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、放大和调解全球气候变化。我的研究计划的首要长期目标是描述和量化现代和过去海洋中的大规模海洋环流。大规模的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海洋和大气之间二氧化碳分配的控制。因此，我的研究将为气候变化的速率和幅度提供独特的重要观测约束。 具体来说，我试图描述的动力学之间的关系的跨半球和跨盆地的海洋交换在西赤道太平洋晚第四纪（过去15万年）。西赤道太平洋是世界上唯一的“水团十字路口”，从太平洋通过印度尼西亚洋流流向印度洋的表层沃茨，压倒了从南半球流向北方的深层沃茨。我对世界海洋这一关键但研究不足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）印度尼西亚的洋流在过去是如何变化的？2)变化的水团来源对沿着广阔的赤道太平洋的营养状况有什么影响？3)在末次冰期-间冰期旋回中，舌状源中层和深层沃茨的环流是如何变化的？整个研究计划的主要重点将放在四个时间间隔上，这四个时间间隔共同限制了晚第四纪海洋和气候变化的全部动态范围：a）过去2,000年，以了解正在进行和预计的全球气候变化; B）全新世早期日射最大值（9,000 - 6,000年前），以评估区域气候对印度尼西亚洋流的影响，并与过去2,000年进行比较; c）末次冰期-间冰期过渡期（25，000 - 10，000年前），以确定末次自然全球变暖事件期间的变化速率和幅度;以及d）末次间冰期（125，000 - 115，000年前），以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。该研究计划还将提供先进的教育和培训，在尖端，高质量的研究，这将确保未来的研究生涯和就业的学生在与自然科学有关的有影响力的职位。