珠三角地区日最大混合层高度及其对区域空气质量的影响  

Daily maximum mixing height and its effects on air quality in the Pearl River Delta region

作　　者：廖志恒[1] 许欣祺 谢洁岚 周学思 范绍佳[1,2] LIAO Zhi-heng;XU Xin-qi;XIE Jie-lan;ZHOU Xue-si;FAN Shao-jia(School of Atmospheric Sciences,Sun Yat-sen University,Guangzhou 510275,China;Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies,Sun Yat-sen University,Guangzhou 510275,China)

机构地区：[1]中山大学大气科学学院,广东广州510275 [2]广东省气候变化与自然灾害研究重点实验室,广东广州510275

出　　处：《气象与环境学报》2019年第5期85-92,共8页Journal of Meteorology and Environment

基　　金：国家重点研发计划课题(2017YFC0209606、2016YFC0203305);国家自然科学基金重点项目(41630422)共同资助

摘　　要：大气混合层高度是影响大气扩散的主要因子之一,其对空气质量评估与污染物的存储量及分布起着重要作用。利用2014年4月至2018年3月珠三角地区香港(沿海站点)和清远(内陆站点)气象探空数据,采用干绝热曲线法估算代表大气垂直方向上大气混合能力的最大混合层高度,探讨沿海与内陆地区混合层高度的差异性,并将最大混合层高度估算值与地面观测的污染物浓度进行相关性分析。结果表明:珠三角沿海与内陆地区的混合层变化具有典型局地特征,沿海日最大混合层高度普遍低于内陆,两地平均高度分别为982m和1198m。区域混合层高度的空间差异性由多方面原因造成,其中温度日较差起到关键作用。由于海洋水体的气温调节作用,沿海地区温度日较差较小,因此混合层发展相对较低。珠三角地区各污染物浓度与混合层高度的相关性有较大差异,其中以CO为代表的一次污染物与混合层高度间呈显著负相关,以O3为代表的二次污染物与混合层高度间则呈显著正相关,而颗粒物作为多源性污染物(既有一次排放,又有二次生成),其与混合层高度之间的相关性较弱。Atmospheric mixing height is one of the main factors affecting vertical diffusion and plays an important role in the assessment of air quality and the storage and distribution of air pollutants.Based on 4-year(from April 2014 to March 2018)radiosonde measurements at Hong Kong(coastal)and Qingyuan(inland)stations,this study employs the dry adiabatic curve method to estimate the daily maximum mixing height(MMH)in the Pearl River Delta(PRD)region,then discusses the spatial differences of the MMHs in the coastal and inland areas,and finally analyzes the effects of the MMH on regional air pollution.The results show that the atmospheric mixing height has typical local characteristics.Specifically,the MMH in the coastal area is lower than that in the inland area and their average values are 982 m and 1198 m,respectively.The spatial differences of the MMH in the PRD region can be jointly explained by many factors,among which temperature diurnal range plays the most important role.The coastal area features a relatively smaller temperature diurnal range due to the modulation of seawater on air temperature,so the atmospheric mixed layer is relatively lower.Besides,there are great distinctions in the correlation between the air pollutants and the MMH in the PRD region.The primary pollutants(e.g.,CO)are negatively correlated with the MMH,while the secondary pollutants(e.g.,O3)are positively correlated with the MMH.In contrast,atmospheric particulate matters(e.g.,PM2.5)are weakly correlated with the MMH likely due to the complexity of their sources(including primary emission and secondary formation).

关 键 词：最大混合层高度 空气污染 差异性 相关性 

分 类 号：X831[环境科学与工程—环境工程] P468[天文地球—大气科学及气象学]