Investigating North Atlantic Circulation During the Last Deglaciation.

大西洋经向翻转环流（AMOC）作为全球海洋热、盐和营养物质输送带的组成部分，在全球气候系统中起着重要作用。由于对海洋温度升高、冰盖和海冰融化以及高纬度降水增加所带来的淡水输入敏感，AMOC的稳定性可能会在全球变暖的情况下面临风险。在过去15万年的代理记录中，AMOC的变化与温暖（冰间）和寒冷（冰间）条件之间的突然转变有关，但任何AMOC减弱的程度和相关机制并没有完全受到限制。该项目旨在调查在末次冰消期（~19-11 ka：末次冰盛期和全新世之间）记录中观察到的整个事件中北大西洋水文的变化。该项目将使用一系列古海洋学代用指标，包括可分选的淤泥、海洋碳酸盐中的氧同位素、成团同位素和微量金属分析，以重建西北大西洋三个深度断面的深海流速和温度。这些西北大西洋记录的生成将填补全流域代理数据覆盖的空白，从而促进整个末次冰消期水文地理的相对阶段和区域差异的调查。最终，这将增加我们对气候突变背后机制的理解，并为评估气候模型性能提供一个测试案例。

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.