Seasonal and Regional Differences in the Lightning Activity Over East and West Coasts of India

This study analyzed lightning activity along the east and west coasts of India using Lightning Imaging Sensor (LIS) for a 20-year period (1995–2014). For this study, we divided the coasts into four sub-regions with 5° × 5° grid resolution: R1 & R2 on the west coast (Maharashtra & Goa, Kerala respectively) and R3 & R4 on the east coast (Tamil Nadu & Southern Andhra Pradesh, West Bengal & Orissa respectively). To understand the factors influencing these different regional patterns, we investigated various meteorological parameters such as rainfall, wind, specific humidity, brightness temperature (BT), Convective Available Potential Energy (CAPE), lifted index (LI), K-index (KI) and total totals index (TTI). During the pre-monsoon months, R4 on the east coast and R2 (Kerala) on the west coast displayed the most lightning activity compared to other regions. However, during monsoon R3 and R4 on the east coast displayed the most lightning activity. Both coasts exhibited peaks in CAPE coinciding with peaks in lightning activity, suggesting CAPE plays a role in modulating lightning characteristics. The convergence of moisture transporting south-easterlies and westerlies potentially contributes to its high pre-monsoon lightning activity over R4. In contrast, westerly winds might influence post-monsoon activity in the western and southern regions (R2 & R3). The study also revealed a potential association between regional variations in lightning activity and the width of the mixed-phase region, along with its Ice water content (IWC) and Liquid water content (LWC). Conversely, rainfall is positively correlated with higher LWC in the lower atmosphere rather than in the mixed-phase region. Our findings underscore the importance of continuous lightning monitoring in dynamic coastal regions to deepen our understanding of these natural phenomena and enhance lightning prediction and safety measures.