Understanding the Air We Breathe: Atmospheric Composition in Urban and Arctic Environments

***我研究的首要目标是提高我们对决定大气成分和驱动大气变化的化学和物理过程的理解，这些知识对明智的决策至关重要。为了实现这一目标，我的小组开发并使用光谱仪器和数据分析工具来测量大气中的微量气体浓度，我们与大气建模人员合作，对这些测量结果进行解释。******该提案描述了一个由与对流层相关的科学问题驱动的综合研究计划，对流层是大气中化学成分复杂的区域，来自自然和人为来源的气体在相似的时间尺度上经历运输和化学处理。与人口增长、能源使用、工业活动和农业相关的排放变化正在改变污染物和温室气体的大气负担，从而影响空气质量和气候。北极是中纬度地区排放的污染物的主要接收地，但其来源存在不确定性，近几十年来全球排放分布的变化使其进一步复杂化。******建议的研究有4个短期目标，这些目标推动了4个不同的项目：***(1)描述由于当地来源和远距离运输造成的城市污染事件的起源，并量化这些事件对对流层组成的影响。***(2)确定集约化农业实践对氨和城市空气质量的影响，重点以巴黎和多伦多为基准案例研究。***(3)量化城市温室气体排放，跟踪多时间尺度上的排放异常和变化。***(4)研究北极空气质量的决定因素，评估来自亚洲、欧洲、北美和当地来源的人为污染和生物质燃烧的相对贡献。******为了实现这些目标，我们将在城市（多伦多）、农村（埃格伯特）和偏远的北极（尤里卡）地点测量微量气体浓度，同时还将结果提供给国际观测网络，并利用它们验证卫星任务的新数据产品。******本项目资助本科生10人，研究生4人，博士后1人。他们将获得与精密仪器的部署、操作和维护相关的技术技能，以及与大气测量的数值分析和解释相关的科学技能。他们还将通过撰写和展示他们的研究成果获得沟通技巧，并通过负责仪器、实地考察和合作获得领导能力、团队合作能力和解决问题的能力。这种广泛的培训和可转移技能的结合将使他们为在学术界、政府和私营部门的职业生涯做好准备。**

***The overarching goal of my research is to improve our understanding of the chemical and physical processes that determine atmospheric composition and drive atmospheric change, knowledge that is essential for informed policy-making. To achieve this goal, my group develops and uses spectroscopic instruments and data analysis tools to measure atmospheric trace gas concentrations, and we collaborate with atmospheric modellers in the interpretation of these measurements.******This proposal describes an integrated research program motivated by scientific questions related to the troposphere, a chemically complex region of the atmosphere where gases from natural and anthropogenic sources undergo transport and chemical processing on similar time scales. Changing emissions associated with increasing population, energy use, industrial activity, and agriculture are changing the atmospheric burden of pollutants and greenhouse gases, thus affecting air quality and climate. The Arctic is a major receptor for pollutants emitted at mid-latitudes, but uncertainty exists regarding sources, further complicated by changes in the global distribution of emissions in recent decades.******The proposed research has four short-term objectives, which motivate four distinct projects:***(1) To characterize the origins of urban pollution events due to local sources and long-range transport, and to quantify the impact of these episodes on tropospheric composition. ***(2) To determine the impact of intensive agricultural practices on ammonia and urban air quality, with a focus on Paris and Toronto as benchmark case studies.***(3) To quantify urban emissions of greenhouse gases and track emission anomalies and changes over multiple timescales.***(4) To investigate the determinants of air quality in the Arctic, assessing the relative contributions of anthropogenic pollution and biomass burning from Asia, Europe, North America, and local sources.******To achieve these goals, we will measure trace gas concentrations at urban (Toronto), rural (Egbert), and remote Arctic (Eureka) sites, while also contributing the resulting measurements to international observing networks and using them to validate new data products from satellite missions.******This program will support ten undergraduates, four graduate students, and one postdoctoral fellow. They will acquire technical skills associated with the deployment, operation, and maintenance of sophisticated instrumentation, and scientific skills associated with the numerical analysis and interpretation of atmospheric measurements. They will also gain communications skills through writing up and presenting their research, and leadership, teamwork, and problem-solving skills by taking responsibility for instruments, fieldwork, and collaborations. This combination of broad training and transferable skills will equip them well for careers in academia, government, and the private sector. **