As Europe Faces Heat Wave After Another, Scientists Predict More is to Come
By: Sarah Wang
For the past few months, Europe has faced blistering heat waves with temperatures soaring well above average. Two months ago, France had its hottest May ever recorded. Last month, France experienced another heat wave that affected its surrounding countries, Spain and Italy.
Now, countries all over Europe have been hit by triple-digit temperatures, wildfires, and droughts. This behavior seems to be a trend, scientists say. Europe’s temperatures are increasing more each summer than any other place on Earth, beating the Western United States in terms of heat waves.
An obvious reason for this drastic increase in temperature is global warming. Greenhouse gas emissions trap heat inside the Earth’s atmosphere leading to temperatures an average of two degrees Fahrenheit higher than the late 19th century.
However, Europe’s surroundings especially make it a “hotspot” for heat waves and droughts.
“The current scorching temperatures that reached into England and Wales on Monday were caused in part by a region of upper level low-pressure air that has been stalled off the coast of Portugal for days,” said Henry Fountain, New York Times journalist. “It’s known as a ‘cutoff low’ in the parlance of atmospheric scientists, because it was cut off from a river of westerly winds, the mid-latitude jet stream, that circles the planet at high altitudes.”
This low-pressure zone takes warm air from North Africa and transports it to Europe, pumping the air northwards to Europe. Dr. Kai Kornhuber, a researcher at Columbia University, took part in a study that linked Europe’s rising temperatures to a change in the mid-latitude jet stream.
Researchers found that many of Europe’s heatwaves took place when the jet stream temporarily split in two, causing the buildup of hot air in between the split streams.
The weakening of the Atlantic Meridional Overturning Circulation as the Earth heats up may also be causing the heat in Europe. A computer simulation published by Potsdam Institute for Climate Research’s Dr. Efi Rousi shows that as the current weakened, the atmospheric circulation change would lead to drier summers in Europe.
After one heat wave happens, more are likely to follow. Drought dries out the soil in the affected area, causing the sun to use its energy to heat the surface instead of evaporating the moisture in the soil.