US Warned Of Record Temperature As Heat Dome Shifts From Mexico

The year 2024 has seen unprecedented heatwaves scorching not only India but also various regions across the globe. In Mexico, a prolonged and deadly heatwave has killed at least four dozen people, according to Washington Post. And now, it is oozing into the United States. Experts have warned that temperature may reach 44 degrees Celsius in Florida, Texas and parts of Nevada. The punishing heat has already broken all-time high temperature records in Mexico multiple times. And researchers the National Autonomous University of Mexico have said that the country "will experience the highest temperatures ever recorded" in early June.

Meteorologists have attributed the extreme conditions to what is known as a heat dome.

What is a heat dome?

According to NASA's Earth Observatory, it is a weather phenomenon where a ridge of high pressure traps heat and air. 

A heat dome traps hot ocean air like a lid on a boiling pot and prevents cooler air from circulating. Hot air expands vertically into the atmosphere and high pressure pushes it toward the ground. It has nowhere to escape and compresses trapping even more heat underneath.

Heat domes and heatwaves happen at the same time, Gabriel A Vecchi from Princeton University told Time Magazine. A heat dome, however, intensifies a heatwave and causes it to persist.

Extreme heat spreading across the world

On Wednesday, a weather station in India's capital Delhi recorded a temperature of 52.9 degrees - the highest ever in the country. An investigation has been launched to determine if the Mungeshpur station's record reading was due to a sensor error or local factors.

In July 2022, temperature in the UK crossed 40 degrees Celsius for the first time. Then in China, a town recorded 52 degrees Celsius last year, the highest ever for the country.

In 2021, Sicily in Italy recorded 48.8 degree Celsius, the highest for Europe ever. The heat is rising in Antarctica too.

Urban Heat Island Effect

Compounding the effect of heatwaves is the urban heat island (UHI) effect. Urban areas tend to be significantly warmer than their rural counterparts due to human activities and modifications of land surfaces.

Factors contributing to the UHI effect include the high concentration of buildings, roads, and other infrastructures that absorb and retain heat. Moreover, the lack of vegetation and green spaces reduces natural cooling processes like evapotranspiration.