大气硝酸盐气溶胶的光化学及其对大气灰霾和臭氧污染形成的影响

近年来我国大气污染事件频发，高浓度O3和细粒子污染成为严重环境问题，作为气溶胶重要组份的硝酸盐污染日益加重，高硝酸盐污染的灰霾事件日益显现。硝酸盐气溶胶在大气环境、气候变化和大气化学方面的重要性日渐突出，但目前对硝酸盐气溶胶在各种大气光化学过程中的作用认识不足。本项目拟用红外光谱、流动管反应器和外场观测设备等开展大气硝酸盐气溶胶的光化学及其对大气灰霾和臭氧污染形成的影响研究。通过考察硝酸盐在各种大气光化学过程中作用，阐明硝酸盐光化学对大气二次无机和有机气溶胶、O3和界/表面VOCs等形成过程、大气光敏化非均相反应过程和大气粒子光化学老化过程等的影响，以及这种影响对其他物种大气转化的进一步影响等，揭示大气硝酸盐光化学对大气灰霾和臭氧污染形成的影响。此研究可丰富对大气硝酸盐气溶胶认识，有助于澄清大气污染事件中高浓度气溶胶和O3形成和共存机制，有助于为我国大气污染控制和决策制定提供重要科学依据。

In recent years in China, photochemical pollution and haze episodes have occurred more frequently. High levels of ozone and atmospheric fine particles have become serious environmental problems. As a major component of atmospheric aerosol particles, nitrate aerosol pollution shows an increasing trend, and the haze episodes with high nitrate level is also increasingly apparent. The importance of nitrate aerosols is becoming increasingly prominent in atmospheric environment, climate change and atmospheric chemistry. However, the role of nitrate aerosol in various atmospheric photochemical processes is not well understood up to now. Here we study the photochemistry of atmospheric nitrate aerosol and its impacts on the formation of atmospheric haze and ozone pollution by using various measurement techniques and monitoring instruments such as infrared spectroscopy, flow tube reactor and field equipments. Based on the investigations on the roles of nitrate aerosol in various atmospheric photochemical processes, we will illuminate the impacts of nitrate aerosol photochemistry on the formation of VOCs in various atmospheric interfaces/surfaces, ozone and secondary inorganic and organic aerosols, the atmospheric photosensitized heterogeneous processes and the photochemical aging processes of atmospheric particles, explore the influence mechanisms, potential conversion pathways, and its further influences on the conversions of other atmospheric species, and finally reveal the impacts of photochemistry of atmospheric nitrate aerosol on the formation of atmospheric haze and ozone pollution. This study not only enrich the understanding of atmospheric nitrate aerosol, but also helps to clarify the formation and coexistence mechanisms of high concentrations of aerosols and ozone in air pollution events. This study also provides important information for the government to formulate air pollution control strategy and policy.