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; 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.

作为全球热，盐和养分的全球海洋传送带的组成部分，大西洋子午翻转循环（AMOC）在全球气候系统中起着重要作用。对温暖的海洋温度和淡水输入敏感，来自融化的冰盖和海冰，以及增加的高纬度降水，在温暖的世界中，AMOC的稳定性可能会面临风险。 AMOC的变化与过去150，000年的代理记录中的温暖（内部）和寒冷（体型）条件之间的突然变化有关，但是任何AMOC弱化的程度和相关机制的程度均未完全限制。该项目旨在调查北大西洋水文的变化，这在最后一次脱气记录中观察到的（〜19-11 ka：在最后的冰川最大值和全新世之间）。该项目将使用一系列的古生证代理，包括可排序的淤泥，氧同位素，集结的同位素和痕量金属分析，以在西北大西洋的三个深度转换下重建深海流速和温度。这些西北大西洋记录的产生将填补盆地范围内代理数据覆盖范围的空白，从而促进了整个最后一次脱水过程中对水文的相对相相和区域差异的研究。最终，这将增加我们对突然气候变化背后机制的理解，并提供评估气候模型性能的测试案例。