Control of Earth's climate(s) by the polar Southern Ocean

未来海洋会吸收多少热量和碳？为了帮助人类社会预测和适应全球变暖，这是科学界必须回答的最紧迫的问题之一。在几十年到千年的时间尺度上，答案主要在极地(60年代以南)的南大洋。在这里，非常密集的水在南极海岸附近形成，并下沉到深渊，驱动着全球颠覆的环流的下端，并决定了海洋在深渊中隔离热量和碳的能力，持续了几个世纪。然而，缺乏对支撑南大洋深海固存的机制的强有力的量化了解，这主要是因为在这种恶劣和偏远的环境中收集测量数据面临着巨大的挑战。该项目旨在对南大洋的深海热量和碳封存进行最先进的基线估计，以确定它们的控制过程。为了实现这一点，我将结合最近的现场海洋数据、卫星观测和最先进的建模。该项目将在南安普顿大学海洋和地球科学系与多个国家(国家海洋学中心和利物浦大学)和国际(美国斯克里普斯海洋研究所和澳大利亚CSIRO)研究所合作开展。这一分析将提供一个新的基准，以检验我们目前对南大洋在气候系统中作用的理解，并在必要时推动新模式的出现。鉴于南大洋在很长的时间尺度上调节气候，这一新知识将在项目的最后几年用来测试(并可能重温)冰川-间冰期转变和过去气候突变的机制。我将把理想化和气候模型结合起来，以便更好地理解过去的气候转变，为更好地预测地球气候系统的长期(50年)未来铺平道路。

How much heat and carbon will be taken up by the ocean in the future? This is one of the most pressing questions the scientific community must answer in order to help human society predict and adapt to global warming. On multidecadal to millennial time scales, the answer mostly lies in the polar (south of ~60S) Southern Ocean. Here, very dense water forms near the Antarctic coast and sinks to the abyss, driving the lower limb of the global overturning circulation and determining the ocean's ability to sequester heat and carbon in the abyss for centuries. However, a robust quantitative understanding of the mechanisms underpinning abyssal sequestration in the Southern Ocean is lacking, mainly due to the formidable challenges to the collection of measurements in this harsh and remote environment. The project aims to generate a state-of-the-art, baseline estimate of abyssal heat and carbon sequestration in the Southern Ocean, determining their controlling processes. To achieve this, I will combine recent in situ oceanographic data, satellite observations and stat-of-the-art modelling. The project will be carried out in the Department of Ocean and Earth Science at the University of Southampton, in collaboration with multiple national (the National Oceanography Centre and the University of Liverpool) and international (Scripps Institution of Oceanography, U.S., and CSIRO, Australia) institutes. This analysis will provide a new benchmark to test our current understanding of the Southern Ocean's role in the climate system and, if necessary, drive the emergence of a new paradigm. Given the Southern Ocean regulates climate on long time scales, this new knowledge will be used in the final years of the project to test (and possibly revisit) mechanisms of glacial-interglacial transitions and abrupt past climatic changes. I will combine idealized and climate models to better understand past climate transitions, opening the way for better predicting the long term (> 50 years) future of the Earth's climate system.