摘要
为了全面了解人工消雹对云中冰相粒子的浓度和时空变化以及冰雹云微物理过程和起放电的影响,本文利用包含了AgI催化方案的三维强风暴动力电耦合数值模式,以AgI播撒量为唯一变化量进行了多组模拟实验。结果表明,催化过后,整体上,-40~0℃范围内的冰晶、雪花和霰粒子数浓度和比含水量增多。播撒AgI使霰的平均尺度减小,向雹的转化比例大为降低,因此冰雹的比含水量和浓度都减小。随着AgI播撒剂量的增加,冰晶、雪花和霰粒子的数浓度和比含量整体变化趋势不变,增大与减小区域相对应,但变化更明显;消雹效果会更好,但降雨量呈先增加后减小。播撒AgI会使冰雹云前期正的非感应起电率区出现时间提前,中心增强,上界高度抬升,后期负的非感应起电率区中心增强。所以,播撒后前期主要使底部次正电荷区增强,后期主要使上方主正电荷区和中部负电荷区增强。随着催化剂量增多,这些变化越明显。播撒AgI对地闪有一定的抑制作用,而使云闪和总闪少量增多,首次放电和云闪的峰值时间提前,放电持续性更强,闪电频发时段的闪电频率略有降低。
A hail process in Xunyi hail suppression experimental area of Shaanxi Province at 13:00(Beijing Time)on 28 July 1997 was simulated by using a three-dimensional strong storm dynamic electric coupling numerical model.This paper analyzes the influence of artificial hail suppression on the concentration and temporal and spatial variation of ice particles in clouds,as well as its influence on electrification and discharge.The results show that,overall,the concentration and specific water content of ice crystals,snowflakes and graupel particles increase in the range of-40~0℃.AgI seeding reduces the average scale of graupel and greatly reduces the conversion ratio to hail,resulting in the reduction of specific water content and number concentration of hail.With the increase of AgI seeding dose,hail suppression effect will be better,but the rainfall will first increase and then decrease.Therefore,the seeding dose should take an appropriate value between balanced hail suppression and precipitation enhancement.AgI seeding will lead to the positive lower non-induced electrification zone appears earlier,the center is enhanced and the upper boundary is raised in the early stage,while in the late stage,the center of the negative upper non-induced electrification zone is enhanced.Therefore,the bottom sub-positive charge area was enhanced in the early stage after seeding,and the upper main positive charge area and the middle negative charge area were enhanced in the late stage.With the increase of catalytic dose,these changes became more obvious.AgI seeding has a certain inhibitory effect on ground lightning,but the cloud flash and total flash increase a little after seeding,the peak time of the first discharge and cloud flash is earlier,the discharge duration is stronger,and the lightning frequency is slightly reduced in the lightning frequent period.
作者
鲁鲜
郭凤霞
吴泽怡
刘舟
邓洁
陈可
王清源
LU Xian;GUO Fengxia;WU Zeyi;LIU Zhou;DENG Jie;CHEN Ke;WANG Qingyuan(Emergency Management College/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Scienceand Technology,Nanjing 210044.Jiangsu,China)
出处
《高原气象》
CSCD
北大核心
2024年第1期199-216,共18页
Plateau Meteorology
基金
国家重点研发计划项目(2017YFC1501503)
国家自然科学基金项目(41975003)
第二次青藏高原综合科学考察研究项目(2019QZKK0104)。
关键词
冰雹云
人工消雹
电荷结构
放电类型
雷暴云数值模拟
hail cloud
artificial hail suppression
charge structure
discharge type
numerical simulation of thunderstorm clouds
