Investigating North Atlantic Circulation During the Last Deglaciation.

调查末次冰消期期间的北大西洋环流。

• 批准号: 2843423
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2843423
• 关键词: Investigating; North; Atlantic; Circulation; During

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.

大西洋经向翻转环流（AMOC）是全球海洋热、盐和营养物质传送带的一个组成部分，在全球气候系统中起着重要作用。在全球变暖的情况下，AMOC的稳定性可能会受到海洋温度升高、冰盖和海冰融化带来的淡水输入以及高纬度降水增加的影响。在过去15万年的代理记录中，AMOC的变化与暖（间期）和冷（静）条件之间的突变有关，但AMOC减弱的程度及其相关机制并未完全受限。该项目旨在研究在末次消冰（~19-11 ka：末次极大期和全新世之间）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指标，包括可分类淤泥、氧同位素、团块同位素和海洋碳酸盐中的痕量金属分析，重建西北大西洋三个深度样带的深海流速和温度。这些西北大西洋记录的生成将填补全盆地代用数据覆盖的空白，从而促进了对整个末次消冰期水文学的相对阶段和区域差异的研究。最终，这将增加我们对气候突变背后机制的理解，并提供一个评估气候模式性能的测试案例。