Pliocene North Atlantic water mass distribution and Meridional Overturning Circulation, 3.3 - 3.0 Ma

这里提出的项目侧重于北大西洋经向翻转环流（MOC）的变化，旨在详细重建上新世（~3.3-3.0 Ma前; Piacenzian中期）最近全球暖期北大西洋的中层和深层水团分布和环流。在这30万年的时间间隔内，全球气温比今天高3°C，由于人为气候变化，预计将在本世纪结束前达到这一温度。Piacenzian中期被认为是未来全球气候最接近和最新的模拟之一。因此，它是唯一适合的案例研究，以更好地了解海洋和气候过程控制和应对全球变暖的目标。本文以北大西洋5个样带为基础，提出了（1）限制水团组成和流动模式，（2）评估上新世晚期暖期北大西洋深层和中层水环流的变化。这种系统的方法将有助于更准确地评估北大西洋MOC过去的变化及其对气候的影响，类似于我们不久的将来的环境条件下。

The project proposed here focuses on changes in the North Atlantic Meridional Overturning Circulation (MOC) and aims to provide a detailed reconstruction of intermediate and deep water mass distribution and circulation in the North Atlantic over the most recent global warm period in the Pliocene (~3.3–3.0 Ma ago; the mid-Piacenzian). During this 300 000 year interval, global temperature was ~3°C warmer than today, which has been predicted to be reached before the end of this century due to anthropogenic climate change. The mid-Piacenzian is considered to be one of the closest and the most recent analog for future global climate. It is thus uniquely suited for a case study with the goal to better understand the oceanographic and climatic processes controlling and responding to the global warming. On the basis of 5 core transects in the North Atlantic, we propose (1) to constrain the water-mass composition and flow patterns, and (2) to assess changes of North Atlantic deep and intermediate water circulation over the Upper Pliocene warm period. This systematic approach will help to more accurately evaluate the past variability of the North Atlantic MOC and its effects on climate under environmental conditions similar to our near future.