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

海洋在不到一年到数千年的时间尺度上启动、放大和调节全球气候变化。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。大规模海洋环流在全球气候中发挥着举足轻重的作用，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分配的控制。因此，我的研究将为气候变化的速度和幅度提供独特重要的观测约束。具体地说，我试图描述第四纪晚期(最后150,000年)赤道西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”，从太平洋流经印度尼西亚流到印度洋的表层水淹没了从南半球流向北半球的较深水域。我对这个关键但研究不足的世界海洋区域的研究将解决我们在认识上的关键差距，特别关注三个相互关联的短期目标：1)印度尼西亚的径流在过去是如何变化的？2)水团的变化对广阔的赤道太平洋沿岸的营养条件有什么影响？3)在上一个冰期-间冰期周期中，起源于南极的中深层水域的循环是如何变化的？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第四纪晚期海洋和气候变化的全部动态范围：a)过去2000年，以联系正在进行的和预计的全球气候变化；b)全新世早期日照最大值(9000-6000年前)，以评估与过去2000年相比区域气候对印度尼西亚径流的影响；c)最后一次冰川-间冰期转变(25,000-10,000年前)，以确定上一次自然全球变暖事件期间的变化速度和幅度；以及d)最后一个间冰期(125,000-115，00年前)，与现在的间冰期相比较。了解过去的海洋和气候变异性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对过去的海洋和气候变化做出亟需的数量限制。该研究计划还将提供尖端、高质量研究方面的高级教育和培训，这将确保我的学生未来的研究生涯和就业在与自然科学相关的有影响力的职位上。

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.