Evaluating the AMOC strength for a full glacial cycle.

大西洋子午线翻转环流(AMOC)通过调节全球盐分、热量、营养物质和碳的运输和储存，代表着地球气候系统中的一个主要参与者。为了提供关于地球气候对扰动的反应的现实预测，我们需要对海洋环流的机械理解。在全新世期间，北大西洋的深水形成活跃，这种北大西洋深水(NADW)占据了大西洋深水盆地的很大一部分。这种循环模式通常被称为“暖”模式。在最后一次冰期，在McManus等人的基准研究之后，对三种AMOC-模式的感知得到了广泛的接受。(2004)和Böhm等人所著。(2015)来自百慕大隆起。然而，一直有严肃的声音声称，仅有百慕大深部隆起不足以代表整个大西洋及其环流。作为一个合乎逻辑的结果，在这个项目中，我们将根据NADW相对于百慕大隆起的流动路径的上游和下游位置的岩心下记录，重建上一次冰川周期中AMOC的变化。通过使用放射性同位素替代物，如钕同位素和铀衰变产物231Pa230th，将评估北大西洋的水团分布和环流强度。该项目的结果独立于百慕大海隆存在的潜在偏差影响，将代表气候模型对过去海洋参数的高度要求。

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.