摘要
对近年来中国重霾污染过程的气象成因的相关研究进行了总结,从大气环流背景、边界层流场以及气象因子等方面进行综合分析,并介绍了相关区域输送对污染的影响贡献,得出关于中国重霾过程污染气象的一致结论:冬季重霾发生的典型天气条件为高空500 h Pa西风纬向环流指数高,南北气流交换不畅,利于中国中东部高空稳定形势的发展,对应近地弱高低压系统,均压场控制频繁,稳定的大气层结使污染物更易在近地累积,偏南暖湿气流则促使大量二次污染物生成;副热带高压与青藏高原高压、西风带高压并合的形势,是引起中国夏季大气环境质量恶化的主要原因;台风引起的下沉逆温稳定天气,易造成珠三角地区重霾污染。区域和局地山脉气流辐合效应使污染物较易在山麓地带聚积,海陆风和山谷风带动局地污染物的垂直输送和区域间输送。地面弱风速、风向以及高湿度是影响大气质量的直接关键因子,混合层高度与空气质量具有较强的相关性,对限制污染物的垂向有效扩散产生重要影响。数值模拟气象要素对空气质量影响贡献得到多次验证,霾预警开始发挥重要作用,区域污染的输送作用对重点城市空气质量的影响不容忽视。在重霾过程污染气象的研究还有待深化的方面包括:重视模拟研究,对污染物在大气中多尺度传输、沉降及化学循环等全周期的行为轨迹进行追踪定量,制定有针对性的污染控制技术与对策;开展大气污染的影响边界研究,辅助气象预报为特定区域空气质量保障提出即时有效的防控措施和预警方案,为提高污染控制措施的有效性奠定科学基础。
Recent research findings of meteorological effects on heavy haze pollution in China are summarized in this study. This review is focused on influence of atmospheric circulation, convective boundary layer and other meteorological factors on regional haze, and on source contributions from regional transport of air pollutants. Consistent results have been found regarding the correlation between heavy haze and the meteorological factors. In winter, the high level of 500 hPa westerly zonal circulation index and weak air exchange between northern and southern China causing stagnant atmospheric condition in middle eastern China, which corresponds to weak and uniform atmospheric pressure field on the surface layer and stable atmospheric stratification with weak vertical air exchange, making accumulation of ground air pollutants. In addition, the relatively humid air coming from south fosters large amount of secondary organic aerosol formations that also contributes to heavy haze pollution in the northeast plain. In summer, the convergence of subtropical high pressure, Tibetan plateau high pressure and westerly high pressure deteriorates air quality in China. Typically, the typhoon-caused low convective boundary layer stagnant weather leads to heavy haze pollution in the pearl delta region. The mixed effects of regional and local mountainous air-flow make air pollutants accumulate in the mountainous areas, and the land-sea and mountain-valley breezes cause air pollutants to transport both horizontally and vertically. Wind speed, wind direction and humidity are the key meteorological factors that affect air quality. Since the mixed layer height restricts the effective vertical diffusion of air pollutants, strong correlation between the mixed layer height and air quality are found. Based on the air quality modeling research findings, the meteorology has significant effects on air quality, the air quality forecasting system becomes more and more important, and the effects of source contributions from regional transport of air pollutants should not be ignored on air quality in the Chinese megacities. Future research on air pollution meteorology should include performing multi-scale atmospheric modeling to quantitatively simulate the fate and transport of air pollutants in different atmospheric processes for air pollution control strategies and air quality decision making; studying the effects of convective boundary layer on air quality, building air quality forecasting system to develop more targeted countermeasures of air pollution control and early warning plans according to the meteorological conditions, and establishing scientific basis for improving the effectiveness of air pollution control strategies to alleviate heavy haze pollution.
出处
《生态环境学报》
CSCD
北大核心
2015年第11期1917-1922,共6页
Ecology and Environmental Sciences
基金
国家环境保护公益科研专项(201309062)
关键词
重霾过程
污染气象
环流背景
气流辐合区
heavy haze pollution
air pollution meteorology
atmospheric circulation
wind convergence zone