Why do heat waves occur in central india?
Answers
The India Meteorological Department (IMD) says the country is on an average 0.6 degree Celsius hotter than a century ago. 2016 was the warmest year since 1901. Until 2015, 13 of India’s 15 warmest years ever were after 2000. Heat waves are a sharply defined concept, as per Indian meteorology. Depending on whether a place’s historical temperature is 40C or less, a 4.5C (or greater) rise in temperature counts as a ‘heat wave’ and 6.5C and more, a ‘severe heat wave.’ The IMD counted the number of heat wave days in 110 weather stations nationwide and, in a 2013 report, found that between 1960 and 2010, there were about 510 ‘heat wave days’ every year in the decades 1961-70 and 1971-80. This decreased to 470 in (1981-90) and jumped to about 580 days/year and 670 days/year respectively in the decades (1991-00 and 2001-10). The same roughly holds for severe heat waves. From an average 74 days/year in the 1961-70 decade, it has jumped to 98 days/year in the last decade (2001-2010). Given that the last decade was the hottest, these numbers would likely be higher when re-tabulated after 2020