利用粒子测量系统PMS探测的气溶胶等资料,结合观测期间的天气实况和气团后向轨迹对2008年秋季河北中南部不同天气条件下的大气气溶胶空间分布特征进行了分析和研究.结果表明:不同天气背景下河北中南部气溶胶数浓度的垂直分布和气溶胶粒子谱分布特征存在显著差异.混合层高度,逆温层和相对湿度峰值引起的气溶胶累积效应,云层分布不均以及气溶胶来源特性差异对气溶胶的空间分布特征有着重要影响.不同天气条件下河北中南部近地面的气溶胶数浓度范围为904.4~3005.0个/cm3.近地面气溶胶数浓度阴天条件下最高,晴空条件下最低.气溶胶粒子谱分布特征与大气层结,逆温层,云区分布等密切相关.逆温层是导致粒子谱呈双峰或多峰分布的主要原因之一.由于云内气溶胶粒子吸湿增长,粒子谱峰值向大尺度方向偏移.云外的气溶胶粒子谱宽且比云内窄.受大气气溶胶粒子本身重力沉降作用的影响,高层粒子谱宽比低层窄,粒子谱峰值向小尺度方向偏移.%This study analysed the spatial distribution of atmospheric aerosol properties under different weather conditions over both central and southern regions of Hebei province in autumn 2008, based on in-situ observations of aerosols from the Particle Measurement System (PMS) along with the back trajectories from HYSPLIT model. It showed that there were significant differences in the vertical distribution of aerosol concentration and aerosol particle size distribution under different weather patterns. Various factors were found to have an impact on the spatial distribution of aerosol concentration, including the mixed-layer height, relative humidity, cloud distribution, and aerosol sources. The number concentration of aerosol ranged from 904.4 to 3005.0 cm-3 near the ground during the observation period. The maximum aerosol number concentration near the ground was found in a cloudy day, and the minimum in a clear day. The aerosol particle size distribution function (PDF) was greatly affected by atmospheric stability, inversion layer, and the distribution of cloud region. The aerosol PDF showed a bimodal or even multimodal pattern primarily due to the existence of inversion layer. The particle size value with the peak frequency shifted to a bigger value due to the hygroscopic growth of aerosol particles in clouds. The spectrum width of aerosol PDF was narrower outside than inside clouds. The aerosol PDF spectrum width was narrower with a smaller peak frequency particle size at high than low altitudes due to the effect of aerosol particle's gravitational settlement.
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