Residents of Kanpur division are unlikely to get any relief from the prevailing extreme heat conditions, as the India Meteorological Department (IMD) has forecast a further rise in temperature over the next two days.
On Sunday, the mercury in Kanpur crossed the 44.1 degrees Celsius mark, 4.3 units above normal. The Air Force observatory at Chakeri recorded 44 degrees Celsius, while city observatories, including Chandra Shekhar Azad University of Agriculture and Technology, registered 44.1 degrees Celsius.
The minimum temperature also rose significantly to 25.8 degrees Celsius, around 3 degrees above normal, indicating warmer nights ahead. Maximum relative humidity dropped to 42 percent, reducing the likelihood of effective sweating and thereby increasing discomfort.
According to IMD forecasts, the coming days will witness intense sunlight, rising daytime temperatures, and heat index levels hovering around 50 degrees Celsius. Hot and gusty winds are also expected during the day, sustaining severe heatwave conditions.
Heat Dome Phenomenon
Weather expert of CSA University, Dr S Sunil Pandey, told TOI that a heat dome, effective in the northern, central, and eastern India, is causing excessive hot climatic conditions in the entire central India region. Explaining heat dome, Pandey said, "A heat dome is a meteorological phenomenon in which a high-pressure area in the atmosphere acts like a lid or dome over a specific location. This traps warm air in one place, causing the ground and the air in that region to heat up continuously."
This heat dome remains the primary cause of the severe heat and heatwave currently prevailing in India, particularly in states such as Maharashtra, Telangana, Madhya Pradesh, Uttar Pradesh, and Delhi.
How Heat Dome Works
In a heat dome, a high-pressure area prevents warm air from rising. The pressure coming from above pushes the warm air downward, causing the air to compress and become even hotter. Air compression essentially means increasing the air pressure to confine it within a smaller space. When air is compressed using a machine (such as an air compressor), its molecules move closer together, resulting in the accumulation of energy (heat) within it.
Due to the downward pressure of the wind, clouds do not form; consequently, direct rays from the sun strike the ground, and the temperature reaches 45 to 50 degrees Celsius. This system can persist in the same location for weeks, thereby prolonging the spell of heatwaves, Pandey said.
In India, a stable anticyclonic system persists at an altitude of 10,000 to 20,000 feet over Maharashtra and its surrounding regions. In April and May, the sun rays are direct; when this coincides with a heat dome, the heat reaches its peak. Due to climate change, the frequency and intensity of the formation of such heat domes have increased.
Urban Heat Island Effect
Pandey said that in cities, this situation was further worsened by dry soil and sparse vegetation. Cities are now converted into concrete jungles and losing green cover, resulting in more heat. Describing preventive measures, he advised people to avoid stepping outside between 11 am and 4 pm.
