| 建筑物群中多上行先导三维模型的建立 |
| |
| 引用本文： | 余骏皓,谭涌波,郑天雪,王艺儒,师正.建筑物群中多上行先导三维模型的建立[J].应用气象学报,2020,31(6):740-748. |
| |
| 作者姓名： | 余骏皓 谭涌波 郑天雪 王艺儒 师正 |
| |
| 作者单位： | 1.南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心/中国气象局气溶胶与云降水重点开放实验室, 南京 210044 |
| |
| 摘 要： | 为实现对地闪过程中多上行先导现象的模拟，在已有三维随机放电参数化方案基础上，植入多先导始发与发展模块以建立高建筑群多上行先导模型，利用电场并行计算技术提高模拟效率。将新模型应用于实际地闪模拟并就统计数据与先导形态特征同观测数据进行对比。结果表明:上行未连接先导长度为12~709 m，起始高度为360~600 m，距连接点水平距离为255~1026 m，距下行先导最近分支的距离为326~589 m，与观测统计结果具有较高的一致性；形态上再现了实际地闪个例F1215中上行未连接先导始发时间早，通道笔直的特点，也能够模拟下行先导与单上行先导头部、单上行先导侧面、多上行先导中连接先导头部、多上行先导中连接先导侧面4种已有观测记录的连接情况，为后续研究提供基础模型。分析模拟结果初步得出结论:最高的广州塔能够对附近一定范围建筑起保护作用且能吸引较远处的下行先导分支；多先导的始发与最后一跳的连接受地面高建筑物群分布、高度以及下行先导位置综合影响。
|
| 关 键 词： | 数值模拟 连接过程 多上行先导 |
| 收稿时间： | 2020-05-12 |
A Three-dimensional Model Establishment of Multiple Connecting Leaders Initiated from Tall Structures |
| |
| Abstract: | A new model for simulating multiple upward leaders initiated from tall structures in cloud-to-ground (CG) lightning flash is established, in which the initiation and development module of are implanted in the existing 3D stochastic parameterization of leader attachment process, using electric field parallel computing technology to improve the simulation efficiency. The new model is applied to simulate real CG lightning and is compared with observation results of statistical data and leader morphological characteristics. Several model output parameters include the length of upward unconnected leaders (UULs), the inception height of UULs, horizontal distance between the strike point and the UUL's inception point, 3D distance between the nearest tip of the downward leader branches and the UUL's inception point when the UUL is initiated. Values range from 12 m to 709 m, 360 m to 600 m, 255 m to 1026 m, 326 m to 589 m, which are in high agreement with the observation. The new model can represent characteristics that UUL starts earlier than upward connected leaders (UCL) and channels of UUL are straight in a real CG lightning case F1215. It can also simulate 4 typical connecting behaviors which are observed in natural CG lightning flash, including the tip of downward leader (DL) to the tip of upward connecting leader (UCL) and the DL's tip to the lateral surface of UCL in cases where one or more upward leaders starts. The comparison with the observation proves that the simulation is reasonable to some extent and provides a basic model. By analyzing the simulated CG lightning data and morphological characteristics, it shows that the highest tower can protect a certain area of buildings nearby and attract more distant downward leader branches. The inception of multiple upward leaders and the strike point of last jump are influenced by the distribution, height of high structures and the initial position of the DL, which are of great significance to the lightning protection. |
| |
| Keywords: | |
|
| 点击此处可从《应用气象学报》浏览原始摘要信息 |
|
点击此处可从《应用气象学报》下载全文 |
|
