Heat dome drives early summer heat wave across Europe, experts say
Scientists say a stalled high-pressure pattern is trapping heat over Europe as France, Italy, Spain and the U.K. face dangerous temperatures.
By Lucas Ferreira · Science & Environment Writer
3 min read
A stationary high-pressure system known as a heat dome is helping fuel an early summer heat wave across Europe, scientists told The Associated Press. The pattern matters because it can hold dangerous heat and humidity over populated areas for days, raising health risks in places less prepared for prolonged extreme temperatures.
Millions of people in France, Italy, Spain and the United Kingdom have faced exceptionally high temperatures this week, according to AP. Forecasters expect the heat to persist for several days, with temperatures reaching up to 104 degrees Fahrenheit, or 40 degrees Celsius.
How a heat dome forms
Mireia Ginesta, a research associate at the Climate Litigation Lab at the Smith School of Enterprise and the Environment, described heat domes as high-pressure systems that stall for several days and trap heat and moisture near the surface. She said they are linked to a northward bend in the jet stream, the fast-moving band of winds high in the atmosphere that helps steer weather systems.
Under high pressure, air sinks toward lower elevations, Ginesta said. As it descends, it compresses, and that process raises both pressure and temperature.
Jennifer Francis, a climate scientist at the Woodwell Climate Research Center, told AP that the dome describes the upper-atmosphere pattern, while the heat wave is the effect people experience at ground level. In other words, the jet stream setup helps create the conditions for the extreme heat felt across communities.
Europe faces limited cooling options
France has been hit hardest so far, according to AP. The country does not have widespread air conditioning, and its national weather service has placed about half of France under a red heat wave alert.
French authorities also have reported about 40 drowning deaths as people sought relief from the heat in water, AP said. Trains, concerts and sporting events have been canceled in France, and authorities have restricted public alcohol drinking.
Francis said Europe has faced more severe heat waves in recent decades, and many communities lack the cooling infrastructure needed to reduce the danger. She told AP that those conditions have contributed to deadly outcomes during recent extreme heat events.
Liz Bentley, chief executive of the Royal Meteorological Society and a meteorology professor at the University of Reading, said June temperature records are likely to be broken by wide margins. Her warning came as the heat wave continued early in the season, before the hottest part of summer in much of Europe.
Climate change increases the risk
Experts cited by AP said climate change is making heat-dome conditions more common and exposing more countries to dangerous heat. Francis said global warming shifts the range of temperatures a place can experience, making the hottest extremes more likely.
Bentley compared the effect to turning up the world’s thermostat. She said climate change is making heat waves more frequent, stronger and longer-lasting.
How people can reduce risk
Health precautions include drinking water, avoiding strenuous activity during the hottest part of the day, seeking shade and cooling off safely in streams, lakes or the ocean when available, according to AP.
Francis also pointed to overnight heat as a major concern. She said bodies need a chance to cool down at night, and without that relief, heat stress can build and affect health.
This story draws on original reporting from Phys.org.