利用2012年9月至10月在黄山光明顶气象站使用自行搭建的新型静力真空水汽扩散云室,对大气冰核进行观测的资料分析。结果表明:在活化温度为-20℃、相对冰面过饱和度为8%的实验条件下,黄山山顶的大气冰核平均浓度为2.03个/L,最大浓度是最小浓度的5倍左右。不同活化温度下的冰核浓度具有一致的逐日变化特征;并且冰核浓度随时间的变化与较大气溶胶粒子浓度的变化相一致。冰核浓度在下午14:00时明显高于上午08:00,这可能是与太阳辐射的作用有关。冰核浓度随着活化温度的降低,呈现很好的指数式增加的趋势;并且发现在活化温度为-19℃左右时冰核浓度达1个/L。还建立了冰核浓度与活化温度及粒径大于0.5μm的气溶胶数浓度之间的参数化关系;并且发现加入气溶胶浓度后的参数化关系式相对于仅仅依赖于温度的参数化关系式要更为合理。冰核浓度随活化湿度的增加而增加;并且当水汽条件从冰面饱和增加到水面饱和时,冰核浓度会急剧增加。黄山山顶降水对大气冰核具有明显的清除作用。
The concentration of ice nuclei (IN) was measured and analyzed using the new type static vacuum water vapor diffusion chamber on the top of Mrs. Huangshan in southeast China. The results show that the mean concentration of IN was 2.03/L under the experimental conditions of the activation temperature of - 20℃ and the supersaturation respect to ice of 8%, and the maximum concentration was about 5 times of the minimum concentration. Under the different activation temperature, concentrations of ice nuclei had a consistent daily variation, and the change of IN concentrations with time was consistent with the change of the number concentration of the aerosol particles in size of 0.5 -20μm. The concentration of ice nuclei at 14:00 was significantly higher than at 08:00, which may be related to the role of solar radiation. A parametrization has been also established that dependent on both temperature and the number concentration of aerosol particles with the size larger than 0.5 Ixm. The concen- tration of IN increases with increasing supersaturation. The precipitation has a obvious removal effect on IN, by the removal of aerosol particles.