| Using air-borne PMS data obtained in Hebei province during the autumn from 2005 to 2007,combined with weather data,the vertical and spectrum distributions of aerosol particles were analyzed in different weather and cities,as well as cloud microphysical structure in rainfall.First,the fine aerosol particles concentration near the ground was between 103～104 cm-3in the autumn of Shijiazhuang,and the coarse particle concentration was between 10-1～100 cm-3,the average diameter of fine particles and coarse particles was 0.15～0.21μm and 1.5～3.2μm respectively.Within 1～2 km,the number concentration of fine particles was between 102～103 cm-3,represented one order of magnitude to the ground,the average concentration of coarse particles was 10-2～10-1cm-3,diameters was between 0.13～0.23μm and 1.8～2.9μm.The aerosol pollution was very heavy in Handan at 800m,1200m,3000m,the number concentration was 2 times than Xingtai,Baoding and Shijiazhuang.Over the sea (Caofeidian),the fine and coarse aerosol particles concentration was 101～102cm-3,it was lower than the land over an order of magnitude.Second,particle concentration and average diameter generally decreases with the height;when inversion exist,the number of particles accumulated at the end of the inversion layer.Three,the distribution of diameters and concentration can be influenced badly by the relative humidity;when the humidity increased,the particle diameter increaser, the number of particles reduced.Four,the fine aerosol distribution in precipitation weather follows bimodal distribution;in sunny and cloudy weather,the fine size distribution follows unimodal distribution;rough aerosol was always with the unimodal distribution. Five,when the relative humidity was at 40 to 50 percent and the aerosol concentration was at 103～104cm-3at Sunny conditions,the concentrations of CCNwas higher which reaching 103cm-3;the CCN concentration over the Handan industrial areas greater than the air over the airport(Suburb)at S=0.5,it may be due to the reasons for industrial production caused by emissions of chemical emissions.Comprehensive analysis of cloud microphysical structure information,we can find some Features.First,the droplet number at the bottom of altostratus is greater than the upper, the number changes in the range of 10～120cm-3,diameters of 9.21μm.The average diameter was 8.19μm at the bottom,and 11.66μm in the top,the particle diameter increases with the height.The biggest liquid water content was 0.25 g/m3,average liquid water content was 0.025 g/m3 at the bottom.Second,cloud concentrations at the upper layer was higher than the bottom in cumulostratus,droplet number concentration changes in the range of 10～80 cm-3, diameters of 7.56μm,and with the increasing height the diameter increased first and then decreased.Average liquid water content was 0.0418g/m3,the biggest water content was 0.169 g/m3,it was higher than the bottom,and liquid water content reducd whth height.Three,when bimodal spectrum appears in the frontal zone cloud,is always accompanied by a widen of the cloud droplet spectrum,increased in the number of big cloud droplets,decreased in the number of small cloud droplets,cloud droplet spectrum narrowed and the disappearance of two peaks have some ups and downs of the relationship with the water content.Four,the correlation of the aerosol and cloud number drops under the cloud is 0.827,and adoptes the significant level of 0.05 for the t-test.There is a positive correlation between aerosol number concentration below the cloud base and cloud droplets number concentrations.
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