A GPS-based system for 3-dimensional total lightning mapping observations

This paper describes a system that maps the total lightning activity inside storms. The system is called the Lightning Mapping Array (LMA) and uses time-of-arrival measurements from a countywide network of stations to locate VHF radio signals from lightning. The LMA monitors the lightning activity over an area 400-500 km in diameter, and produces detailed 3-dimensional images of the lightning over a central region about 150 km in diameter. Both individual lightning flashes and the overall activity of a storm are mapped. The system monitors the plan location and motion of electrically active storms over the coverage area, and can do so in real time. Within the 3-dimensional coverage region, the lightning activity shows the occurrence of overshooting convective tops and of `lightning-free' regions in supercell and tornadic storms, believed to indicate the location of strong updrafts in the storms. The system has been operated in Oklahoma, New Mexico and, most recently, during the STEPS program in northwestern Kansas and eastern Colorado. The accompanying figure shows accumulated real-time observations for a two hour time period on July 3, 2000 over the tri-state KS-CO-NB region during STEPS.