雷暴中“伴生闪电”的时空活动特征及其互作用机制研究

Associated lightning discharges are associated phenomenon of lightning discharges activity and may be widespread in thunderstorm. And their interaction mechanism and characteristic of space-time distribution are followed closely by researcher. Using a lightning mapping system and auxiliary equipment, the experimental observation of lightning discharges would be carried out in inland plateau in this project. The uninterrupted three-dimensional location data, electric field data on sounding balloon and electric field on ground of lightning discharges would be caught. To establish the mathematical physics model based on dual electrically active cells (EACs), and associated lighting discharges would be discerned with a criterion of space time interval, and their space time distribution would be analyzed in thunderstorm. Combined the analysis of radar echo, electric field and electric field change and so on, the electrical structure of thunderstorm and its evolution would be inferred, and its action on forming period of associated lightning discharges would be analyzed. Further, basing on anlysis of charge neutralization, charge transport and charge sediment, the different kinds of associated lightning discharges and their interaction mechanism would be studied. This work would improve understanding to space-time distribution of associated lightning discharges in thunderstorm and their interaction mechanism, and could deepen research on macro regularity of thunderstorm electrical activity, and could provide important observation fact on atmospheric electricity. It has important scientific value.

“伴生闪电”（Associated lightning discharges）是雷暴中普遍存在的闪电放电活动伴生现象，其时空分布规律及伴生机制受到广泛关注。本项目拟在内陆高原地区，利用闪电VHF辐射源三维定位系统及配套设备，开展对雷暴中电学活动的观测，获取完整的雷暴电学活动三维定位、地面电场及空中电场等数据。建立基于双电学活动单元的数学物理模型，拟定合理的时空间隔鉴别标准，识别伴生闪电并分析其时空分布规律。结合雷达回波、电场及电场变化等分析，反演雷暴电荷结构及演变过程，分析其在伴生闪电形成中的作用。并在闪电放电过程中电荷中和、输送、沉积等分析基础上，对不同类型伴生闪电中首次放电活动对继后电学活动抑制、诱发、甚或触发作用的物理机制进行研究。研究结果不仅可促进对伴生闪电时空分布特征、伴生机制的深入认识，深化雷暴电学活动宏观规律研究，也进一步为大气电学研究提供重要观测事实，具有十分重要的科学价值

利用闪电VHF辐射源三维定位系统及配套设备，在青藏高原东北部开展了两次对雷暴中电学活动的综合观测，另在云贵高原开展光学观测和电学同步野外观测一次，获取了完整的雷暴电学活动三维定位、地面电场、光学等数据。建立了基于双电学活动单元的数学物理模型，研究了雷暴中闪电辐射源时空间隔规律。结合雷达回波、电场及电场变化等分析，分析了雷暴电荷结构及其演变过程，实现了NBE放电事件的自动识别，结合电荷结构演变分析和数理模型进行了闪电类型分类，分析了电荷结构变化对闪电类型的影响，探讨了电荷转移对不同放电单元环境电场的改变，对有无NBE存在的闪电预击穿过程脉冲丰富度及脉冲间隔进行了分析，并对NBE形成的放电通道头部电场变化进行了初步分析。研究结果在一定程度上促进了对伴生闪电时空分布特征、伴生机制和雷暴电学活动宏观规律的认识。获取的资料为大气电学研究提供了重要基础资料库，相关分析为雷电、雷暴的研究提供了重要的参考。