More heat waves, fewer cold waves the new normal in India: UoH study

The occurrence of anomalously higher temperatures for consecutive three days or more is referred to as a heat wave event and it was found heat wave events are increasing at the rate of 0.6 events per decade.

Women cover themselves with scarfs and caps to protect themselves from heat waves on a hot summer day, a scene at Bandar Road in Vijayawada on Thursday. | Photo Credit: G.N. RAO

University of Hyderabad (UoH) researchers have found that days with anomalously higher temperatures are increasing during summer while the days with anomalously lower temperatures are decreasing during winter every year.

The occurrence of anomalously higher temperatures for consecutive three days ormore is referred to as a heat wave event and it was found heat wave events are increasing at the rate of 0.6 events per decade whereas the cold wave events are decreasing at the rate of 0.4 events per decade.

The study led by Master of Science in Ocean and Atmospheric Sciences, 2020-2022 batch student Aninda Bhattacharya showed that heat waves have become more common in summer in the recent decade while cold waves have less so common in winter in India.

The student used daily maximum temperature and minimum temperature data from 1970 to 2019 to investigate the trend in the frequency of occurrence of days with anomalously high temperatures (referred to as heat waves) and days with anomalously low temperature (referred to as cold waves) over different climatic regions of India.

The authors also compared the current-generation computer models used to predict future climate with India Meteorological Department (IMD) observations. Heat waves are found to be more common over the arid and semi-arid climatic region while cold waves are less so common over the same region.

Others who were part of the research team are: Abin Thomas and Vijay Kanawade from Centre of Earth, Ocean and Atmospheric Sciences, School of Physics, UoH; with other collaborators being IIT Madras’s Chandan Sarangi, World Resources Institute’s (WRI) P. S. Roy from and IMD’s Vijay K. Soni. The study has been published in The Journal of Earth System Science (https://www.springer.com/journal/12040)., said a press release.