Detection Efficiency And Accuracy Assessment Of World-Wide Lightning Location Network(WWLLN)

In recent years, disasters caused by lightning are becoming increasingly severe, not only for the safety of public property, but also for the safety of people’s lives will be brought with great losses and serious hidden danger. Effectively monitoring and forcasting lightning, which could deepen understanding of the laws of lightning activity, reducing the losses caused by lightning in large extent. With the lightning location technology developed, more and more experts and scholars turn their attention from the lightning microphysical processes to the quality analysis of the data recorded by the lightning location network. However, the discussion of the data is often limited to a single or two systems and a particular region. This paper attempts to break this limitation, using four different lightning location networks, the Worldwide Lightning Location Network(WWLLN), Jiangsu Lightning Location Network ADTD, the Nationwide Lightning Location Network and Spaceborne OTD/LIS system, to study lightning activity in different areas including Jiangsu Province, China, the world. A performance assessment of the WWLLN, including detection efficiency and detection accuracy in different areas, is presented using the ADTD, the Nationwide Lightning Location Network, Spaceborne OTD/LIS system data as truth. The results of this paper is kind of reference to WWLLN data quality reliability verification in the future and of great significance to lightning real-time monitoring and forcasting in different regions. In this paper, the main results are as follows:(1)2006-2009lightning activity in Jiangsu Province is not very different between day and night; lightning mainly occurred in late spring and midsummer, showing a single peak feature. June-August is high incidence time of lightning; Jiangsu Province lightning diurnal variation of peak is concentrated around the local13:00-20:00, lightning valley time is about local2:00-11:00. The WWLLN detection efficiency has increased year by year in Jiangsu Province. Furthermore, WWLLN detection efficiency has high sensitivity of return stroke peak current. Return stroke peak current greater, the higher WWLLN detection efficiency, and WWLLN positive CG lightning detection efficiency is higher than the negative. There is a good correspondence between WWLLN detection accuracy and ADTD. Jiangsu Province Lightning distribution of high-value area is located in the western and southern regions, roughly coincides with the geographical distribution of the economically developed regions in Jiangsu, so these areas need more emphasis on lightning protection. (2)2008-2010daytime lightning activity is slightly larger than the night in China; the national lightning activity monthly variation is normally distributed. August is the lightning activity peaktime; the WWLN detection efficiency increased year by year in China, with the highest detection efficiency in winter. The WWLLN detection accuracy geographically corresponds roughly to the National Lightning Location Network, and there are three major areas of high incidence of Lightning:Guangdong, Hubei Province and its surrounding areas, southeast along the coast. The WWLLN detection accuracy shows that lightning density is about one-tenth of the National Lightning Location Network in China.(3) WWLLN global detection efficiency is increasing year by year with the growth number of of WWLLN stations across the world, of which the largest growth in2007-2008, which is due to the WWLLN positioning technology algorithm upgraded in the end of2007. The WWLLN global dection accuracy shows that, three are three lightning chimney areas in the world. They are the Congo Basin, North America and most regions of South America, Southeast Asia and Australia in descending order. WWLLN global average lightning density is about one order of magnitude of the Spaceborne OTD/LIS Network.