Mercury Rising

Written By: / Articles / Monday, 02 May 2022 17:10

India has been in the grip of what seems like an eternity of heatwaves. April temperatures over north-west and central India are the highest in 122 years. During April 1 to 28, the average monthly maximum temperature over northwest India was 35.9° Celsius and the same over central India was 37.78° C. These averages belie measurements at the district and sub-divisional level where several parts of Rajasthan, Punjab, Haryana, Gujarat, and Maharashtra have seen temperatures inch towards the mid-40s and breach normals. There is little respite expected in May, which is anyway the hottest month, though the India Meteorological Department (IMD) says that while north and west India will continue to sizzle on expected lines, and must likely brace for more heatwaves, the rest of the country is unlikely to see the levels of March and April. A heatwave is declared when the maximum temperature is over 40° C and at least 4.5 notches above normal. A severe heatwave is declared if the departure from normal temperature is more than 6.4° C, according to the IMD. The proximate causes for the searing heat are an absence of rain-bearing Western Disturbances, or tropical storms that bring rain from the Mediterranean over north India. Cool temperatures in the central Pacific, or a La Niña, that normally aid rain in India, too have failed to bolster rainfall this year. This is an unusual occurrence.
Despite five Western Disturbances forming in April, none was strong enough to bring significant rain and depress temperatures. The IMD has forecast a ‘normal’ monsoon or 99% of the Long Period Average (LPA) of 87 cm and is expected to forecast the monsoon’s arrival over Kerala later in May. On the surface, there is no direct bearing between the intensity of heatwaves and the arrival and performance of the monsoon. In fact, even as northern India baked for want of rain, April saw monthly rainfall break a four-year record with high rainfall in several parts of southern and north-eastern India. May too is expected to see 9% more rain over India than is usual for the month, though it must be kept in mind that base rainfall is so low in this month that it is unlikely to make a mark. While individual weather events cannot be linked to greenhouse gas levels, a warming globe means increased instances of extreme rain events and extended rain-less spells. What is better known is it helps to have disaster management plans in place that help States better deal with heatwaves and their impact on health. The official toll due to heatwaves in the last 50 years is put at over 17,000 people, according to research from the IMD. The heat island effect means urbanisation adds degrees to the already searing conditions; and so, heatwave deaths must be treated as a disaster that merits compensation. Private and public workplaces too must be better equipped to factor heatwave risk.

About the Author

Vijay Garg

Vijay Garg

Vijay Garg is a regular contributor of Imphal Times, mostly related with Education. Vijay is a resident of Street Kour Chand MHR Malout-152107 Distt Sri Muktsar sahib Punjab. Vijay Garg, Ex.PES-1 is a retired Principal from Government Girls Sen Sec school Mandi Harji Ram Malout -152106 Punjab. He is also the author of Quantitative Aptitude, NTSE , NMMS, Mathematics of XII, ICSE numerical physics and chemistry many more books.

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