北京地区不同类型降水对气溶胶粒子的影响  

Effects of different types of precipitation on aerosol particles in Beijing

作　　者：吴进 孙兆彬[1] 翟亮[3] 李琛 

机构地区：[1]中国气象局北京城市气象研究所,北京100081 [2]京津冀环境气象预报预警中心,北京100081 [3]北京市气象台,北京100089 [4]北京市气象服务中心,北京100089

出　　处：《中国环境科学》2018年第3期812-821,共10页China Environmental Science

基　　金：北京市自然科学基金资助项目(8161004;8172051);北京市科技计划课题(Z151100002115045);国家自然科学基金青年项目(41605110);中央级公益性科研院所基本科研业务费专项(IUMKY201724)

摘　　要：利用2013~2015年大气成分与气象观测资料,分析了北京地区不同类型降水对气溶胶粒子的影响,结果表明:随着降水强度增大,PM_(10)、PM_(2.5)、PM_1浓度下降的时次比例、浓度下降比例均增大,PM_(10)下降幅度大于PM_(2.5)和PM_1;不同类型降水对气溶胶浓度影响不同,对流性降水中大气运动剧烈,对3种颗粒物都有快速而显著的清除效果;稳定性降水细分为3类,显著冷空气型的冷空气垂直下沉运动和降水湿清除可使粒子浓度缓慢下降,无显著冷空气但有颗粒物传输型的降水过程对气溶胶粒子的湿沉降效果有限,无显著冷空气无传输型气溶胶粒子吸湿增长可能导致粒子浓度不会下降;降雪或雨夹雪过程中随着降雪强度增大,气溶胶粒子浓度下降比例增大,但下降时次比例呈指数或者对数变化.雨雪相态转换的降水过程更为复杂,除了上述因素之外,还需考虑雨雪相态转变带来的水滴(雪)粒径、降水粒子对周边气流的动力拖曳作用的变化、冷空气下沉运动对流型的改变.Based on the environmental and meteorological data during 2013~2015, the influence of different types ofprecipitation on aerosol particles was analyzed. The results showed that with the increasing rainfall precipitation, theconcentration decrease ratio and mean of PM10, PM2.5, PM1 increased. PM10 declined more than PM2.5 and PM1.Different types of precipitation leaded to different effect on aerosol concentration. To the convective precipitation,atmospheric motion was fierce, which had a rapid and significant effect on scavenging of particles with differentdiameters. Stable rainfall was subdivided into three categories. To significant cold air type, the descending motion andwet scavenging may make particles concentration decreased slowly. To no-significant cold air and transmission type,the wet scavenging of stability weak precipitation could be neglected. To no-significant cold air and no-transmissiontype, rapid air humidification which made aerosol particle hygroscopic growth may lead to the concentration ofparticles not decreased. In snow or sleet process, with snowfall intensity increased, aerosol particle concentrationdecreased ratio increased.The ratio of the decrease was exponential and logarithmic. The precipitation process withsnow and snow phase transition was more complicated. Besides the above factors, it was necessary to consider theinfluence of the change of the water droplet （snow） size caused by the change of snow phase phase, the dynamic dragaction of precipitation particles on the surrounding air, the cold air subsidence movement and the change of flowsituation type.

关 键 词：对流性和稳定性降水 降雪或雨夹雪 大气运动 湿清除 气溶胶 粒径 

分 类 号：X513[环境科学与工程—环境工程]