Combined application of new proxies (231Pa/230Th and Nd isotopes) to reconstruct the deep ocean overturning over the last 30,000 years.

大西洋经向翻转环流在我们星球的气候系统中扮演着关键角色，因为它控制着全球热量和二氧化碳的输送。为了估计或模拟北大西洋深水出口未来的演变，至关重要的是重建北大西洋深水出口在过去主要气候转变中的强度，例如在最后一次冰川消融期间。关于最近大西洋环流的稳定，在最后一次终止期间触发短时间但极端寒冷事件的问题引起了高度关注。与现代情况相比，几个代理人指出，在最后一次冰川时期，水团分布的结构非常不同。然而，对于环流强度的变化或重大变化的时间，目前仍未达成共识。从海洋沉积物中提取的钚、钍和钕同位素是重建过去深海水文和水体输出的很有前途的新替代品。首次在西大西洋的同一沉积物样品上联合应用这些示踪剂，将极大地提高对这两个同位素系统的理解以及我们对过去大洋环流的了解。理想情况下，一个代理将提供有关翻转循环率的信息，而另一个代理将携带水团来源信号。

The Atlantic Meridional Overturning Circulation holds a key role in the climatic system of our planet as it controls the transport of global heat and CO2. In order to estimate or model its future evolution it is crucial to reconstruct the strength of the North Atlantic Deep Water Export in past major climatic transitions such as during the last deglaciation. Regarding the recent stability of the Atlantic circulation the triggers of short-time but extreme cold events during the last termination are of high interest. In contrast to the modern situation, several proxies point to a very different structure of water mass distribution during the Last Glacial. However, there is still no consensus about the variations of the circulation strength or the timing of the major changes. Protactinium, thorium, and neodymium isotopes, extracted from marine sediments, are promising novel proxies to reconstruct the past Deep Ocean hydrography and water mass export. The first time combined application of these tracers on the same sediment samples from the West Atlantic will vitally improve the understanding of both isotopic systems as well as our knowledge about the past Ocean Circulation. Ideally, one proxy will yield information about the rate of overturning circulation, whereas the other proxy carries a water mass provenance signal.