Collaborative Research: Characterization of Sources and Processes of Primary and Secondary Particulate Matter (PM) and Precursor Gases in the California-Mexico Border Region

加利福尼亚-墨西哥边境地区由于人口众多且不断扩大、工业增长、交通和农业而遭受严重的空气污染。 在该项目中，研究人员将通过收集和分析实地数据，调查污染物的跨境运输及其对区域空气质量和气候的影响。 这项工作的观测部分包括沿沿着加利福尼亚-墨西哥边界地区进行地面测量，利用一个中央固定地点和一个移动的实验室，前者将放置最先进的仪器，测量气体、气溶胶、辐射和气象参数，后者可利用涡动协方差测量地表-大气交换通量。这项研究将得到墨西哥同事在固定地点和几个移动的单位提供的标准污染物和气象参数的测量结果的补充。 主要科学目标是：（1）确定加利福尼亚-墨西哥边境地区主要排放源的排放特征，（2）确定温室气体和传统空气污染物人为排放的时空变异性，（3）阐明这些排放的迁移和转化，评估其对当地和区域空气质量和气候的影响。 NOAA和加州空气资源委员会计划进行的一项研究将提供更多的数据，以帮助分析这些问题。该项目的知识价值是评估边境地区颗粒物及其前体物的来源和加工过程及其对区域空气质量和气候的影响。 分析任务将更好地确定排放和二次粒子形成的相互作用、空气质量下降条件下细颗粒物化学成分的日变化、气溶胶特别是含烟尘粒子的大气处理及其传输和转化。 研究的更广泛影响包括研究生和博士后研究人员直接参与任务，以及改善美国和墨西哥科学家和学生之间的合作。 研究结果将直接提交给加州和墨西哥政府官员，并将为制定空气质量管理战略提供信息，以减少对人类健康、生态系统和气候的不利影响。

The California-Mexico border region suffers from high levels of air pollution due to a large and expanding population, industrial growth, transportation and agriculture. In this project, researchers will investigate cross-border transport of pollutants and their impacts on regional air quality and climate through the collection and analysis of field data. The observational component of the work includes ground-based measurements along the California-Mexico border region, utilizing a combination of a central fixed site that will house state-of-the-science instruments to measure gases, aerosols, radiation and meteorological parameters and a mobile laboratory that can measure surface-atmosphere exchange fluxes using eddy covariance. The study will be complemented by measurements provided by Mexican colleagues at the fixed site and several mobile units for criteria pollutants and meteorological parameters. The main scientific objectives are to (1) characterize the emissions from major sources in the California-Mexico border regions, (2) determine the spatial and temporal variability in anthropogenic emissions of greenhouse gases and traditional air pollutants, and (3) elucidate the transport and transformation of these emissions and assess their impact on local and regional air quality and climate. A planned NOAA and California Air Resources Board study will provide additional data to aid in the analysis of these subjects.The Intellectual Merit of the project is to assess the sources and processing of particulate matter and its precursors in the border region and their effects on regional air quality and climate. The analysis tasks will much better define the interplay of emissions and secondary particle formation, the diurnal evolution of fine particulate matter chemical composition under degraded air quality conditions, atmospheric processing of aerosols, particularly soot-containing particles, and their transport and transformation. The Broader Impacts of the research include the direct involvement of graduate students and postdoctoral researchers in the tasks, and improved collaboration between U.S. and Mexican scientists and students. Results from the study will be directly presented to California and Mexican Government officials and will inform the development of air quality management strategies to reduce adverse human health, ecosystem, and climate impacts.