气溶胶的云滴活化能力影响云的微物理特性,还表征气溶胶吸湿性的强弱。活化气溶胶(即云凝结核,Cloud Condensation Nuclei,CCN)的观测研究中的重要方法是CCN计数器(CCN Counter,CCNC)的应用。针对CCNC观测的影响因子进行了实验室研究。实验结果表明,CCNC所处的气压和设置的流量会对过饱和比产生等比例的影响,而进气温度可能导致非线性的影响。实验中发现当气压差超过300 h Pa时,CCNC气压调节装置会导致气溶胶的损失,且损失的比例随着压差的增大而增大。在气溶胶浓度超过10000个/cm3、过饱和比低于0.2%时,会出现对CCN数浓度的低估,可能是由于水汽消耗导致CCN无法全部活化而不能被CCNC观测。研究结果及给出的建议对CCN的观测有指导意义,同时有利于CCN数据的质量控制和分析工作。
【英文摘要】
Aerosol activity of forming cloud droplets affects cloud micro-physics and indicates aerosol hygroscopicity. Application of the cloud condensation nuclei(CCN) counter(CCNC) is an important method for studying CCN-active particles. Factors impacting measurements using CCNC are analyzed by laboratory study. In CCNC, variations of supre-saturations(SS) are found to be proportional to variations of the pressure and the flow-rate. Temperature conditions, under which CCNC is working, exhibit nonlinear influnces o...