Characterization of negative cloud-to-ground lightning in Florida

摘要: Abstract We examined characteristics of negative cloud-to-ground lightning flashes using their electric field waveforms acquired at the Lightning Observatory in Gainesville (LOG), Florida summers 2013 and 2014. Flash multiplicity, interstroke interval, flash duration, first to subsequent stroke peak ratio are determined for 478 containing 2188 strokes compared with previous results obtained other regions. found that average number per is 4.6 percentage single-stroke 12%. The geometric means 52 ms, 223 ms, 2.4, respectively. About one-third (34%) multiple-stroke have least one whose greater than stroke. mean normalized shows a relatively weak tendency decrease increasing order. also detectability preliminary breakdown (PB) pulse train affected by signal/noise ratio, type storm, current distance. For 222 PB trains, statistics on time interval between return (PB–RS interval), PB–RS (PB/RS ratio) presented. Very short (≤6 ms) intervals were observed be associated very high return-stroke currents stepped-leader speeds.