| 基于闪电先导随机模式对不同连接形态的模拟 |
| |
| 引用本文： | 廖义慧,吕伟涛,齐奇,张荣,张冬冬,谭涌波,张义军.基于闪电先导随机模式对不同连接形态的模拟[J].应用气象学报,2016,27(3):361-369. |
| |
| 作者姓名： | 廖义慧 吕伟涛 齐奇 张荣 张冬冬 谭涌波 张义军 |
| |
| 作者单位： | 1.南京信息工程大学大气物理学院，南京 210044 |
| |
| 基金项目： | 资助项目： 国家自然科学基金项目（41475003，51420105011），中国气象科学研究院基本科研业务费项目（2014R015），国家重点基础研究发展计划（2014CB441405） |
| |
| 摘 要： | 考虑到下行负极性地闪过程中大多上行正先导发展时不分叉的观测事实，基于已有的闪电先导二维随机模式，改变上行正先导的模拟方案，使其发展时不产生分叉，并对雷击高建筑物过程中下行先导与上行连接先导 (upward connecting leader，UCL) 之间头部-头部连接和头部-侧面连接 (侧击) 的两种形态进行模拟。以高度为440 m的建筑物为例，通过改变下行先导始发点 (高度为1000 m) 与高建筑物的水平距离，模拟高建筑物上雷击过程中先导之间的连接过程，结果表明:当下行先导始发点与高建筑物的水平距离从0增加到700 m时，UCL的长度呈持续增大趋势，UCL受侧击的概率总体上呈先增大后减小的趋势 (在距离为500 m时达到最大值58%)，侧击时UCL连接点以上的部分占整个UCL长度的比例总体呈持续增大趋势 (13%~49%)。
|
| 关 键 词： | 高建筑物 连接点 接地点 侧击 |
| 收稿时间： | 2015-11-02 |
Simulation of Various Connecting Patterns During the Lightning Connection Process Based on the Stochastic Lightning Leader Model |
| |
| Affiliation: | 1.College of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing 2100442.Laboratory of Lightning Physics and Protection Engineering, State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 1000813.Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044 |
| |
| Abstract: | Considering the observed fact that most upward connecting leaders (UCL) does not branch during downward negative cloud-to-ground (CG) strikes, the simulation scheme of upward positive leaders is modified based on the existing two-dimensional (2D) stochastic lightning model. In addition, two connecting patterns, i.e., the tip-to-tip connecting and the tip-to-lateral connecting (lateral strike) between the downward leader and the UCL are simulated during the process in which lightning strikes tall buildings. Sensitivity experiments are carried out on the connecting process between leaders during the process of lightning striking a tall building by altering the horizontal distance between the initiation point of the downward leader (at a height of 1000 m) and the tall building. Results indicate that when the value of d increases from 0 to 700 m, the probability of a lateral strike for the UCL generally exhibits a trend of first increasing and then decreasing. As the value of d increases, the length of the UCL exhibits an increasing trend, and the ratio of the part of the UCL above the connecting point accounting for the entire length of the UCL upon the lateral strike generally exhibits an increasing trend. The probability of each grounding position is under the influence of the horizontal distance. The UCL initiating from the top of tall structures is longer than that initiating from the ground or the side surface of tall structures. Furthermore, tall structures with different heights are also investigated. |
| |
| Keywords: | tall structures connecting point grounding point tip to lateral |
|
| 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 |
|
