Lightning activity over Telangana and Andhra Pradesh states situated in the east coast of India

Lightning activity over Telangana (17° N–19° N and 78° E–82° E), and the 13 districts of Andhra Pradesh (A.P) are studied using the data from the lightning imaging sensor aboard the Tropical Rainfall Measuring Mission (TRMM) satellite data during the period 1998–2013. It is observed that the flash rate density, flash count, and flash days over the study regions (Telangana, Rayalaseema, and coastal A.P) exhibit semi-annual variation with primary maximum in the pre-monsoon season (May–June) and secondary maximum in the post-monsoon season (September). The annual mean flash count is maximum (87.645) over Vishakhapatnam district, and flash rate density is maximum (0.058 fl km−2 day−1) over Srikakulam district compared to all other regions. The Inter-annual variation of lightning flash count shows that the lightning over Srikakulam district is increasing significantly. In Telangana, Rayalaseema (except Chittoor district), and coastal A.P (except Guntur, Krishna and Nellore) regions the flash count is highly correlated with surface temperature and convective available potential energy. The correlation of flash count with Aerosol Optical Depth and convective precipitation is very poor over these regions. This shows that the lightning over Telangana, Rayalaseema and in coastal A.P districts during pre-monsoon season is mainly due to buoyancy force developed because of the heating of land during daytime. The lightning flash Radiance values over Telangana, Rayalaseema, and coastal Andhra Pradesh regions are maximum during post-monsoon season (October–November). This study helps in understanding the spatio-temporal variation and the intensity of lightning activity over Telangana and A.P, which is first of its kind, over these regions.