Effect of Climate Indices on Monsoonal Rainfall during El Niño and La Niña Events in the India

Abstract

This study examines the association between monsoonal rainfall and climatic indicators during India's El Niño and La Niña episodes. Indian monsoon rainfall is known to be greatly influenced by large-scale climate indices like the Pacific Decadal Oscillation (PDO) and the El Niño-Southern Oscillation (ENSO).The present study was conducted utilizing meteorological data from 10 rainfall sites across India. The India Meteorological Department (IMD), located in Pune, has gathered the data, which includes mean monthly precipitation (PPT), mean monthly lowest temperature, and mean monthly maximum temperature.To examine their combined impact on Indian monsoon rainfall, ENSO and the PDO a long-term climate oscillation including changes in sea surface temperatures in the North Pacific Ocean were taken into account.The study's goals are to examine the effects of ENSO on rainfall at various Indian meteorological stations and to analyze rainfall data for these stations.The data demonstrate that during most El Niño years, a drop in precipitation was found across all stations evaluated in the study. On the other hand, majority of the stations reported higher precipitation during La Niña years. Additionally, there were differences in the correlation between PDO and monsoonal precipitation among the stations: the PDO index showed a negative correlation with the remaining five stations, while the PDO index showed a positive correlation with Cherrapunji, Delhi, Hyderabad, Kolkata, and Mumbai.