Evaluating the Influence of El Nino-Southern Oscillation (ENSO) Patterns on the Spatio-Temporal Variations of Drought over Southern Peninsular Indian Region

The El Nino-Southern Oscillation (ENSO) occurrences derive the substantial variability in precipitation which may cause threatening climate change and severe drought occurrence in a specific region. In this present study, the role of ENSO events on changing climatic patterns in the view of drought has been analyzed over the southern peninsular Indian region for the period of 2 decades from 2000 to 2020. The year 2017 stipulated with the Sea Surface Temperature (SST) anomaly of 2.127 degrees C which is recognized as the Super El Nino year. The SST anomaly for the year 2015 is - 1.824 degrees C and is recognized as the Strong La Nina year. The climate-based Standardized Precipitation Index (SPI), Rainfall Anomaly Index (RAI), Standardized Precipitation Evapotranspiration Index (SPEI), and Aridity Index (AI) are derived in order to delineate the sensitivity response of climatic patterns on the basis of ENSO. During El Nino-2017, the study region sustained with SPI ranges from - 1.232 to 2.056, RAI ranges from - 3.541 to 4.907, SPEI range from - 1.476 to 1.872, and AI ranges from 0.657-3.891. In La Nina-2015, the study region stipulates SPI ranges from - 2.576 to 1.368, RAI ranges from - 3.546 to 6.495, SPEI ranges from - 1.682 to 1.791, and AI ranges from 1.144 to 4.028. Furthermore, correlation analysis has been performed to ensure their reliability. Accordingly, the indices like SPEI and AI are obtained with relatively high correlation, whereas SPI is discerned with the least correlation. Eventually, this study unveils that the influence of the ENSO pattern varied spatially and El Nino onsets almost lead to arid climatic conditions rather than the La Nina phase.