Heat Dome

News: A US city has recorded the highest temperatures as high as 46-degree Celsius part due to the historic heatwave that lasted as a result of a phenomenon referred to as a “heat dome”.

What is a Heat Dome?

  • To understand what causes a heat dome, one should liken the Pacific Ocean to a large swimming pool in which the heater is turned on.
  • Once the heater is on, the portions of the pool close to the heating jets will warm up faster and therefore, the temperature in that area will be higher.
  • In the same way, the western Pacific ocean’s temperatures have increased in the past few decades and are relatively more than the temperature in the eastern Pacific.
  • This strong change in ocean temperature from the west to the east is what a team of scientists believe is the reason for the heat dome. This occurs when the atmosphere traps heat at the surface, which encourages the formation of a heatwave.
  • To compare, the reason that the planet Venus is the hottest in the Solar System is that its thick, dense cloud cover traps the heat at the surface, leading to temperatures as high as 471 degrees Celsius.
  • Those living without an air conditioner see the temperatures of their homes rising to unbearably high, leading to sudden fatalities. The trapping of heat can also damage crops, dry out vegetation and result in droughts. The sweltering heat wave will also lead to rise in energy demand, especially electricity, leading to pushing up rates.
  • The heat domes can also act as fuel to wildfires, which destroys a lot of land area in the US every year.
  • The weather scientists have been highlighting the effects of climate change on more extreme heat waves.
  • According to a 2017 NOAA (National Oceanic and Atmospheric Administration) survey, average US temperatures have increased since the late 19th
  • However, Scientists are usually wary of linking climate change to any contemporary event mainly because of the difficulty in completely ruling out the possibility of the event having been caused by some other reason, or being a result of natural variability.

Heat Wave:

  • A heat wave is a period of abnormally high temperatures, more than the normal maximum temperature that lasts for more than two days.
  • Heat waves typically occur between March and June, and in some rare cases even extend till July.
  • Heat waves can occur with or without high humidity and have the potential to cover a large area, “exposing a high number of people to hazardous heat.”

Impact on Humans (Wet-bulb temperature):

  • As long as the body is producing sweat, which is then able to evaporate quickly, the body will be able to remain cool even under high temperatures. Wet-bulb temperature (WBT) is a limit that considers heat and humidity beyond which humans cannot tolerate high temperatures.
  • Temperatures beyond WBT can cause heat related illnesses including heat stroke, heat exhaustion, sunburn and heat rashes. Sometimes these can prove fatal.