Spatio‐temporal variability of lightning activity over the Indian region

Abstract

[1] Spatio-temporal variability of lightning activity over the Indian land mass region (8°N-33°N, 73°E-86°E) has been studied using monthly satellite based lightning flash grid (5°Â 5°) data for 5-year (1998-2002) period. These data have been examined for depicting the annual, seasonal, and spatial distribution of the lightning activity. The study revealed the nonlinear relationship between lightning flash density and latitude on the annual timescale, and it is linked with the convective activity, large-scale circulations, land mass gradient, and orography of the region under study. On the seasonal timescale, the nonlinear positive relationships were observed in the premonsoon and monsoon seasons whereas a bimodal variation is observed in the post-monsoon season. The comparison of flash density with maximum surface air temperature shows the existence of nonlinear relationship between the two parameters. The approximate range of increase of flash density per 1°C rise in temperature is 20 to 44%. The lightning flash density shows a pronounced semiannual oscillation over the latitude belts 8°N-28°N.

Land‐ocean contrasts in lightning activity over the Indian region

“…Over AS, minimum activity is seen in July and August at 10°N. Slightly higher activity at 15°N in October and November months may be related to the convection developed by western disturbances (Kandalgaonkar et al, 2005). Over BoB, the activity starts from January and increases to attain maximum in the month of May at 10-11°N.…”

“…These colder SSTs are not favourable for the development of the convection. Kandalgaonkar et al (2005) showed that the orography of the region is one of the factors controlling the convective activity and hence lightning activity. Thus, the observed higher FD along the eastern part AS may be attributed to the combined effect of orography, land-sea interaction and warmer SSTs.…”

“…The lightning flash data have been collected for 1°× 1°grid over the oceans and 5°× 5°grid over the land. The results over the land region were published in (Kandalgaonkar et al, 2005). Over oceanic region smaller grid (1°× 1°) is taken so as to avoid land in the boundary region.…”

“…The study revealed that over BoB the thunderstorm activity was higher due to warmer SSTs. Kandalgaonkar et al (2005) examined the spatiotemporal variability of lightning activity over the Indian land-mass region. Their results showed that orography, large-scale atmospheric circulation and land-mass area of the region play important roles in controlling the convective activity and hence lightning.…”

Association of Rainfall and Stability Index with Lightning Parameter over the Indo-Gangetic Plains

“…Prior to the onset phase of the monsoon, the Indian land mass region experiences maximum convective instability caused by insolation [18] It is seen from Figure 6 that the negative LI is seen over March to September.…”