Shelf seas as sources and sinks of the greenhouse gases nitrous oxide, methane and carbon dioxide.

自工业革命以来，大气中长期存在的温室气体二氧化碳(CO2)、甲烷(CH4)和一氧化二氮(N2O)的含量一直在增加，这主要是人类活动的结果。这些增加导致全球变暖和海洋酸化，后者是通过海洋净吸收二氧化碳来实现的。陆架海在全球碳和氮循环中发挥着重要作用。陆架海季节性分层的生物生产从大气中去除二氧化碳，固定的碳随后可以被出口到邻近的深海，这一过程被称为陆架-海碳泵。陆架海是大气中CH4和N2O的来源，但这些排放的大小和变化非常不确定。甲烷和N2O的产生抵消了陆架海碳泵的气候效益。气候变化、富营养化、低氧和海洋酸化可能影响陆架海气海三种气体的通量。这一雄心勃勃的博士项目旨在量化大北海和凯尔特海三种温室气体的来源和汇及其季节变化，并了解潜在的物理、化学和生物过程。新型、高精度、集成腔输出光谱分析仪现在可以同时测量所有三种气体。用于连续分析地表水和海洋空气中CH4、N2O和CO2浓度的自主船上系统将在Cefas Endeavour号上安装和运行1.5年，Cefas Endeavour号是一艘在大北海和凯尔特海作业的科考船。纪念品和SOCAT合成产品将提供温室气体的额外历史数据。辅助参数(海面温度、盐度、荧光)将有助于确定与大陆架海温室气体热点有关的过程。温室气体测量将与卫星和再分析数据(风速、海面温度、海洋颜色、混合层深度)和测绘技术(多元线性回归)相结合，以量化海-气通量及其季节变化。这一最先进的项目汇集了环境、渔业和水产养殖中心(CEFAS)和东英吉利大学(UEA)经验丰富的科学家。它将UEA在海洋生物地球化学方面的专业知识与Cefas对英国大陆架水域的了解和访问结合在一起。这位博士生将与Cefas海洋气候变化中心的科学家合作，从这项研究中获得与政策相关的信息，并将出版几本影响力较大的科学出版物和一篇博士论文。NERC工业案例学生完全融入了环境东区NERC博士培训伙伴关系(EnvEast DTP)的培训，该伙伴关系是由UEA牵头的。该项目通过培养下一代研究和商业领袖的杰出成员，投资于世界级的研究和技能。这一及时研究的主要受益者是全球气候科学家、政策制定者和普通公众。大北海和凯尔特海三种温室气体的海气通量时间序列为1.5年，这将为确定未来的变化提供一个重要的基准。这一博士项目是迈向新一代自主、高精度的N2O、CH4和CO2仪器的关键步骤，这些仪器可在机会号船上运行，因此将直接惠及欧洲综合碳观测系统。这项研究是对英国大陆架海洋生物地球化学和温室气体排放及反馈方案的补充。结果将通过向Memento和SOCAT提交数据，纳入区域和全球生物地球化学模型以及全球甲烷和碳预算。这种建模和温室气体核算为政府间气候变化专门委员会的评估以及(国际)国家海洋和气候变化政策提供信息。

The atmospheric content of the long-lived greenhouse gases carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) has been increasing since the industrial revolution, largely as a result of human activity. These increases lead to global warming and ocean acidification, the latter by net ocean uptake of CO2. Shelf seas play an important role in the global carbon and nitrogen cycles. Biological production in seasonally stratified shelf seas removes CO2 from the atmosphere and the fixed carbon can subsequently be exported to the adjacent deep ocean, a process known as the shelf-sea carbon pump. Shelf seas are sources of CH4 and N2O to the atmosphere, but the magnitude and the variation of these emissions are highly uncertain. The production of CH4 and N2O counteracts the climate benefits of the shelf-sea carbon pump. Climate change, eutrophication, hypoxia and ocean acidification may affect the air-sea fluxes of the three gases in shelf seas. This ambitious PhD project aims to quantify the sources and sinks and their seasonal variation for the three greenhouse gases in the Greater North Sea and the Celtic Sea, as well as to understand the underlying physical, chemical and biological processes. New, high-precision, integrated cavity output spectroscopy analysers now allow the simultaneous measurement of all three gases. An autonomous shipboard system for continuous analysis of CH4, N2O and CO2 concentrations in surface water and marine air will be installed and operated for 1.5 year on the Cefas Endeavour, a research vessel which operates in the Greater North Sea and the Celtic Sea. The MEMENTO and SOCAT synthesis products will provide additional, historic data for the greenhouse gases. Ancillary parameters (sea surface temperature, salinity, fluorescence) will help identify processes associated with greenhouse gas hotspots in the shelf seas. Greenhouse gas measurements will be combined with satellite and reanalysis data (wind speed, sea surface temperature, ocean colour, mixed layer depth) and a mapping technique (multiple linear regression) for quantification of air-sea gas fluxes and their seasonal variation. The state-of-the-art project brings together highly experienced scientists at the Centre for Environment, Fisheries and Aquaculture (Cefas) and the University of East Anglia (UEA). It combines UEA's expertise in marine biogeochemistry with Cefas' knowledge of and access to UK shelf waters. The PhD student will collaborate with scientists at the Cefas' Marine Climate Change Centre to obtain policy-relevant information from this research and will publish several high-impact, scientific publications and a PhD thesis. NERC Industrial CASE students are fully integrated into the training of the Environment East NERC Doctoral Training Partnership (EnvEast DTP), that UEA leads. The project invests in world-class research and skill by training an exceptional member of the next generation of research and business leaders. The main beneficiaries of this timely research are global climate scientists, policy makers and the general public. The 1.5-year time series of air-sea fluxes of the three greenhouse gases in the Greater North Sea and the Celtic Sea will provide an essential benchmark against which future changes can be identified. This PhD project presents key steps towards a new generation of autonomous, high-precision instruments for N2O, CH4 and CO2 for operational use on ships of opportunity and will therefore be of direct benefit to the European Integrated Carbon Observation System. This research complements the UK Shelf Sea Biogeochemistry and Greenhouse Gas Emissions and Feedbacks programmes. The results will feed into regional and global biogeochemical models and the Global Methane and Carbon Budgets via data submission to MEMENTO and SOCAT. Such modelling and greenhouse gas accounting inform assessments by the Intergovernmental Panel on Climate Change and (inter-)national marine and climate change policy.