| Data of the airborne particle measurement system (PMS) on Cheyenne IIIA aircraft during2006-2010from Hebei weather modification office was analyzed in our study. We mainly focus on the researches of aerosol vertical distribution, distribution of cloud condescension nuclei (CCN) and cloud microphysical characteristics over the North China Plain (NCP).Airborne aerosol probe (PCASP-100X) data, combined with synoptic situation and the related meteorological parameters from the NCAR/NCEP daily reanalysis data, was used during our research. Seasonal variation of aerosols vertical distribution, aerosol scale height and aerosol size distribution is explored, together with meteorological parameter effects on aerosol vertical distribution. Wind speed has shown a negative correlation with surface aerosol number concentration, and precipitation plays a scavenging effect on aerosols. It is shown that boundary layer height and convective stability will further affect transportation of aerosol from the surface to a higher level. Three surface aerosol number concentration categories are found according to the analysis results, of which the concentration range was0～5×103cm-3,5×103～10×103cm-3,10×103～15×103cm-3, respectively. Significant difference of aerosol vertical distribution is found under different synoptic situations. Three categories are concluded from our results, which is a case showing exponential declining trend (ED), a case with a surface aerosol layer (SAL), and case with a boundary aerosol layer (BAL), respectively. Aerosol mean scale height is1.0km,1.6km and1.0km for spring, summer and autumn.In-situ aircraft measurements of cloud and CCN for7flights were conducted over the NCP. We conclude that the cloud liquid water content (LWC) has a less value with an average range from0.03g/m3to0.14g/m3. Peak value of CCN number concentration is shown to correspond to the valley value of cloud number concentration. Because of CCN activation to cloud droplets, significant decrease of CCN number concentration is found when in cloud regimes. CCN over Shijiazhuang area displays typical continental characteristics.,CCN data collected from CCN counter was analyzed to illustrate CCN vertical distribution above different underlying surface and under different synoptic situations, and also the CCN saturated spectrum at600m. A detailed picture of the CCN vertical distribution was obtained showing that the CCN number concentration is higher in Xingtai and Handan, downwind of Shijiazhuang, especially in Xingtai which is closer to Shijiazhuang. CCN number concentration over Shijiazhuang is6.15,4.08,2.69and3.39times larger than that over Caofeidian under the supersaturation of0.1%,0.3%,0.5%and1.0%, respectively. Under sunny, cloudy and hazy conditions over the Shijiazhuang area, the fitting parameter k of the CCN supersaturated spectrum is1.24,0.93and0.90respectively.Using data collected from airborne forward scattering spectral probe (FSSP-100-ER), we conduct analysis on microphysical characteristics of different cloud types over the Shijiazhuang area in NCP during2006-2010. Generally, the mean cloud droplet number concentration (Nc) rank in descending is, stratocumulus (Sc), cumulus (Cu), cumulonimbus (Cb), nimbostratus (Ns),stratus (St), altostratus (As) and altocumulus (Ac) respectively. In the general case, the scaling factor (β=Re/Rv) and the parameter k (k=Rv3/Re3)is1.231and0.566and can properly represent warm cloud effective radius parameterization in global climate models. The results highlight that the cloud relative dispersion (ε) and β is close to0.4and1.2respectively with increasing Nc. |
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