Study of amplitude spectrum of VLF sferics and vertical electric field at Kolkata

Abstract

From the measurements of atmospheric electric field and VLF sferics at Kolkata (22^o34´ N, 88^o30´ E), some correlation studies have been made. It is observed that the diurnal variation of vertical electric field averaged for 20 fair weather days maintains good connectivity with diurnal variation of VLF sferics activity. The variations are in contrast with the accepted unitary diurnal changes of vertical electric field and thunderstorm occurrence frequency curve with a maximum around 1900 hrs UT and a minimum around 0400 hrs UT. Some results in this context are presented in this paper.