为研究华东高山地区云凝结核（Cloud Condensation Nuclei，CCN）沿山峰的垂直变化特征，2011年6月利用云凝结核计数器（Cloud Condensation Nuclei Counter，CCNC）在黄山三个不同高度处对CCN进行观测。观测结果表明，不同高度的CCN浓度随时间的变化趋势基本一致，CCN浓度随高度的升高而减小，过饱和度为0.8%时山顶、山腰、山底CCN浓度平均值分别为1105.62、1218.39和1777.78 cm-3，山底的高CCN浓度（大于1000 cm-3）出现频率大于山腰和山顶，表明山底受周边污染源的影响较山顶和山腰大。山顶和山底的日变化曲线均为双峰型，两个峰值分别出现在午前和午后，与大气边界层高度及山谷风变化有关。利用公式N=CSk拟合了山顶在不同天气条件下CCN活化谱，并分析了其变化特征。结果显示，晴天、雨天和雾天的C值分别为2798、384、765，小于一些污染城市，属于清洁大陆型核谱。本文结果有助于改进对华东背景地区云凝结核时空分布的认识，为该地区云雾核化在数值模式中的表达提供观测依据和参数化方案。
To investigate the vertical variability of cloud condensation nuclei (CCN) along mountain peaks in alpine regions of eastern China, the number concentration of CCN were obtained using a cloud condensation nuclei counter (CCNC) at three altitudes of Huangshan Mountains in June 2011. The results show that the time series of CCN concentration at these altitudes were nearly consistent and that the CCN concentration decreased with altitude. At a supersaturation level of 0.8%, the average CCN number concentrations were 1105.62 cm-3, 1218.39 cm-3, and 1777.78 cm-3 at the foot, mid-height and summit of the mountain, respectively. The occurrence frequency of a high CCN concentration of more than 1000 cm-3 recorded at the foot of the mountain is higher than that recorded at mid-height and the summit of the mountain. These results suggest that the environment at the foot of the mountain was influenced by the pollution sources in the surrounding areas which were heavier than those at mid-height and the summit. A bimodal pattern at both the summit and the foot of the mountain was presented in the diurnal variation. A peak appeared at forenoon and at afternoon, which is related to variation in the atmospheric boundary layer height and the valley wind. The fitted CCN spectra for various weather conditions at the summit of the mountain were obtained using the expressionN= CSk, and the properties were analyzed. The results show that the fitted spectra parameter C was 2798, 384, and 765 on sunny, rainy, and foggy days, respectively, which is lower than the results recorded in some polluted cities. The size distribution of the CCN is shown to be a clean continental type. The results of this study will be conducive to a better understanding of the temporal and spatial distributions of CCN, particularly for eastern China. In addition, the basis for observation and parameterization schemes will be improved for the presentation of cloud activation in numerical models over this region.
李力,银燕,顾雪松,陈魁,谭稳,杨磊,袁亮.黄山地区不同高度云凝结核的观测分析.大气科学,2014,38(3):410~420 LI Li, YIN Yan, GU Xuesong, CHEN Kui, TAN Wen, YANG Lei, YUAN Liang. Observational Study of Cloud Condensation Nuclei Properties at Various Altitudes of Huangshan Mountains. Chinese Journal of Atmospheric Sciences (in Chinese),2014,38(3):410~420复制