南京北郊冬季大气气溶胶及其湿清除特征研究

利用WPS(宽范围颗粒粒径谱仪)、雨滴潜仪和雾滴谱仪测量了2007～2008年冬季南京北郊大气气溶胶数浓度谱分布和降水强度,分析了气溶胶粒子的分布特征以及气溶胶粒径与湿清除系数的关系.结果表明:气溶胶粒子具有明显的双峰型R变化特征,数浓度主要集中在0.02～O.2μm粒径范围内,受汽车尾气排放、混合层高度变化以及颗粒物水平输送的影响较大.降雨、降雪和雾过程都对气溶胶粒子有不同程度的清除,降雨和浓雾对核模态和粗模态的气溶胶粒子的清除能力显著,降雪对粒径小于0.03μm的气溶胶粒子的清除能力较强.

Size Distributions and Wet Scavening Properties of Winter Aerosol Particles in North Suburb of Nanjing

Mcasurements of aerosol particle number concentrations and precipitation intensity during the winter of 2007-2008 were made by Wide-Range Particle Spectrometer(WPS),disdrometer(OTT Parsivel)and fog monitor (FM-100),in the north suburb of Nanjing.The size distribution characteristics of particles and the relationships be-tween particle size and scavenging coefficients were studied.With a bimodal distribution of diurnal variation,the aerosol particle number concentration,which is much affected by vehicle emission,change of boundary layer height,and the advection of particles,mostly falls between 0.02 and 0.2μm Rainfall,snowfall,and fog have different scavenging efficiency on particles.Aitken mode and coarse mode particles are more efficiently scavenged by rainfall and dense fog.Snowfall is efficient in the scavenging of particles smaller than 0.03 m.