900ka variability of the North Atlantic deep water mass Nd composition

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The Atlantic Meridional Overturning Circulation (AMOC) is a key player in the global climate system due to its large contribution regarding matter and heat transport across the hemispheres. Neodymium isotopes stored in the authigenic fraction of deep Atlantic sediments have been proven valuable tools to record such provenance changes across major and millennial climate variations. Therefore, in this proposed project we investigate this process of water mass competition in the deep North Atlantic over the past 1 million years at partly millennial resolution to reconstruct the long term evolution of deep water across numerous climate cycles. Moreover, we intend to retrieve the long term frequency of changes and possibly even discover yet unrecorded Dansgard/Oeschger events from deep sea sediments. The latter seems possible as a previous study has revealed a strong link between deep water Nd isotope composition and D/O events during the past 150ka (Böhm et al., 2015). The site of choice is the deep sea sediment core at ODP Leg 172 Site 1063, where measurements of authigenic Nd isotopes in Fe /Mn -leachates have successfully traced changes of deep water provenance related to millennial climate change (Böhm et al., 2015). Moreover, our first results from this project have revealed a unique pattern across MIS 11 and thus termination V. Within the frame of this project we intend to accomplish and complete the work initiated improving the time resolution of the record. The record established through this project has the potential to become an invaluable benchmark for the link between climate and deep water provenance in the Northwest Atlantic that will strongly improve our understanding of ocean - climate feedbacks.