卫星与地基闪电探测资料在闪电活动研究中的综合应用

利用闪电探测资料研究闪电放电特性及其活动特征,对于雷电灾害的监测和预警具有重要意义。卫星闪电探测不受下垫面条件限制,可观测覆盖区域内的总闪电,但无法区分云闪与地闪,地基闪电探测以定位地闪为主,且二者探测原理不同。本文分析了卫星与地基闪电探测在观测目标、定位精度和探测率等方面的差异;在此基础上,利用卫星闪电成像仪TRMM LIS与我国国家雷电监测网资料,提出一种结合星地同步闪电观测数据的闪电活动分析方法,该方法对两种资料中时空特性较为相近的探测单元进行匹配处理,通过聚类算法得到闪电信息;利用该方法分析了我国西南地区2008~2014年的闪电分布特征。结果表明:该方法可有效获得观测区域的闪电信息,且从气候与地形因素等方面可对分析结果给予解释;下一步结合静止卫星闪电探测资料,可从数据匹配误差上获得改进,同时可将多源闪电观测资料结合的方法扩展到更多应用。

Combined application of lightning detection data from satellite and ground-based observations

Research on the lightning activities by taking advantage of the lighting detection data from satellite and ground-based observations is of great importance for lightning monitoring and early warning for thunderstorm. A satellite-based lightning imager can detect lightning signals over both ocean and land areas, and provide total lightning data including intracloud and cloud-to-ground lightning. However, a ground-based lighting location system usually gets the cloud-to-ground lightning. The two ways detect optical and radiometric emissions from lightning respectively. Firstly, the differences between satellite and ground-based lightning detection were analyzed in the aspects of the observed objective, location accuracy, and detection efficiency. Secondly, based on the data of TRMM LIS and the ground-based lightning detection network over China, a method for combination of satellite and ground-based lightning detection data was proposed. More specifically, by matching the similar units from both kinds of data and clustering the lightning groups, the combined lighting flashes could be extracted. Finally, the method was used in analyzing the lightning activities in southwest China from 2008 to 2014. The results show that the proposed method is feasible from the perspective of climatic and topography factors. In future, by integrating the data of geostationary satellite-based lightning imager, the matching error can be decreased, and the improved method will be applied to more solutions.