifts in the Indian summer monsoon following termination of the YD event

Abstract

High-resolution multi-proxy records are pivotal to analyze Indian monsoon variability and its linkages with socio-economic growth in South Asia. To constrain short-term shifts in the Indian monsoon, we analyzed a speleothem sample from Meghalaya, northeastern India encompassing ?15.4 to 10.1 kilo year before the Present (kyr BP). Our new speleothem data from Meghalaya suggests wet conditions in northeastern India during ?15.4 to 12.9 kyr BP and ?11.3 to 10.1 kyr BP, punctuated by a dry phase during ?12.9 to 11.3 kyr BP including the Younger Dryas (YD) cold interval. We suggest a southward shift of the Intertropical Convergence Zone (ITCZ) in addition to weak Atlantic Meridional Overturning Circulation and land-sea heat contrast during the YD event leading to a weak Indian summer monsoon. The Northern Hemisphere atmospheric heating shift the ITCZ northward, but our data shows high-frequency shifts in the ISM during ?11.3 to 10.1 kyr BP following termination of the YD cold event. This interval also shows a higher growth rate of the studied speleothem sample. � 2021 Elsevier Ltd