A lightning climatology of northeast India:1998-2007

About 55,000 lightning flashes were recorded by the Lightning Imaging Sensor (LIS) during the 10-year period (1998-2007) in northeast India (NEI) and were analyzed to study their total climatology, seasonal, annual and inter-annual variations. The results suggest that the western region of the northeast India is prone to a maximum amount of lightning activity and the northeast and eastern part is minimal in activity. The activity shifts west and east as the season advances. It is stagnant in the western and southwestern region in the last season of the year. The highest percentage of activity is observed during the pre-monsoon season. During the annual course the activity exhibits bimodal variation giving an average value of 8.4 flashes/pass. The time series analysis of the parameter shows that the activity over NEI shows a consistent increase from 1998 to 2002 and then onwards it shows a consistent decrease. The activity in December is a characteristic feature for the region. The highest magnitude of activity is noticed in the year 2001 with 20 flashes/pass