The Role of Radical-Water Complexes in the Atmosphere

本项目将研究大气水汽对有机硝酸盐和二次有机气溶胶形成的影响。HOCH 2CH 2 O2（HEP，2-羟乙基过氧）+ NO作为温度和水蒸气的函数的反应的产物分支比的测量预测表明，高浓度的大气水蒸气可以导致有机硝酸盐的形成增加。此外，这项研究将调查的潜力，在一定条件下，过氧化氢自由基（HO 2）在水蒸气的存在下可以形成复合物，成为成核种子形成二次气溶胶。结果将连接的过氧自由基（HO 2和RO 2）的气相化学与二次气溶胶的形成作为水蒸气浓度，初始自由基浓度，温度和反应时间的函数。大气中的高水平的水蒸气可能对有机硝酸盐和二次有机气溶胶的形成（从气体到粒子的转换）有重要的影响。大气中的有机硝酸盐相对不活泼，可以提供一种将污染物从一个地区远距离迁移到另一个地区的机制。了解和量化二次有机气溶胶的形成对于预测其对气候变化的直接和间接影响至关重要。

This project will investigate the effects of atmospheric water vapor on the formation of organic nitrates and secondary organic aerosol. Measurements of the product branching ratio for the reaction HOCH2CH2O2 (HEP, 2-hydroxyethyl peroxy) + NO as a function of temperature and water vapor are predicted to show that high concentrations of atmospheric water vapor can lead to the increased formation of organic nitrates. Additionally, this research will investigate the potential that under certain conditions, hydroperoxyl radicals (HO2) in the presence of water vapor can form complexes that become nucleating seeds for the formation of secondary aerosols. The results will connect the gas phase chemistry of peroxy radicals (HO2 and RO2) with the formation of secondary aerosol as a function of water vapor concentration, initial radical concentration, temperature, and reaction time.High levels of water vapor in the atmosphere may have an important effect on the formation of organic nitrates and secondary organic aerosol (from gas-to-particle transformations). Organic nitrates in the atmosphere are relatively inert and can provide a mechanism for long-range transport of pollution from one region to another. Understanding and quantifying the formation of secondary organic aerosol is critical for predicting their direct and indirect effects on climate change.