Acknowledgements
The authors are using data from the World Wide Lightning Location Network, a collaborative consortium of over seventy worldwide collaborators, managed at the University of Washington. The data would not exist but for the cooperative efforts of all of WWLLN’s participants. For sale to researchers who are not WWLLN participants, WWLLN data are available, at a nominal price to cover overhead costs of running the network, and archiving / distributing the data. To find out about such data access, see http://wwlln.net/