基于火箭和高炮真实催化轨迹的一次对流云消减雨的数值模拟  

Numerical Simulation of a Convective Cloud Rainfall Reduction Based on the Realistic Seeding Trajectories of Rocket and Artillery

作　　者：刘卫国[1,2] 史月琴[1,2] 党娟[1,2] 陶玥[1,2] 周毓荃[1,2] LIU Weiguo;SHI Yueqin;DANG Juan;TAO Yue;ZHOU Yuquan(Cloud–Precipitation Physics and Weather Modification Key Laboratory(CPML),China Meteorological Administration,Beijing 100081;Weather Modification Center,China Meteorological Administration(CMA),Beijing 100081)

机构地区：[1]中国气象局云降水物理与人工影响天气重点开放实验室,北京100081 [2]中国气象局人工影响天气中心,北京100081

出　　处：《大气科学》2023年第2期430-452,共23页Chinese Journal of Atmospheric Sciences

基　　金：国家重点研发计划项目2018YFC1507901,2016YFA0601701;中国气象局重点创新团队支持项目CMA2022ZD10;国家自然科学基金项目41075099。

摘　　要：效果评估仍是人工影响天气研究面临的困难问题,数值模式在催化效果的评估方面有望发挥更大作用,建立能够模拟真实催化过程的数值模式是一条可行的途径。本文对一套三维中尺度催化模式进行了改进,采用了新的碘化银核化计算方案,在模式中增加了人工冰晶预报量及相关微物理过程,并实现了对地面火箭和高炮作业方式的仿真模拟。使用改进后的模式,采用500 m的水平分辨率,模拟了2019年9月1日华北地区一次对流云系的人工消减雨作业过程,对催化作业的消减雨效果进行了数值评估,并对碘化银在对流云中的核化特征及其催化作用机制进行了分析。结果表明:(1)催化作业对目标云系的雷达回波强度产生了一些影响,催化导致较多降水粒子滞留在高空,使得云体上部的回波强度略有增加,云体中下部的回波强度减弱,但催化作业并未改变目标云系雷达回波的自然演变趋势。(2)催化作业达到了一定的消减雨效果,作业区下游出现大面积减雨区,降水总量减少,降水强度减弱,局地最大减雨量为0.27 mm,主要影响区的平均减雨率为5.1%。(3)碘化银催化剂主要的核化方式为凝结冻结核化,其次为接触冻结核化。(4)催化作业造成了过量播撒,人工冰晶的成长占据竞争优势,它抑制了过冷层中其他水成物的自然增长过程,人工冰晶的凝华增长是导致云中水汽和云水消耗量增加的主要原因,凝华潜热的释放最终也引起云中垂直气流发生变化。(5)冷云降水是此次降水的主要物理机制,受催化的影响,暖层中霰融化过程的减弱导致雨滴总质量减少,这是降水减弱的主要原因,落入暖层下部的雨滴数量减少则是降水减弱的另一原因。Effect evaluation remains a difficult issue to resolve in the weather modification field.Numerical models can play a huge role in the effect evaluation of cloud seeding.Thus,a developing numerical model with more realistic simulations of the cloud seeding process is a viable solution to this concern.A three-dimensional mesoscale seeding model was developed in this study by coupling it with a new AgI(silver iodide)nucleation calculation scheme.Artificial ice crystal predictand and its associated microphysical processes were introduced in the model,and the model can thus simulate realistic seeding operation modes of both ground-based rockets and artillery.The artificial rainfall reduction operation of a convective cloud system in North China on 1 September 2019,was simulated using this seeding model with a horizontal grid spacing of 500 m.Subsequently,the seeding effect of rainfall reduction operation was evaluated,as well as the nucleation characteristics and working mechanism of AgI agents in convective clouds were analyzed.The results revealed the following:(1)Cloud seeding impacted the radar echo intensity of the target cloud system.Furthermore,more precipitation particles remained in the upper cloud region because of the cloud seeding operation,slightly increasing the echo intensity of the upper region of the cloud body and weakening the echo intensity of the middle and lower portion of the cloud body.However,the natural evolution tendency of radar echoes of the target cloud system has not been altered by cloud seeding.(2)Moreover,cloud seeding achieved certain rainfall-reducing effects,and a large rainfall-reducing zone formed downstream of the operation area.The total rainfall decreased,and the rainfall intensity weakened.The greatest local value of rainfall amount reduction was 0.27 mm,and the rainfall in the main affected area decreased by 5.1%on average.(3)The AgI agent’s main nucleation mode was condensation-freezing nucleation,followed by contact-freezing nucleation.(4)Cloud seeding operations caused

关 键 词：中尺度催化模式 对流云消减雨 碘化银核化 人工冰晶 效果评估 催化作业仿真 

分 类 号：P481[天文地球—大气科学及气象学]