对流层夜间化学研究

Advances in Tropospheric Night-Time Chemistry

NO3自由基与N2O5是对流层夜间化学的关键物种。一方面NO3与O3等组分是夜间大气中的重要氧化剂,与它们的反应是生物排放挥发性有机物(VOCs)的主要汇;另一方面NO3与N2O5和雨滴或气溶胶颗粒物发生的异相反应则是大气中氮氧化合物NOx(NO,NO2)的主要清除过程,从而可以减轻对流层臭氧污染。研究它们的化学反应性质及对其进行实地测量,对深入理解大气氧化过程和全面了解区域乃至全球大气自净能力有重要意义。本文总结了近年来有关夜间化学的研究成果,介绍了以NO3和N2O5为中心的基本夜间化学过程、对流层中NO3与N2O5的源与汇以及外场测量技术的最新研究进展,并提出了尚待解决的一些问题。

The nitrate radical NO3 and N2O5 play key roles in the night-time chemistry of troposphere, The NO3 radicals oxidize volatile organic compounds （VOCs） origining from biogenic emission, which is the primary sink of biogenic VOCs. Besides, the heterogeneous reactions of NO3 and N2O5 in aerosol and rainwater are the main scavenging processes of NOx in atmosphere, alleviating the ozone pollution in troposphere. Consequently, the field measurement and chemical characteristics study are very significant to understand the atmospheric chemical processes and the self-cleaning capacity of the global troposphere comprehensively. The recent progress and achievements on night-time chemistry of NO3 and N2O5, the field measurements, chemical reactions, the sources and sinks are reviewed, and some problems to be solved in the future are put forward.