A two year climatology of cloud-to-ground lightning strikes for the Kwajalein Atoll has been compiled. This is a unique climatology for the equatorial north Pacific where the frequency of atmospheric electricity has been widely debated. There are four lightning detectors in the network that are located around the Kwajalein Atoll. Since the islands are small, this is truly a study of oceanic lightning. The coral atoll is located approximately
4000 km west-southwest of Honolulu. The sensors of the system employ a basic direction finding method. When two or more sensors detect a flash of cloud-to-ground lightning at the same time and where the location of a strike is found to be at the intersection of two or more sensors azimuth angles a flash is recorded.
The climatology presented spans the period from 1 January, 1996 to 31 December, 1997 covering an area from 5N to 10N and 165E to 172E. Over this period 7524 flashes were recorded within the region over the course of 253 days. 5.4% of recorded flashes were positive. A diurnal peak of flashes occurred between 1700 UTC to 2000 UTC (0500L-0800L). A secondary maximum of flashes occurred near 0900 UTC (2100L). A relative minimum of flashes occurred at 0500 UTC (1700L). Seasonally, two relative maxima and minima of flashes were observed. There was a maximum in March-April and then in August-September-October. Minima were seen in February and May-June-July.
A case study of lightning associated with Tropical Storm Keith (29W) on 27 October 1997 will be presented. The lightning recorded with this event was associated with feeder bands from the tropical storm during its passage 150 km south of the Kwajalein Atoll. Lightning activity was focused from a period from 1500 - 1800. Numerous strikes were recorded and observed over the northern portion of the atoll. Along with data from the lightning system, DWSR-93S doppler radar data is used to investigate the structure of the bands
that produced the lightning.