Investigating North Atlantic Circulation During the Last Deglaciation.

大西洋子午线翻转环流(AMOC)作为全球海洋热、盐和营养物质传送带的组成部分，在全球气候系统中发挥着重要作用。由于对海洋温度变暖、冰盖和海冰融化的淡水输入以及高纬度降水的增加非常敏感，在全球变暖的情况下，AMOC的稳定性可能会受到威胁。在过去150,000年的替代记录中，大气有机碳的变化与温暖(间歇)和寒冷(静止)条件之间的突变有关，但任何大气有机碳减弱的程度和相关的机制并没有完全受到限制。该项目旨在调查北大西洋水文学在最后一次冰川消融(约19-11ka：末次冰盛期与全新世之间)记录中观察到的整个事件中的变化。该项目将使用一系列古海洋学指标，包括可分选的泥沙，以及海洋碳酸盐中的氧同位素、块状同位素和痕量金属分析，以重建西北大西洋三个深度横断面的深海流速和温度。这些西北大西洋记录的产生将填补盆地范围替代数据覆盖范围的空白，从而促进对上一次冰川消融过程中水文地理的相对分期和区域差异的调查。最终，这将增加我们对气候突变背后的机制的理解，并提供一个用于评估气候模型性能的测试案例情景。

As a component of the global ocean conveyor belt of heat, salt and nutrients, the Atlantic Meridional Overturning Circulation (AMOC) plays a major part in the global climate system. Sensitive to warming ocean temperatures and freshwater input from melting ice sheets and sea-ice and increased high-latitude precipitation, the stability of AMOC may be at risk in a warming world. Variations in AMOC have been linked with abrupt shifts between warm (interstadial) and cold (stadial) conditions in proxy records of the last 150,000 years, but the extent of any AMOC weakening and the associated mechanisms are not fully constrained. This project seeks to investigate changes in North Atlantic hydrography throughout the events observed in records of the last deglaciation (~19-11 ka: between the Last Glacial Maximum and the Holocene). This project will use a range of palaeoceanographic proxies including sortable silt, and oxygen isotope, clumped isotope and trace metal analyses in marine carbonates to reconstruct deep ocean flow speed and temperature at three depth-transects in the Northwest Atlantic. The generation of these Northwest Atlantic records will fill a gap in basin-wide proxy data coverage, thus facilitating an investigation in the relative phasing and regional differences in hydrography throughout the last deglaciation. Ultimately, this will increase our understanding of the mechanisms behind abrupt climate changes and provide a test-case scenario with which to evaluate climate model performance.