Nitrogen oxides in remote tropical ocean environments and their impact on air pollution and climate

氮氧化物（NOx = NO+NO2）在大气化学中起着核心作用，控制着关键空气污染物和气候气体（如甲烷，臭氧和颗粒物）的产生和损失。氮氧化物是人类活动在陆地上排放的，在偏远的海洋环境中，氮氧化物的水平通常很低，但仍然控制着这些环境中的关键大气过程。由于地球海洋的大小，氮氧化物水平的微小变化可能会对大气对排放变化的反应产生巨大影响。最近的工作突出表明，我们在了解偏远海洋环境中的氮氧化物方面存在明显的知识差距，如果我们要制定有效的政策来解决空气污染，气候和生态系统健康问题，就需要解决这些问题。这个博士项目将使用一个新开发的仪器，使氮氧化物在一个遥远的热带大西洋环境中的高灵敏度测量，并使用这些数据来推进我们的大气化学的这一基石的知识。在偏远的海洋环境中的氮氧化物的研究的一个主要挑战是，水平是如此之低，他们接近或低于当前技术的检测极限。约克大学的沃尔夫森大气化学实验室最近建造了一台基于激光诱导荧光（NO-LIF）的新仪器，用于高灵敏度和选择性地检测NO。这台仪器是世界上第二台此类仪器，将能够以前所未有的准确度和精度测量NOx，通过与来自科学计算模型的数据进行比较，将使我们对这一重要化学的理解受到挑战和改进。该博士项目将是第一个使用这种新仪器的项目，并将围绕以下目标：-协助开发和表征用于检测NO和NO2的新型NO-LIF仪器。研究NO-LIF仪器区分不同NO同位素的独特能力，以探索遥远的海洋NO来源。在佛得角大气观测站部署该仪器-通过与模式预测进行比较，利用佛得角的数据挑战和改进我们对遥远海洋大气化学的理解，以及其对区域空气污染和气候的影响。这项工作将填补我们对大气化学理解方面的一个重要知识空白，从而直接提高我们设计有效环境政策的能力。

Nitrogen oxides (NOx = NO+NO2) play a central role in the chemistry of the atmosphere, controlling both the production and loss of key air pollutants and climate gases such as methane, ozone, and particulate matter. Primarily emitted by human activity over land, NOx levels are typically very low in remote ocean environments, and yet still regulate key atmospheric processes in these environments. Due to the size of the Earth's oceans, small changes in NOx levels can have large impacts on the atmospheres response to changing emissions. Recent work has highlighted significant apparent knowledge gaps in our understanding of NOx in remote ocean environments, which need to be addressed if we are to inform effective policies to tackle air pollution, climate and ecosystem health. This PhD project will use a newly developed instrument to make highly sensitive measurements of NOx in a remote tropical Atlantic environment, and use these data to advance our knowledge of this keystone of atmospheric chemistry.A major challenge in the study of NOx in remote ocean environments is that levels are so low that they are close to or below the limits of detection of current technologies. The Wolfson Atmospheric Chemistry Laboratories at the University of York have recently built a new instrument, based on laser-induced fluorescence (NO-LIF), for the highly sensitive and selective detection of NO. This instrument, the second of its kind in the world, will enable measurements of NOx with previously unprecedented levels of accuracy and precision, and through comparison with data from state-of-the-science computation models will allow our understanding of this important chemistry to be challenged and improved. This PhD project will be the first to use this new instrument and will be based around the following objectives: - Assist in the development and characterisation of the new NO-LIF instrument for detection of NO and NO2.- Investigate the unique ability of the NO-LIF instrument to distinguish between different NO isotopes to explore remote ocean NO sources.- Deploy the instrument at the Cape Verde Atmospheric Observatory - Use the Cape Verde data to challenge and improve our understanding of remote ocean atmospheric chemistry, through comparison with model predictions, and its impact on regional air pollution and climate.This work will address an important knowledge gap in our understanding of atmospheric chemistry and thus directly improve our ability to design effective environmental policies.