Characterization of Lightning Electric Field Waveforms Using a Large Database: 2. Analysis and Results

Dependence of lightning electric field waveform parameters on distance between the lightning channel and the field measuring point is examined. The analyses are performed based on representative wideband electric field waveforms that were obtained by averaging individual waveforms produced by negative return strokes at distances ranging from 10 to 500 km. The methodology employed for finding the representative waveforms using a large database is described in the companion paper. In this article, we present evolution with distance of the following waveform parameters: zero-to-peak rise time, zero-crossing time, ratio of the initial electric field peak to the opposite polarity overshoot, all for the ground wave, and the ratio of the ground wave initial electric field peak to the peak of the first skywave. We also present a catalog of representative waveforms for different distances, time of day, and stroke order. Additionally, we examine the peak-to-peak and zero-to-zero time intervals between the ground wave and the first skywave that are often used for estimating the apparent ionospheric reflection height.