Fig. 2From: Lightning-associated VLF perturbations observed at low latitude: Occurrence and scattering characteristics(a)–(d) Typical examples of early/fast events observed on the NWC, NPM, VTX and NLK transmitters. Solid traces (blue color) and dotted traces (red color) represent the amplitude and phase, respectively. Dashed vertical lines indicate the time of WWLLN-detected lightnings.Back to article page