摘要
为进一步认识不同高度大气冰核数浓度分布及变化特征,对2011年和2012年4—9月在沈阳及周边地区开展的大气冰核飞机观测进行分析。结果表明:在-15℃和-20℃温度条件下,沈阳近地面大气冰核数浓度范围为101—102L-1;云中不同高度层(1.5—4.5 km)云中的背景浓度分别小于2.0 L-1和10.0 L-1;辽沈地区地面和云中的大气冰核分布均具有较大的时空变异性,其最大与最小数浓度之差可达1—2个量级;在4.5 km以下,不同高度大气冰核数浓度自地面向上随高度的增加逐渐减少;其中未受人工催化影响的自然冰核数浓度的垂直分布与幂函数有较好的对应关系;在海拔高度3.1 km的云中观测到人工催化剂对冰核浓度的影响,人工播撒碘化银后冰核数浓度至少增加了一个数量级。以上冰核数浓度检测对应水面过饱和度为-1.0%～5.0%,成冰过程包括了凝华与凝结—冻结核化机制。
For better understanding the distribution and variation characteristics of atmospheric ice nuclei(IN)concentration at different altitudes,an aircraft observational experiment was carried out over Shenyang and its surrounding areas from April to September in 2011 and 2012.The analysis results show that the values of IN number concentration in the near-surface layer at Shenyang range from 101 to 102 L-1 in the range of air temperature between-15 and-20℃,and the background concentration of IN at different altitudes(1.5-4.5 km)in clouds are less than 2.0 L^-1 and 10.0 L^-1,respectively.The spatial distribution and temporal variation of atmospheric IN in the near-surface layer and in clouds over Liaoning and Shenyang areas have large variability,with 1-2 order of magnitude in the difference between the maximum and minimum concentrations.The IN number concentration decreases gradually with increasing height below 4.5 km.The vertical distribution of the number concentration of natural IN that has not been affected by artificial catalysis follows a power function well,while the IN number concentration increases by an order of magnitude at least observed in clouds at 3.1 km after distributing silver iodide as the artificial catalyst.The IN number concentration detection corresponds to a water-surface supersaturation of-1.0%to 5.0%,and the ice formation process includes the deposition and condensation-freezing nucleation mechanisms.
作者
周德平
苏航
耿树江
王扬锋
洪也
刘宁微
ZHOU De-ping;SU Hang;GENG Shu-jiang;WANG Yang-feng;HONG Ye;LIU Ning-wei(Institute of Atmospheric Environment,China Meteorological Administration,Shenyang 110166,China;Liaoning Meteorological Observatory,Shenyang 110166,China;Liaoning Weather Modification Office,Shenyang 110166,China)
出处
《气象与环境学报》
2018年第6期133-139,共7页
Journal of Meteorology and Environment
基金
国家自然科学基金项目(41505120
41440036和40975084)共同资助
关键词
大气冰核
飞机采样
静力扩散云室
人工增雨
Atmospheric ice nuclei
Aircraft sampling
Static diffusion cloud chamber
Artificial precipitation
