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.

这项研究的重点是调查选定的城市和土壤表面的潜力，作为源和/或汇的亚硝酸到/从大气中。亚硝酸是大气化学中一种特别重要的化合物，因为它能够作为羟基自由基形成的前体，从而影响大气的氧化能力。目前的化学模型无法再现观测到的大气亚硝酸的概况，部分原因是对其源和汇的了解不够。最近的研究表明，白天大量产生的亚硝酸可能归因于各种环境表面（如沥青、水泥和土壤）上的非均相反应。将进行实验室研究，以生成推进环境亚硝酸（HONO）水平预测模型所需的动力学和光化学数据。本研究将确定（a）HONO在土壤、沥青和水泥上的吸收;以及（B）大气条件下二氧化氮（NO2）在氧化铁和沥青上转化为HONO的反应概率。测量的吸收系数将有助于限制可能损失到边界层表面的部分HONO。HONO形成的量子产率和测量的硝酸盐吸附到表面（如土壤）的摩尔吸光系数值是关键参数，这将使计算HONO通量从这些来源。