中国南北方不同高度大气冰核数浓度及核化机制对比研究

The researches on atmospheric ice nuclei are mainly concentrated in the northern regions of China currently, while the studies of atmospheric ice nuclei in the southern region of China are relatively few. And the comparative study of atmospheric ice nuclei between the south and north of China is even scarcer. But the differences of distribution and properties of atmospheric ice nuclei between the south and north of China lead to the distinction of artificial rainfall operation. The project is made observations as represented in atmospheric ice nuclei gradient observations of Huangshan and Shenyang, by building the international advanced atmospheric ice nuclei observation instruments, and using the Bigg type blend and diffusion cloud chamber, combined with other meteorological elements observation equipment. The different concentrations of atmospheric ice nuclei number concentration changing with different position, time, origin, size, total concentration, activation temperature, activation humidity, the weather background were observed on different heights of Huangshan and Shenyang in China. And the ratio of nuclear mechanism under different time and space conditions, under different nuclear particle conditions, under different atmospheric ice nuclei nuclear conditions, under different weather conditions are analyzed. Finally, based on the above observational results of studies on various aspects, the suitable atmospheric ice nuclei nucleation parameterization scheme of the south and north of China will be made, and the different nucleation mechanism and different attribute of atmospheric ice nuclei of the south and north of China will be known. Provide a theoretical basis for the study of changes in different artificial rain operations of the south and north of China.

目前中国对大气冰核的研究主要集中在北方地区，而对南方地区大气冰核的研究相对较少，对南北方地区大气冰核的对比研究就更为稀少。但南北方大气冰核的分布差异及属性差异，导致南北方人工增减雨作业有着明显的区别。本项目以黄山地区及沈阳地区大气冰核的梯度观测结果为代表，通过搭建国际先进的大气冰核观测仪器，并利用Bigg型混合云室和扩散云室，结合其它气象要素观测设备，对中国黄山及沈阳地区各自不同高度大气冰核数浓度随空间、时间、来源、粒径大小、总数浓度、活化温度、活化湿度、天气背景等的变化情况进行观测研究，并得出不同时空条件、不同粒子条件、不同核化条件、不同气象条件下大气冰核的核化机制。最后综合以上各方面观测研究结果，对中国南北方典型地区大气冰核的参数化方案分别拟合参数化公式，最终得出我国南北方地区大气冰核数浓度及核化机制的属性差异。从而对中国南北方地区不同的人工增减雨作业提供理论研究基础。

本研究利用新型大气冰核高压静电采样器和新型静力真空水汽扩散云室，并结合其他大气冰核及气象要素观测仪器，于黄山和沈阳不同高度上进行大气冰核及相关气象要素的连续观测，得出主要结论如下：. 黄山北京时间上午大气冰核数浓度平均为18.37个/升，沈阳相同条件下为34.78个/升。无论总核化机制、凝结冻结核化机制还是凝华核化机制，黄山和沈阳大气冰核数浓度随着高度的增加而减小,且黄山存在春季较高，秋季次之，夏季较低的规律，沈阳存在秋季较高，春季居中，夏季较低的规律。同时总核化机制条件下大气冰核数浓度的标准偏差最大，凝结冻结核化机制标准偏差居中，凝华核化机制标准偏差最小。. 随着活化温度的升高，黄山和沈阳不同核化机制下大气冰核数浓度均呈指数形式降低。随着活化湿度的增加，大气冰核数浓度逐渐增大。当相对水面不饱和，而相对冰面过饱和时，仅仅可以通过凝华核化作用形成冰晶，当达到或超过水面过饱和时，则凝结冻结核化机制开始作用，此时大气冰核数浓度明显增大。随着降水及云雾过程的进行，黄山和沈阳大气冰核数浓度逐渐减小；随着污染过程的加重，黄山和沈阳大气冰核数浓度逐渐增加，阴天过程对黄山和沈阳大气冰核数浓度的影响并不明显。. 利用前期研究成果，拟合出黄山总核化机制、凝结核化机制、凝华核化机制大气冰核数浓度的参数化公式。同样，拟合出沈阳总核化机制、凝结核化机制、凝华核化机制大气冰核数浓度的参数化公式。