Characteristics of lightning flashes over the Indian region

Abstract. Satellite (Lightning Imaging Sensor) based lightning flash grid (0.5 x 0.5) data over the land mass areas of the Indian region covering between 8-30N for a period of 4 years (1998-2001) have been analyzed to examine their geographical, annual, interannual and diurnal distribution. An attempt has been made to obtain IC:CG ratio. Result of this study demonstrates that there exists latitudinal variation of lightning flash density which is also confirmed through the ratio analysis. The annual variation of lightning flash density exhibits typical bimodal variation during its annual course. Time series of this parameter shows a consistent increase in the peak values. The diurnal variation of lightning flash count revealed that there exists a strong diurnal cycle with a prominent peak at 1000 hrs UTC over this region. The values of intra cloud flash (IC) to cloud to ground flash (CG) ratio are found to be more or less equal to the values reported by other investigators for the tropics.