Agencies MUMBAI, Oct 21: The northward shift in summer winds, which occurred after 1998, is responsible for worsening heatwaves over North-Central India, according to a study led by the Centre for Climate Studies at the Indian Institute of Technology Bombay (IITB). This shift is responsible for 25 per cent of the observed variations in frequency, duration and total cumulative heat in summer hot spells in the region, said the study. Researchers suggested that this change in wind patterns was likely due to a jump in Pacific Ocean temperatures that happened around 1998, possibly made worse by global warming, the phenomenon of gradual rise in the Earth's average temperature. "We found that since 1998, the temperature over North-Central India has increased by about 0.7 °C (degree Celsius) during the pre-monsoon summer season. This increase appears to be due to the northward movement of the band of strong upper tropospheric winds, known as the subtropical westerly jet," Roshan Jha of IIT Bombay, the lead author of the study, explained. This change isn't affecting just India, but also nearby areas like neighbouring Pakistan and West Asia, he pointed out.
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