CAREER: Toward an Improved Understanding of the Sinks and Photochemical Sources of Nitrous Acid on Boundary Layer Surfaces

职业：加深对边界层表面亚硝酸的汇和光化学源的了解

• 批准号: 1352375
• 负责人: Jonathan Raff
• 金额: $ 64.96万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-15 至 2024-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1352375&HistoricalAwards=false
• 关键词: CAREER; Toward; Improved; Understanding; Sinks

This research is focused on the investigation of selected urban and soil surfaces for their potential to serve as sources and/or sinks of nitrous acid to/from the atmosphere. Nitrous acid is an especially important compound in atmospheric chemistry because of its ability to serve as a precursor to the formation of the hydroxyl radical and thereby influence the oxidizing capacity of the atmosphere. Current chemical models are unable to reproduce the observed profiles of atmospheric nitrous acid, due in part to the fact that its sources and sinks are not well understood. Recent studies suggest that significant daytime production of nitrous acid may be attributed to heterogeneous reactions on various environmental surfaces, such as asphalt, cement, and soils. Laboratory studies will be conducted to generate the kinetics and photochemical data needed to advance predictive models of ambient nitrous acid (HONO) levels. This research will determine the reaction probabilities for (a) the uptake of HONO on soil, asphalt, and cement; and (b) nitrogen dioxide (NO2) conversion to HONO on iron oxides and asphalt under atmospheric conditions. Measured uptake coefficients will help to constrain the fraction of HONO that may be loss to boundary layer surfaces. The quantum yields of HONO formation and molar absorptivity values measured for nitrate adsorbed to surfaces (such as soil) are key parameters that will enable calculations of HONO fluxes from these sources.

这项研究的重点是研究选定的城市和土壤表面的研究，以便将其充当氮酸来源和/或从大气中/或从大气中进行。亚硝酸是大气化学中特别重要的化合物，因为它能够作为形成羟基自由基的先驱，从而影响大气的氧化能力。当前的化学模型无法重现大气一硝酸的观察到的曲线，部分原因是其来源和水槽尚不清楚。最近的研究表明，白天生产一硝酸可能归因于各种环境表面（例如沥青，水泥和土壤）的异质反应。将进行实验室研究，以生成推进环境一酸（HONO）水平的预测模型所需的动力学和光化学数据。这项研究将确定（a）Hono对土壤，沥青和水泥的摄取的反应概率； （b）在大气条件下，二氧化氮（NO2）在铁氧化铁和沥青上转化为Hono。测得的摄取系数将有助于限制HONO的比例，这可能是边界层表面的损失。 HONO形成的量子产率和为硝酸盐吸附到表面的硝酸盐（例如土壤）的摩尔吸收性值是关键参数，可以从这些来源计算HONO通量。