ASYNC - Resolving asynchronous responses of North Atlantic climate to deglacial changes in ocean circulation

ASYNC - 解决北大西洋气候对海洋环流冰消变化的异步响应

• 批准号: NE/W006243/1
• 负责人: Francesco Muschitiello
• 金额: $ 69.22万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW006243%2F1
• 关键词: ASYNC; Resolving; asynchronous; responses; North

The proposed project will test the hypothesis that gradual changes in Atlantic Meridional Overturning Circulation (AMOC) -a system of surface and deep ocean currents that exerts a primary control on Earth's climate, led to abrupt shifts in North Atlantic climate during the transition out of the last ice age and into the present warm interglacial (~20,000-10,000 years ago). Greenlandic ice-core records show clear evidence that this period was characterised by major abrupt climate shifts in less than a decade, which have been attributed to changes in the AMOC regime associated with reduced northward surface heat transport in the high-latitude North Atlantic and its deep southward return flow. Critically, the anomalous weakening of the AMOC in the last decades caused by enhanced fluxes of meltwater and ice export from the Arctic in response to Arctic change prompts the question: Is the current decline in AMOC heralding a new phase of abrupt change similar to those recorded in ice cores and ocean sediments, and what is the response time of North Atlantic climate to changes in high-latitude surface and deep ocean circulation?Resolving and quantifying asynchronous changes within the coupled ocean-atmosphere system is hence essential to improve our theoretical understanding of climate processes and predictive capacity of climate models, as well as identifying under which conditions abrupt climate change occurs. ASYNC is an international collaborative project led by the University of Cambridge that will tackle this fundamental problem. The project will avail of unique North Atlantic Ocean sediment records to generate a suite of precisely dated and multidecadally-resolved proxy records of ocean circulation and climate change. ASYNC represents the first targeted effort to compare high resolution North Atlantic proxy records by precisely integrating the underlying timescales in a continuous fashion. The marine records will be synchronised to the Greenland ice-core chronology via independent and continuous reconstructions of globally synchronous variations in the incoming cosmic ray flux using multidecadally-resolved cosmogenic 10Be records from seafloor sediments and published ice cores.The proposed project will result in new cosmogenic 10Be, sea ice, meltwater discharge, and bottom- and surface-water ventilation reconstructions from three North Atlantic marine sediment cores. The palaeoceanographic reconstructions, and in particular the bottom-water ventilation records, which reflect the southward deep component of AMOC, will be directly compared to events recorded in ice-core climate reconstructions from Greenland. Together, ASYNC will result in the first network of continuously synchronised records of atmospheric, oceanic and sea ice change that will resolve the temporal and spatial propagation of North Atlantic ocean perturbations on the climate system across the major climatic transitions that punctuated the last deglaciation (~20,000-10,000 years ago). Results from ASYNC will advance the current understanding of i) the nature and timing of abrupt climate shifts across climate archives, ii) nonlinear responses of AMOC and climate to gradual Greenland Ice Sheet and Arctic sea ice meltwater forcing, and iii) ocean precursors of rapid climate change in the North Atlantic region.

拟议的项目将检验以下假设：大西洋子午倾覆循环（AMOC） - 表面和深洋流系统的逐渐变化，可以对地球气候产生主要控制，导致北大西洋气候的突然转变，从最后一个冰河时代过渡到当今的温暖冰期（〜20,000,000，000年前）。格陵兰冰核记录显示了明确的证据表明，这一时期的特征是不到十年的大发生了气候变化，这归因于与北大西洋高纬度及其深度向南回流相关的AMOC政权的变化。至关重要的是，在过去几十年中，AMOC的异常减弱是由于北极的融化和冰的增加而导致北极变化的出口量的增加引起了问题：AMOC目前的突然变化的新阶段是否与冰芯和海洋的循环范围相似？因此，量化耦合的海洋大气系统内的异步变化对于提高我们对气候过程和气候模型的预测能力的理论理解以及确定条件在哪些情况下发生气候变化的情况至关重要。 Async是由剑桥大学领导的国际合作项目，将解决这个基本问题。该项目将利用独特的北大西洋沉积物记录，以产生一套精确的日期和多年降级的海洋循环和气候变化代理记录。异步代表了第一个针对性的努力，该努力是通过以连续的方式精确整合基础时间尺度来比较北大西洋代理记录的高分辨率。海洋记录将通过使用多年胶结解的宇宙式10BE记录的独立和连续重建全球同步变化的独立和连续重建，将海洋记录同步到格陵兰冰核的年表。来自三个北大西洋海洋沉积物核心的重建。形成了反映AMOC的南部深层组成部分的古生物学重建，尤其是底水通风记录，将与格陵兰冰核气候重建中记录的事件直接进行比较。同时，异步将导致第一个连续同步的大气，海洋和海冰变化记录网络，这将解决北大西洋北大大洋对气候系统扰动的时间和空间繁殖，这些气候系统跨越了最后的气候过渡，这些过渡贯穿了最后一个deglactication the Last Deglaciation（〜20,000-10,000，000年前）。异步的结果将提高对i）气候档案中突然气候变化的性质和时机，ii）北大西洋地区气候变化的海洋前体的AMOC和气候对逐渐的格陵兰冰板和北极海冰融化的反应。

项目成果

Publisher Correction: Sea ice-ocean coupling during Heinrich Stadials in the Atlantic-Arctic gateway.

出版商更正：大西洋-北极门户海因里希体育场期间的海冰-海洋耦合。

• DOI: 10.1038/s41598-024-54224-4
• 发表时间: 2024
• 期刊: Scientific reports
• 影响因子: 4.6
• 作者: Altuna NEB

Coastal permafrost was massively eroded during the Bølling-Allerød warm period

伯林-阿勒德暖期期间，沿海永久冻土层遭到大规模侵蚀

• DOI: 10.1038/s43247-023-01013-y
• 发表时间: 2023
• 期刊: Communications Earth & Environment
• 影响因子: 7.9
• 作者: Nogarotto A

The Temporal Phasing of Rapid Dansgaard-Oeschger Warming Events Cannot Be Reliably Determined

丹斯加德-厄施格快速变暖事件的时间阶段无法可靠确定

• DOI: 10.5194/egusphere-2023-2496
• 发表时间: 2023
• 作者: Slattery J