中国地区二次有机气溶胶的时空分布特征和来源分析

二次有机气溶胶(SOA)由于其在大气污染、气候变化与人体健康方面的影响,是我国大气环境中一种重要的污染物.确定中国SOA分布规律以及产生来源是大气污染防治的前提.利用全球化学传输模型(Model for Ozone and Related Chemical Tracers,Version 4,MOZART4)并集成多相SOA参数化方案,模拟了中国地区SOA的时空分布,并按前体物分区域进行了来源分析.结果表明,受SOA前体物排放分布的影响,中国地区的SOA主要分布在东部和南部地区,并且夏季SOA产量是冬季产量的2.5倍.中国地区分布的SOA由人为源排放产生占55%,高于自然源(45%);并且境内排放贡献了我国SOA产量的77%,主要影响东部近地面大气的浓度分布.境外排放主要影响我国西部地区,尤其是对高空SOA分布影响显著.

Spatiotemporal Distribution and Source Attribution of SOA in China

Secondary organic aerosol (SOA) is an important pollutant due to its significant impact on atmospheric pollution, climate change and human health. Understanding the source and distribution of SOA is the prerequisite of air pollution control. This study utilized the global chemical transport model MOZART4 (Model for Ozone and Related Chemical Tracers, Version 4) coupled with the parameterizations of SOA multiphase formation, to simulate the spatial and temporal distribution of SOA in China, and analyzed the source contributions of SOA from the aspects of different precursors and regions. Our results indicate that the majority of SOA production happened over the east and the south China due to the availability of SOA precursors, with the summertime production a factor of 2.5 higher than that in winter. Anthropogenic emissions played a dominant role in SOA production, accounting for 55% of SOA source in China, with the rest from biogenic sources (45%). The domestic emissions contributed 77% of SOA production in China, mainly influencing the SOA concentration distribution near the surface of eastern China, especially over North China Plain. Foreign emissions mainly dominated the SOA abundance in western China, especially at higher altitudes mainly due to the rare domestic emission over these areas and the long-range transportation of SOA.