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

大西洋经向翻转环流 (AMOC) 对跨半球的物质和热量传输做出了巨大贡献，因此在全球气候系统中发挥着重要作用。存储在大西洋深部沉积物自生部分中的钕同位素已被证明是记录主要和千年气候变化中此类起源变化的宝贵工具。因此，在这个拟议的项目中，我们以部分千年分辨率研究过去一百万年北大西洋深处水团竞争的过程，以重建深水在多个气候周期中的长期演化。此外，我们打算检索变化的长期频率，甚至可能从深海沉积物中发现尚未记录的 Dansgard/Oeschger 事件。后者似乎是可能的，因为之前的研究揭示了深水 Nd 同位素组成与过去 150ka 期间的 D/O 事件之间存在密切联系（Böhm 等人，2015）。选择的地点是 ODP Leg 172 Site 1063 的深海沉积物岩心，其中铁/锰渗​​滤液中自生 Nd 同位素的测量已成功追踪与千年气候变化相关的深水来源变化（Böhm 等，2015）。此外，我们这个项目的第一个结果揭示了 MIS 11 中的独特模式，因此终止了 V。在这个项目的框架内，我们打算完成并完成提高记录时间分辨率的工作。通过该项目建立的记录有可能成为西北大西洋气候与深水起源之间联系的宝贵基准，这将极大地提高我们对海洋气候反馈的理解。

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.