Optical instrumentation to understand the chemistry of the atmospheric chlorine budget

对氧化化学的全面了解对于我们管理烟雾形成、气候变化和污染物长途运输等环境问题的能力至关重要。氯原子最近被认为是全球大气氧化的重要因素。然而，我们对氯原子形成的化学认识还不够充分。通过对假设参与氯原子形成的重要物种进行完整的研究，我们可以更好地理解和预测化学形成过程的重要性。这项研究的拟议设备是最先进的光学仪器，用于原位测量关键物种盐酸、氮氧化物和臭氧。盐酸将使用腔衰荡光谱进行测量，这将是加拿大第一个应用于大气测量的此类仪器。氮氧化物和臭氧将分别使用化学发光法和吸收法进行测量。所要求的仪器将与现有的基础设施一起使用，以提供研究这种化学所需的全套测量。最初，这些仪器将同时部署在圣约翰、纽芬兰和拉布拉多受污染的海洋边界层中，位于现有的城市采样点。这一地点为研究这些过程提供了理想的地点，因为它拥有丰富的氯源(包括海雾和道路盐)，以及已知的将非活性氯激活为活性氯的人为污染。拟议的测量将是第一次全面削减氯预算，包括对所有颗粒大小的颗粒氯的测量，以及气相盐酸的测量。在其他地点的后续实地工作和实验室流动管研究将使我们能够充分解决这一重要系统的化学问题，以便扩大规模，纳入全球模型。如果没有所需的设备，对我的研究计划至关重要的这个重要系统的化学成分就无法研究。这项工作预计将吸引高素质的人员，并有助于培训。所有参与这项工作的人员将在现场工作、仪器维护、仪器分析和大数据集分析方面获得极具市场价值的技能。

A complete understanding of oxidation chemistry is essential to our ability to manage environmental issues such as smog formation, climate change, and contaminant long-range transport. Chlorine atoms have recently been recognized as important to atmospheric oxidation globally. However, our understanding of the chemistry of chlorine atom formation is inadequate. By undertaking a complete study of the important species hypothesized to be involved in chlorine atom formation, we can better understand and predict the importance of chemical formation processes. The proposed equipment for this research is state-of-the-science optical instrumentation for in situ measurements of key species hydrochloric acid, nitrogen oxides, and ozone. Hydrochloric acid will be measured using a cavity ring-down spectroscopy and will be the first instrument of its kind applied to atmospheric measurements in Canada. Nitrogen oxides and ozone will be measured using chemiluminescence and absorption, respectively. The requested instrumentation will be used along with existing infrastructure to provide the complete set of measurements required to study this chemistry. Initially, these instruments will be deployed simultaneously in the polluted marine boundary layer of St. John’s, Newfoundland and Labrador at an existing urban sampling site. This location provides the ideal location for study of these processes, as it is rich in chloride sources (including sea spray and road salt), and the anthropogenic pollution known to activate unreactive chloride into reactive chlorine. The proposed measurements will be the first to close the chlorine budget comprehensively, by including measurements of particulate chloride in all particle sizes, along with gas-phase hydrochloric acid. Follow-up field work in other locations and laboratory flow tube studies will allow us to fully address the chemistry of this important system to scale-up for inclusion in global models. Without the requested equipment, the chemistry of this important system that is central to my research program cannot be studied. This work is expected to attract highly qualified personnel and to contribute to training. All personnel involved in this work will gain highly marketable skills in field work, instrument maintenance, instrumental analysis, and analysis of large data sets.