Collaborative Research: Nitrate (NO3) Induced Nighttime Air Chemistry

虽然通常通过白天的光解、水相和气溶胶吸附快速去除，但活性NO3自由基在挥发性有机化合物(如生物碳氢化合物(如萜类、醇)的氧化中，特别是在夜间，以及NOx物种转化为硝酸(HNO3)的过程中发挥着难以捉摸的作用。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现场测量活动，并进行一系列分析和建模工作，以评估城市沙漠环境中的第三种自由基化学。据推测，在干旱地区普遍存在的低湿度条件下，与在更潮湿的环境中观察到的相比，更明确地测量NO2和O3源将是可行的。城市研究地点(内华达州雷诺)的夜间和日间化学都将以一系列直接和间接化学测量技术为特征，从而能够评估N3自由基预算。这些数据受测量参数的约束，将用盒子模型进行分析，以确定是否有可能解释已知的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 additionally subject to strong urban sources of NO2 and O3, a more definitive measurement of NO3 and its loss processes will be practicable than can be observed in more humid environments. 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.