Development of a Laser Photofragmentation/ Laser-Induced Fluorescence Instrument for Tropospheric Measurements of Nitrous Acid

开发用于对流层亚硝酸测量的激光光碎裂/激光诱导荧光仪器

基本信息

批准号：
1012161
负责人：
Sebastien Dusanter
金额：
$ 39.32万
依托单位：
Indiana University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2010
资助国家：
美国
起止时间：
2010-09-01 至 2015-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1012161&HistoricalAwards=false
关键词：
Development Laser Photofragmentation Induced Fluorescence

项目摘要

This project involves the development of a Laser Photofragmentation/Laser Induced Fluorescence instrument for measuring tropospheric concentrations of HONO. Ambient air will be expanded into a low-pressure cell and HONO will be fragmented into OH and NO by photolysis at 355 nm. The OH photofragment will be quantified using the Fluorescent Assay by Gas Expansion (FAGE) approach at 308 nm. It is anticipated that this new instrument will combine the selectivity of spectroscopic techniques and the low detection limit observed for chemical techniques, making it of prime interest for the scientific community. This new instrument will be fully characterized in the laboratory and it is anticipated to perform initial field measurements in an urban atmosphere. HONO will be measured in addition to OH and NO to determine if unknown sources of HONO are occurring in the atmosphere of Bloomington, IN.An incomplete description of the major sources of HONO in current models of atmospheric chemistry may have important implications for air quality control strategies as it may lead to an underprediction of the concentrations of photochemical pollutants. For example, ozone and secondary organic aerosols are of particular interest to the society due to detrimental effects on human health. In addition, an accurate description of the main sources of free radicals is important to issues of climate change as atmospheric oxidation processes control the lifetime of greenhouse gases and the alternative chlorofluorocarbons, which have a significant impact on the radiative budget of earth. Future deployments of this instrument during field campaigns as well as its use during laboratory studies will provide additional insights in the HONO chemistry occurring in the atmosphere and will help improve actual models of atmospheric chemistry. Future intercomparisons of this instrument with other measurement techniques will also help in assessing the accuracy of HONO measurements in the atmosphere.

该项目涉及开发激光光碎片/激光诱导的荧光仪器，用于测量对流层的HONO浓度。环境空气将扩展到低压电池中，Hono将分散成OH，而在355 nm处的光解会散布。将使用308 nm的气体膨胀（FAGE）进近的荧光测定法对OH的光片段进行定量。预计该新仪器将结合光谱技术的选择性和对化学技术观察到的低检测极限，从而使科学界的主要兴趣。该新仪器将在实验室中充分表征，预计将在城市气氛中进行初始的现场测量。除了OH之外，还将衡量HONO，并且可以确定HONO的未知来源是否发生在Bloomington的大气中。例如，由于对人类健康的有害影响，臭氧和二级有机气溶胶特别感兴趣。此外，随着大气氧化过程控制温室气体的寿命和替代性的氯氟甲碳，对自由基的主要来源的准确描述对于气候变化的问题很重要，这对地球的辐射预算产生了重大影响。该工具在现场运动中的未来部署及其在实验室研究中的使用将提供大气中发生的Hono化学反应的其他见解，并有助于改善大气化学的实际模型。该工具与其他测量技术的未来截期也将有助于评估大气中Hono测量的准确性。