Sweltering Heat Domes Are Becoming More Common

Sweltering Heat Domes Are Becoming More Common

The term "heat dome" is gaining in popularity, and not because meteorologists like to be on trend. This meteorological phenomenon takes place when a high-pressure system in the mid to upper atmosphere pushes warm air down toward the Earth's surface and traps it there, leading to much higher temperatures. Meteorologists determine a heat dome's intensity with something called "geopotential height." Here's how it works: hot air is less dense than cold air and takes up more space, so they find where the atmosphere is a standard 500 millibars of pressure and measure that height. The higher this is, the more hot air there is to take up space, and the more intense the heat dome. Heat domes exceeding an extreme 6,000-meter geopotential height are very rare, happening only a handful of times in the last half century. But WeatherBell Analytics meteorologist Ryan Maue has found that these extreme heat domes have become much more frequent recently, with almost all of them occurring since 1983 and the overwhelming majority since 1990. Scientists believe our warming climate is to blame. We've collected some awesome videos on this topic. Watch them now to learn more.


Key Facts In This Video

  • 1

    A heat dome is a stagnant mass of hot, humid air up to a million square miles in size. Its low pressure bears down on air beneath it, creating a sealed-off dome of heat. (0:34)

  • 2

    Eventually, the dome breaks up, and the jet stream pushes it out to the ocean. (1:08)

  • 3

    There's no single incident that can prove or disprove global warming. It's an average effect. (2:32)

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