The investigation of the effects of lightning on the subionosphere by using VLF propagation

n this thesis, narrowband analysis of VLF signals of July, August and September, 2005 have been done. The VLF signals of HWU, HWV, ICV and SIC transmitters at Europe are recorded by the VLF Receiver System at Firat University which is supported by TUBITAK (Project No:104E005) and NSF. The obtained data have been analyzed for the investigation of the relation between LEP events and lightning, geomagnetic indices and determination of the temporal characteristics of LEP events and the relationship between them.The reason for the LEP events established at the no-lightning data time interval is breakdown of the Lightning Record System or other mechanisms at the existence of LEP event. The days of full time lightning data and the LEP events determinate on the continuously recorded signals have been compared and assigned directly proportional.Temporal characteristics of LEP events have been investigated. There is no relation between them and each LEP event is unconnected from other.Generally, a directly proportional relation between increase of the number of the LEP events at maximum lightning days and Kp indice and also no increment at the number of the LEP events at low Dst indice days have been obtained.