1 week Ago
Contradictory to earlier claims, the latest research conducted by scientists from the India Meteorological Department (IMD), Pune, highlighted that the dynamics of El Nino Southern Oscillation (ENSO) has a significant contribution to an increase in the heatwave days in Southern India. The report highlighted that, as compared to North and Northeast India, Southern Peninsular India (central and northwest India) experiences more heatwaves in the year of ENSO condition. The study titled ‘Dynamics of ENSO linked contrasting heat wave patterns over the Indian region’ was published on April 6 in the international journal Climate Dynamics.
Scientists from IMD including SD Sanap, P Priya, JS Chowdary, and DR Pattanaik participated in this study. Earlier studies have demonstrated that heat waves tend to become more prolonged, intense, and widespread following an El Niño event. However, during the spring of 2022, central and northern India experienced persistent and widespread heat waves despite a strong La Niña.
This anomaly prompted scientists to examine the spatial temperature patterns associated with ENSO events and their atmospheric dynamics. During the El Niño years, southern peninsular India experienced higher-than-normal maximum temperatures, increased heat wave occurrences, and reduced precipitation. In contrast, northwest India tends to witness cooler-than-normal temperatures and higher precipitation.
The reverse pattern is observed during La Niña, with northwest India becoming hotter and drier, while southern peninsular India is cooler than normal with increased rainfall. For this study, the fifth-generation reanalysis dataset from the European Centre for Medium-Range Weather Forecasting (ECMWF) covering the period from 1979 to 2023 is utilised for the atmospheric variables at a monthly timescale on a 0.25° × 0.
25° grid. Additionally, monthly precipitation data at 0.25° and temperature data at 0.
5° spatial resolution were used from the IMD. Speaking about the significance of the study, SD Sanap senior meteorologist from IMD Pune, said that this study helps understand the atmospheric conditions and their impact on the weather. “It will help us to improve the seasonal forecast, especially for the summer season.
Scientific understanding of the heatwave patterns has been identified by this study.”.
