Scientists Project Doubling To Quadrupling Of Clear-Air Turbulance On Routes Along Jet Streams In Next Few Decades
VIENNA—Scientists at the European Geosciences Union conference last week said there is growing scientific evidence that global warming is driving a big increase in dangerous clear-air turbulence, which is invisible from the cockpit and can surprise pilots and damage aircraft. Along some busy flight routes, turbulence is projected to “double or treble or quadruple over the next few decades,” said Paul Williams, a professor of atmospheric science and head of the weather research division at the University of Reading in the United Kingdom. “What we find … is that the jet stream regions in both the Northern and the Southern hemispheres are affected.”
As its name implies, clear-air turbulence can happen when there are no visible signs of a weather disturbance, often at or near the boundary of contrasting air masses, moving in different directions and at varying speeds. It can unexpectedly toss large airplanes up and down by several hundred feet, potentially damaging the airframe and injuring passengers and crew.
The increase of clear-air turbulence has been documented for a few years. Researchers are now starting to understand how and why it happens, which could help develop new ways to forecast and avoid it, especially when it involves the jet stream, strong rivers of air in the Northern and Southern hemisphere that steer weather systems and air masses from west to east. But looking at how climate change affects wind speeds in the upper atmosphere hasn’t proven very helpful in understanding clear-air turbulence, Williams said. Vertical wind shear—the difference in the speed and direction of winds at different altitudes—is a much more useful variable for the researchers.
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Climate models show that, under the most realistic greenhouse gas emissions scenarios, a “hotspot in the tropical upper troposphere will continue to grow, which means an even stronger midlatitude temperature gradient,” he said. That hotspot in the upper troposphere is an area of amplified warming resulting partly from water vapor feedbacks, as moist, hot air steams off the tropical oceans. That heat bulge is increasing the temperature gradient in areas near some of the busiest flight paths, including transatlantic routes.
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https://insideclimatenews.org/news/07052025/clear-air-turbulence-could-lead-to-bumpier-flights/