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。在几十年至千年的时间尺度上，答案主要在于极地（~60S以南）南大洋。在这里，非常稠密的水在南极海岸附近形成，并沉入深渊，推动了全球翻转环流的低端，并决定了海洋在几个世纪以来将热量和碳封存在深渊中的能力。然而，目前还缺乏对南大洋深海封存机制的有力定量理解，这主要是由于在这种恶劣和偏远的环境中收集测量数据面临巨大挑战。该项目旨在对南大洋的深海热量和碳封存产生最先进的基线估计，确定它们的控制过程。为了实现这一目标，我将结合最近的原位海洋学数据、卫星观测和最先进的模型。该项目将在南安普敦大学海洋与地球科学系开展，并与多个国家（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学研究所和澳大利亚CSIRO）研究所合作。这一分析将为检验我们目前对南大洋在气候系统中的作用的理解提供一个新的基准，并在必要时推动新范式的出现。考虑到南大洋在长时间尺度上调节着气候，这一新知识将在项目的最后几年用于测试（并可能重新审视）冰期-间冰期过渡和过去气候突变的机制。我将把理想化模型和气候模型结合起来，以更好地理解过去的气候变化，为更好地预测地球气候系统的长期（大约50年）未来开辟道路。

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.