WWLLN and Earth Networks new combined Global Lightning Network: First Look

Lightning VLF sferic waveforms detected around the world by WWLLN (World Wide Lightning Location Network) and by Earth Networks WTLN receivers are being analyzed in real time to calculate the time of group arrival (TOGA) of the sferic wave packet at each station. These times (TOGAs) are then used for time-of-arrival analysis to determine the source lightning location. Beginning in 2016 we have successfully implemented the operational software to allow the incorporation of waveforms from hundreds of Earth Networks sensors into the normal WWLLN TOGA processing, resulting in a new global lightning distribution which has over twice as many stroke locations as the WWLLN-only data set. The combined global lightning network shows marked improvement over the WWLLN-only data set in regions such as central and southern Africa, and over the Indian subcontinent. As of July 2016 the new data set is typically running at about 230% of WWLLN-only in terms of total strokes, and some days over 250%, using data from 65 to 70 WWLLN stations, combined with the VLF channel from about 160 Earth Networks stations. The Earth Networks lightning network includes nearly 1000 receiving stations, so it is anticipated we will be able to further increase the total stations being used for the new combined network while still maintaining a relatively smooth global distribution of the sensors. Detailed comparisons of the new data set with WWLLN-only data, as well as with independent lightning location networks including WTLN in the CONUS and NZLDN in New Zealand will be presented.