Observation of Lightning Discharges in Indonesia by Lightning Detection Network

A real-time lightning location network started to operate in Indonesia in mid 1995 and began providing reliable data in the end of the same year. The network consists of 8 signal receiving stations and works using the Time-Of-Arrival (TOA) technique. Area covered by the network includes: Java Island, Bali Island, Southern part of Sumatra Island, Southern part of Kalimantan Island, and Southern part of Sulawesi Island. The present work reports on the lightning stroke density obtained by the TOA network for 5 consecutive years from 1996 to 2000 on the Java Island. Maps of the lightning stroke density and its annual variations are presented. Further, monthly variation of the detected lightning strokes is also discussed. Lightning activity on the Island shows a consistent high density. The spatial and temporal distribution of lightning activity on the Island as reported by Hidayat and Ishii are confirmed. The density obtained using the present network is comparable to that reported by Hidayat and Ishii. On the other hand, the current amplitude is almost two-fold higher with an increasing tendency from 1995 to 1999