Understanding the role of Antarctic sea ice in dense water formation and heat and carbon sequestration: from satellite altimetry to 'big data' analysi

了解南极海冰在稠水形成以及热量和碳封存中的作用：从卫星测高到“大数据”分析

• 批准号: 2603979
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2603979
• 关键词: Understanding; role; Antarctic; sea; ice

The ocean is the largest carbon reservoir in the Earth system and it stores over 90% of the excess heat produced by anthropogenic activities. The rate at which both heat and carbon are absorbed by the ocean varies strongly, both in space and time, and the Southern Ocean is a key region for the uptake of both. However, we have limited skills in predicting how this will change in the future. Ice-ocean-atmosphere interactions are key in determining the rates of carbon and heat uptake by the ocean. Antarctic sea ice formation/export and circumpolar westerly winds are the dominant surface forcings in the Southern Ocean, driving the upwelling and ventilation of the dense waters that fill most of the ocean's interior and the formation of Antarctic Bottom Water, a key component of the global abyssal circulation. Polynyas - seasonal openings in the sea ice - are the other main contributors to the formation of deep and dense shelf waters around the Antarctic margins. However, Southern Ocean dynamics and circulation are poorly simulated in coupled climate models. Even state-of-the-art simulations fail to represent both ice-ocean-atmosphere interactions and biogeochemical processes adequately, and observations in these regions are scarce and patchy.MethodsSatellite along-track altimetry data in Antarctic sea ice leads will be used to analyse the ocean's sea level inside polynyas, to identify the fingerprints of dense water formation and circulation. To this end, Sea Surface Height and Sea Height Anomaly products will be processed and analysed from both the CryoSat-2 (European Space Agency) and ICESat-2 (NASA) Polar satellite missions.The representation of processes driving deep water formation and circulation in the Southern Ocean (such as winds and sea ice dynamics) will be assessed in state-of-the-art simulations from the 6th Coupled Model Intercomparison Project (CMIP6). This will be achieved by setting up advanced cloud-based computing capabilities (e.g. Pangeo) and using statistical tools and machine learning techniques to identify and explore the key relationships between ice-ocean-atmosphere processes and interactions.These combined results will be used to determine the effect of Antarctic sea ice on ocean circulation and heat/carbon uptake, improve our understanding of present and past trends, and more skillfully predict how these may change in the future.TrainingThe orbits of CryoSat-2 and ICESat-2 were partially aligned in 2020, to provide a unique dataset of coincident measurements from the satellites and increase the accuracy of sea ice measurements around Antarctica. Project work will include a hosted international visit at NASA, where ICESat-2 sea ice data are being developed. In addition, the CMIP6 archive of simulations has recently become available and will contribute to the 6th assessment report of the Intergovernmental Panel for Climate Change (IPCC).These recent advances in both numerical modelling and satellite remote sensing make such a project especially timely, while the ability to process and interpret these types of data products is among the most in-demand skills in international environmental research. This PhD will enable the student to develop proficiency in these techniques, including computer programming and handling 'big data' archives, with the support of an international team with a diverse range of expertise.The student will be based at the National Oceanography Centre in Southampton and work closely with supervisors based at the University of Leeds, where the student will be registered, the University of Southampton and the British Antarctic Survey. There will be opportunities to participate in Antarctic research cruises.

The ocean is the largest carbon reservoir in the Earth system and it stores over 90% of the excess heat produced by anthropogenic activities.海洋吸收的热量和碳在时空上都有很大的变化，而南大洋则是吸收两者的关键区域。但是，我们在预测未来将如何变化方面的技能有限。冰山 - 大气相互作用是确定海洋碳和热吸收速率的关键。南极海冰形成/出口和圆极西风是南大洋中的主要表面刺激，驱动着填充大部分海洋内部和南极底部水的茂密水的上升和通风，这是全球深度循环的关键组成部分。 Polynyas-海冰中的季节性开口 - 是在南极边缘周围形成深而密集的架子水域的另一个主要因素。但是，在耦合的气候模型中，南洋动力学和循环量很差。 Even state-of-the-art simulations fail to represent both ice-ocean-atmosphere interactions and biogeochemical processes adequately, and observations in these regions are scarce and patchy.MethodsSatellite along-track altimetry data in Antarctic sea ice leads will be used to analyse the ocean's sea level inside polynyas, to identify the fingerprints of dense water formation and circulation.为此，将从CryoSat-2（欧洲航天局）和ICESAT-2（NASA）极地卫星任务中处理和分析海面高度和海高度异常产品。在驱动南方海洋深水形成和循环的过程（例如风和海冰动力学）的过程中，将在6th coupled的couparem inter-proppition中评估（例如，风力和海冰动力学）的深水形成和循环。 This will be achieved by setting up advanced cloud-based computing capabilities (e.g. Pangeo) and using statistical tools and machine learning techniques to identify and explore the key relationships between ice-ocean-atmosphere processes and interactions.These combined results will be used to determine the effect of Antarctic sea ice on ocean circulation and heat/carbon uptake, improve our understanding of present and past trends, and more skillfully predict how these may change in the future.TrainingThe冷冻-2和ICESAT-2的轨道在2020年部分排列，以提供独特的数据集，这些数据集来自卫星的一致测量结果，并提高了南极周围海冰测量的准确性。项目工作将包括在NASA进行的国际访问，该访问正在开发ICESAT-2海冰数据。此外，CMIP6模拟档案最近已获得，并将有助于政府间气候变化小组（IPCC）的第六次评估报告。这些数字建模和卫星遥感的最新进展尤其是及时的，而这些项目尤其及时，而这些项目的能力和解释这些类型的数据产品的能力是最大程度地环境研究中的最多范围内的国际环境研究。该博士将使学生能够在这些技术（包括计算机编程和处理“大数据”档案中的熟练程度，并在具有多种专业知识的国际团队的支持下进行。该学生将位于南安普敦的国家海洋学中心，并与利兹大学的主管密切合作，该学生将在该大学注册，在那里注册了Southampton和Southampton and the Mellyant and andarctic and andarctic。将有机会参加南极研究巡游。