Collaborative Research: Nitrate (NO3) Induced Nighttime Air Chemistry

虽然通常通过白天的光解、水相和气溶胶吸附迅速去除，但活性NO3自由基在挥发性有机化合物（如生物烃（如萜烯、醇））的氧化中起着难以捉摸的作用，特别是在夜间，此外在将氮氧化物转化为硝酸（HNO3）方面也起着作用。来自内华达大学DRI和霍华德大学的研究人员将进行为期四周的实地测量活动，同时进行一系列分析和建模工作，以评估城市沙漠环境中的NO3自由基化学。假设在低湿度条件下，普遍存在于干旱地区，也受到城市NO2和O3来源的影响，比在更潮湿的环境中观察到的更确定的NO3及其损失过程的测量将是可行的。城市研究地点（内华达州里诺）的夜间和日间化学将通过一系列直接和间接的化学测量技术来评估NO3自由基预算。这些数据受到测量参数的限制，将用箱形模型进行分析，看看是否有可能解释已知或假设的硝酸盐自由基损失机制。

Although normally rapidly removed through daytime photolysis, aqueous phase and aerosol sorption, the reactive NO3 radical plays an elusive role in the oxidation of volatile organic compounds such as biogenic hydrocarbons (e.g. terpenes, alcohols) especially at night, and additionally in the conversion of NOx species to nitric acid (HNO3). Investigators from University of Nevada DRI and Howard University will conduct a four week field measurement campaign together with a series of analysis and modeling efforts to evaluate NO3 radical chemistry in an urban desert setting. It is hypothesized that in low humidity conditions, prevalent in arid regions also subject to urban sources of NO2 and O3, a more definitive measurement of NO3 and its loss processes than can be observed in more humid environments will be practicable. Both nighttime and daytime chemistry of the urban study site (Reno, NV) will be characterized by a range of direct and indirect chemical measurement techniques allowing the evaluation of NO3 radical budgets. The data, constrained by measured parameters, will be analyzed with box models to see if it is possible to account for known, or postulated, nitrate radical loss mechanisms.