Duct Lifetimes at Mid Latitudes

Abstract

The power spectrum analysis of the occurrence rate of whistlers observed at Varanasi (geom. lat. 14^o 55' N) shows periodicity of the order 70-80 min which has been interpreted as the lifetimes of the ducts trapping and guiding the whistlers. This is also corroborated by the dispersion analysis of the recorded whistlers. The observations clearly favour the existence of large numbers of ducts simultaneously. The analysis shows that these whistlers had propagated in the magnetosphere along higher L-values (L = 2.1-2.7).