Beschreibung:
El-Niño and La-Niña are believed to change the intensity and frequencies of extremeweather events globally. The present study aims to analyse the impact of El-Niño and La-Niña on thelightning activities of cloud systems and their associated precipitation and thermodynamic indicesover the Eastern India regions (Odisha, Jharkhand, and West Bengal) during the pre-monsoon season(March–May). Eastern India receives catastrophic thunderstorm events during the pre-monsoonseason. The results suggest that the number of lightning flashes was higher in the El-Niño yearsthan in the La-Niña periods, which helps convective activities to be developed over the study region.The precipitation variations showed similar patterns during El-Niño and La-Niña periods, but themagnitudes were higher in the latter. Results from the analysis of thermodynamic indices show that,during the La-Niña phase, the convective available potential energy (CAPE), convective inhibition(CIN), severe weather threat index (SWEAT), humidity index (HI), and total totals index (TTI) valuesincreased, while the cross total index (CTI) and K index (KI) decreased. In contrast, the verticaltotal index (VTI) and Boyden index (BI) values showed less significant changes in both El-Niño andLa-Niña periods. The anomalies of flash rate densities over most parts of our domain were positiveduring the El-Niño years and negative during the La-Niña years. Precipitation anomalies had ahigher positive magnitude during the La-Niña phase, but had spatial variability similar to the El-Niñophase. The anomalies of most of the thermodynamic indices also showed noticeable differencesbetween El-Niño and La-Niña periods, except for the HI index. El-Niño periods showed higherlightning and increased values of associated thermodynamic indices over eastern India, indicatingmore pronounced convective systems.