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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.

该项目涉及开发一种用于测量对流层HONO浓度的激光光致碎裂/激光诱导荧光仪器。环境空气将膨胀到低压电池中，HONO将通过在355 nm处的光解被破碎成OH和NO。将使用气体膨胀荧光测定（FAGE）方法在308 nm处定量OH光片段。预计这一新仪器将联合收割机结合光谱技术的选择性和化学技术的低检测限，使其成为科学界的主要兴趣。这一新仪器将在实验室进行充分的特性鉴定，预计将在城市大气中进行初步的实地测量。HONO将被测量除了OH和NO，以确定是否未知来源的HONO发生在大气中的布卢明顿，IN。一个不完整的描述的主要来源的HONO在当前的大气化学模型可能有重要的影响，空气质量控制策略，因为它可能会导致低估的光化学污染物的浓度。例如，臭氧和二次有机气溶胶由于对人类健康的有害影响而受到社会的特别关注。此外，准确描述自由基的主要来源对气候变化问题很重要，因为大气氧化过程控制着温室气体和替代性氯氟烃的寿命，而这些气体和氯氟烃对地球的辐射收支有着重大影响。未来在实地活动中部署这一仪器以及在实验室研究中使用它将为大气中发生的HONO化学提供更多的见解，并将有助于改进大气化学的实际模型。今后将这一仪器与其他测量技术进行相互比较，也将有助于评估大气中HONO测量的准确性。