Q. Why is this in news?
Parts of Canada and USA are reeling under severe heat wave caused due to a heat dome.
Q. What Is A Heat Dome?
A heat dome occurs when the atmosphere traps hot ocean air like a lid or cap.
- The scorching heat is ensnared in what is called a heat dome.
- High-pressure circulation in the atmosphere acts like a dome or cap, trapping heat at the surface and favoring the formation of a heat wave.
Q. What are its causes?
- This happens when strong, high-pressure atmospheric conditions combine with influences from La Niña.
- This creates vast areas of sweltering heat that gets trapped under the high-pressure “dome“.
- The main cause is a strong change (or gradient) in ocean temperatures from west to east in the tropical Pacific Ocean.
Q. How is it created?
- In a process known as convection, the gradient causes more warm air, heated by the ocean surface.
- This rises over the western Pacific, and decreases convection over the central and eastern Pacific.
- As prevailing winds move the hot air east, the northern shifts of the jet stream trap the air.
- Thus winds move it toward land, where it sinks, resulting in heat waves.
Q. What are the Impact of a heat dome?
- Lead to a sudden rise in fatalities due to extreme heat like conditions.
- Trapping of heat can also damage crops, dry out vegetation and result in droughts.
- The heat wave will also lead to rise in energy demand, especially electricity, leading to pushing up rates.
- Heat domes can also act as fuel to wildfires, which destroys a lot of land area in the US every year.
- Heat dome also prevents clouds from forming, allowing for more radiation from the sun to hit the ground.