分子水平表征城市边界层大气有机气溶胶的垂直分布特征

项目名称： 分子水平表征城市边界层大气有机气溶胶的垂直分布特征

项目编号： No.41475117

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 傅平青

作者单位： 中国科学院大气物理研究所

项目金额： 120万元

中文摘要： 大气气溶胶的研究，尤其是有机气溶胶的分子组成、粒径分布以及稳定同位素组成的研究一直是国际大气化学领域的研究热点。在我国城市地区，对于灰霾和非灰霾时期的大气气溶胶的化学组成及来源解析等已有系统地阐述，然而对城市边界层中气溶胶化学组成的垂直分布特征研究相对匮乏。本课题拟利用中国科学院大气物理研究所的325米气象铁塔，对北京市区大气气溶胶的垂直分布特征等进行系统研究。采用稳定C和N同位素分析相结合，利用有机气溶胶的分子标志物浓度、同位素比值、初次和二次有机气溶胶标志物的比值、粒径分布，以及水溶性有机碳的荧光光谱特性等在边界层中的垂直分布特征，研究该地区大气气溶胶的来源、组成和老化过程、季节性变化规律等。目的是增进理解各种典型霾天气下，城市大气边界层的化学组分的垂直分布特征及其形成和演化机制，为区域城市大气环境保护和改善提供科学依据。

中文关键词： 大气气溶胶；二次有机气溶胶；稳定同位素比值；垂直分布；分子组成

英文摘要： Atmospheric aerosols are formed from a large variety of natural and anthropogenic sources. In recent years, studies that focus on the molecular composition and size distribution of organic aerosols, as well as stable isotope ratios of aerosol particles are among the most active research fields in atmospheric chemistry. Although exellent studies on the chemical composition and source apportionment of atmospheric aerosols have been conducted in urban regions in China, little is known about the vertical distributions of organic aerosols in the urban boundary layer, especially at a molecular level. In this project, the vertical distribution of organic aerosols will be investigated based on the meterological tower (325 m above ground level) at a urban site in Beijing. The organic molecular compositions, size distributions of different organic species as well as their mass concentration ratios will be characterized at a comprehensive way, together with their seasonal and vertical patterns. Fluorescenc properties of water soluble organic carbon (WSOC) and their vertical distributions will also be one of the main topics in this study. In general, the objective of this project is to broaden our knowledge of the vertical distributions of organic aerosols in the urban boundary layer and their sources, formation and aging processes during long-range transport, which provides useful scientific evidence to protect the atmospheric environment and improve the air quality in urban regions.

英文关键词： Atmospheric aerosols;Secondary organic aerosols;Stable isotope ratios;Vertical distribution;Molecular composition