Evaluating the AMOC strength for a full glacial cycle.

评估整个冰川周期的 AMOC 强度。

• 批准号: 507158203
• 负责人: Dr. Jörg Lippold
• 金额: --
• 依托单位: Forschungsbereich 2: Marine Biogeochemie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/507158203?language=en
• 关键词: Evaluating; AMOC; strength; full; glacial

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.

大西洋经向翻转环流（AMOC）通过调节盐、热、营养物质和碳的全球运输和储存，在我们星球的气候系统中扮演着重要角色。为了提供关于地球气候对扰动的响应的现实预测，我们需要对海洋环流的机械理解。在全新世，深水形成一直活跃在北大西洋和北大西洋深水（NADW）已占据了大部分的深大西洋盆地。这种循环模式通常被称为“暖”模式。对于末次冰期，在McManus等人（2004）和Böhm等人（2015）对百慕大海隆进行基准研究后，三种AMOC模式的看法得到了广泛接受。然而，一直有严肃的声音声称，百慕大海隆本身并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，我们将重建的AMOC的变化在末次冰期循环的基础上，从位置的下芯记录的NADW相对于百慕大隆起的流动路径的上游和下游。利用放射性同位素替代物，如钕同位素和铀衰变产物231 Pa和230 Th，评估北大西洋的水团分布和环流强度。这个项目的结果，独立于潜在的偏见影响目前在百慕大隆起，将代表高度要求过去的海洋参数的气候模型。