Global ocean circulation during the late Quaternary: Paleoceanographic constraints from the Western Equatorial Pacific

晚第四纪全球海洋环流：来自西赤道太平洋的古海洋学限制

• 批准号: RGPIN-2022-03064
• 负责人: Kienast, Markus
• 金额: $ 3.13万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761596
• 关键词: Global; ocean; circulation; during; late

The ocean initiates, amplifies and mediates global climate change on time scales ranging from less than a year to thousands of years. The overarching long-term goal of my research program is to characterize and quantify large-scale ocean circulation both in the modern and past ocean. Large-scale ocean circulation plays a pivotal role in global climate, for example through the redistribution of heat and its control on the partitioning of carbon dioxide, CO2, between the ocean and atmosphere. My research will, therefore, provide uniquely important observational constraints on rates and amplitudes of climate change. Specifically, I seek to characterize the dynamic relationship between the cross-hemispheric and inter-basin ocean exchanges in the Western Equatorial Pacific during the late Quaternary (the last 150,000 years). The Western Equatorial Pacific is the world's only "water mass crossroad", where surface waters flowing from the Pacific to the Indian Ocean through the Indonesian Throughflow are overriding deeper waters flowing from the southern to the northern hemispheres. My research of this pivotal - but much understudied - region of the world's ocean will address critical gaps in our understanding, with a particular focus on three interlinked short-term objectives: 1) How did the Indonesian Throughflow vary in the past? 2) What is the effect of changing water mass sources on the nutrient conditions along the vast equatorial Pacific? 3) How did the circulation of Antarctic-sourced intermediate and deep waters change during the last glacial-interglacial cycle? The primary focus of the overall research program will be on four time intervals, which together constrain the full dynamic range of ocean and climate change during the late Quaternary: a) the last 2,000 years, to contextualize ongoing and projected global climate change; b) the early Holocene insolation maximum (9,000 - 6,000 years ago), to assess the effect of regional climate on the Indonesian Throughflow compared the last 2,000 years; c) the last glacial-interglacial transition (25,000 - 10,000 years ago), to establish rates and amplitudes of change during the last natural global warming event; and d) the last interglacial period (125,000 - 115,00 years ago), to compare to the present interglacial. Understanding past ocean and climate variability is key to understanding the present-day ocean-climate system and for modelling future global climate change in the Anthropocene. My research program will continue to contribute critically needed quantitative constraints on past ocean and climate change. The research program will also provide advanced education and training in cutting-edge, high-quality research, which will ensure future research careers and employment of my students in impactful positions related to natural science.

海洋在不到一年到数千年的时间尺度上引发、放大和调节全球气候变化。我的研究计划的总体长期目标是表征和量化现代和过去海洋的大规模海洋环流。大规模海洋环流在全球气候中发挥着关键作用，例如通过热量的重新分配及其对二氧化碳在海洋和大气之间的分配的控制。因此，我的研究将为气候变化的速率和幅度提供独特重要的观测限制。 具体来说，我试图描述第四纪晚期（过去15万年）西赤道太平洋跨半球和跨盆地海洋交换之间的动态关系。西赤道太平洋是世界上唯一的“水团十字路口”，从太平洋经印度尼西亚贯流流向印度洋的地表水压倒了从南半球流向北半球的深层水域。我对世界海洋这一关键但尚未充分研究的区域的研究将解决我们理解中的关键差距，特别关注三个相互关联的短期目标：1）印度尼西亚通流过去如何变化？ 2）水体来源的变化对广阔的赤道太平洋沿岸的营养条件有何影响？ 3）末次冰期-间冰期循环期间，源自南极的中层水和深层水的环流发生了怎样的变化？整个研究计划的主要重点将集中在四个时间间隔上，它们共同限制了第四纪晚期海洋和气候变化的完整动态范围：a）过去2000年，以了解当前和预计的全球气候变化的背景； b) 全新世早期日照最大值（9,000 - 6,000 年前），以评估区域气候对过去 2,000 年印度尼西亚贯穿流量的影响； c) 最后一次冰期-间冰期转变（25,000 - 10,000 年前），以确定最后一次全球自然变暖事件期间的变化率和幅度； d) 最后一个间冰期（125,000 - 115,00 年前），与现在的间冰期进行比较。了解过去的海洋和气候变化是了解当今海洋气候系统和模拟人类世未来全球气候变化的关键。我的研究计划将继续为过去的海洋和气候变化提供急需的定量限制。该研究项目还将提供尖端、高质量研究方面的先进教育和培训，这将确保我的学生未来的研究生涯和就业，并担任与自然科学相关的有影响力的职位。