Evaluating the AMOC strength for a full glacial cycle.

大西洋经向翻转环流（AMOC）通过调节全球盐、热、营养物质和碳的运输和储存，在地球气候系统中扮演着重要角色。为了对地球气候对扰动的反应提供现实的预测，我们需要对海洋环流有一个机械的了解。全新世以来，北大西洋深水形成活动频繁，北大西洋深水（NADW）占据了北大西洋深盆的很大一部分。这种循环模式通常被称为“暖”模式。在McManus等人（2004年）和Böhm等人（2015年）从百慕大隆起进行的基准研究之后，最后一个冰期的三种amoc模态的感知得到了广泛接受。然而，一直有严肃的声音声称，仅深百慕大上升不足以代表整个大西洋及其环流。因此，在本项目中，我们将根据NADW流动路径上游和下游相对于百慕大隆起的位置的下芯记录，重建末次冰期AMOC的变化。利用放射性成因同位素指标，如钕同位素和铀衰变产物231Pa和230Th，评价北大西洋水团分布和环流强度。这个项目的结果不受百慕大上升的潜在偏倚效应的影响，将为气候模式提供高度需要的过去海洋参数。

The Atlantic Meridional Overturning Circulation (AMOC) represents a major player in the climate system of our planet by modulating the global transport and storage of salt, heat, nutrients and carbon. In order to provide realistic predictions about the response of Earth’s climate to perturbations, we need a mechanistic understanding of ocean circulation. During the Holocene, deep water formation has been active in the North Atlantic and this North Atlantic Deep Water (NADW) has occupied a large fraction of the deep Atlantic basin. This circulation mode is often referred to as the ‘Warm’ mode. For the last glacial the perception of three AMOC-modes gained wide acceptance after the benchmark study by McManus et al. (2004) and by Böhm et al. (2015) from the Bermuda Rise. However, there has been always serious voices claiming that the deep Bermuda Rise alone is not sufficiently representative for the whole Atlantic Ocean and its circulation. As a logical consequence, in this project we will reconstruct the variability of the AMOC during the last glacial cycle based on down-core records from locations up- and down-stream the flow-path of NADW relative to the Bermuda Rise. By making use of radiogenic isotope proxies, such as Neodymium isotopes and the uranium decay products 231Pa and 230Th, water mass distribution and circulation strength in the North Atlantic will be assessed. The result from this project, independent from potentially biasing effects present at the Bermuda Rise, will represent highly demanded past oceanic parameters for climate models.