Using the World Wide Lightning Location Network (WWLLN) to Study Very Low Frequency Transmission in the Earth‐Ionosphere Waveguide: 2. Model Test by Patterns of Detection/Non‐Detection

Abstract

AbstractThis is the second half of a two‐part study. In the first part, we had used the World Wide Lightning Location Network's (WWLN) recorded signal amplitudes to test a model of Very Low Frequency signal transmission from the lightning to each sensor. The model predicts a dramatic worsening of transmission at low magnetic latitudes, for nighttime propagation (compared to daytime propagation) toward magnetic West. However, we found that the use of amplitudes was ill‐adapted for testing the model under conditions of a deep outage of transmission. Since the relative weakening of nighttime transmission is rather counter‐intuitive, we have now developed an alternative approach to testing that model prediction. This alternative approach highlights the patterns of detection/non‐detection of several low‐magnetic‐latitude WWLLN stations and compares those patterns with the appropriate patterns of the model transmission.