Mapping the cloud-to-ground lightning occurrence in Fiji

Abstract

Using the Time Of Group Arrival (TOGA) of sferics two year (Jan2003-Dec2004) annual average of about 3,200 and 1,200 cloud-to-ground (CG) flashes were recorded in the two larger islands, Viti Levu and Vanua Levu, Fiji. A two year average CG flash density showed maxima of 0.80 and 0.35 flashes/km2 per year in two islands. The diurnal variation showed peak activity between 14:00 hrs- 16:00 hrs LT and the seasonal variation showed enhanced lightning incidences during November-April. Data from Lightning Imaging Sensor (LIS) aboard the NASA Tropical Rainfall Measuring Mission (TRMM) satellite are also presented for the same period at the two locations. Lightning in a 10 km ×10 km area was compared with total rain accumulation at a site midway in the area which shows good correlation.