Temporal features of different lightning events revealed from wavelet transform

Abstract

Various lightning events are analysed using wavelet transform. The events include PB pulses, stepped leaders, first return strokes, subsequent strokes associated with negative ground flashes, positive return strokes and narrow bipolar pulses. Time domain electric fields were recorded from tropical and temperate thunderstorms. PB pulses pertinent to the tropical thunderstorms are found to radiate in the average frequency range 51–739kHz. Leaders are found to radiate in the frequency range 87–720kHz. The energy radiated by the negative return strokes is predominant in the range 2.8–40kHz. The energy radiated by the first subsequent strokes predominantly lies in the frequency range 4.5–55kHz. Positive return strokes are found to radiate predominantly in the frequency range 5.5–81kHz. Narrow bipolar pulses are found to predominantly radiate in the frequency range 58–714kHz.