ABRUPT HOLOCENE CHANGES IN THE INDIAN OCEAN SW MONSOON AND THEIR LINKS TO NORTH ATLANTIC

The Indian Ocean southwest (SW) monsoon, one of the dominant features of the global climate, exhibited remarkable abrupt changes during the last ice age and correlation with the North Atlantic millennial-scale climate events suggests a mechanistic link. Whether smaller abrupt changes seen in the Holocene North Atlantic also correlate is a poorly resolved question with relevance to understanding and modelling future climate change. Here we exploit the potential of rapidly accumulating minimally bioturbated sediments from the anoxic Arabian Sea to produce a continuous record of centennial scale variability throughout the Holocene. The Arabian Sea sediments are nannofossil-rich foraminifer oozes, and the low oxygen content of the Arabian Sea minimizes the bioturbation that would otherwise smooth the record The monsoon proxy record from Arabian Sea reveals multiple intervals of weak summer monsoon winds coinciding with the cold spells in the Northern Hemisphere during the Holocene. The most recent change from the Medieval Warm Period through the Little Ice Age and to the present is also evident as a change in the monsoon, and we thus conclude that the North Atlantic-Asian monsoon link is a robust aspect of the global climate.