“Global warming is faster at the poles,” Faranda said, “and it’s melting ice and it’s also warming differently in oceans and on continents.”
As global warming jars climatic patterns, it affects the jet streams, he said.
Williams, the University of Reading scientist, was “the first to understand that if the jet stream is affected, then turbulence in the jet stream is affected, and therefore flight operations are affected,” Faranda said.
In his EGU presentation, Williams said it’s important to look at vertical wind shear because the signal in the data is much stronger compared to the noise.
“Why do we care about stronger wind shear? Well, of course, it’s because we fly through it,” he said, showing a photo of a grounded jet plane that lost an engine in severe clear-air turbulence. The data shows there has been a 55 percent increase of severe air turbulence since the 1970s, he added.
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.
If rapid warming continues, Williams said, studies show vertical wind shear could increase 29 percent by 2100, or 17 percent if global emissions are halved by mid-century and keep dropping.
“This, of course, means a lot more turbulence in not that many years from now,” he said.
Faranda added that his own experiences and research on clear-air turbulence won’t keep him from flying. New measurements by weather instruments and greater awareness of the potential for such turbulence will help keep most flights safe, and changes to wing design and plane construction could make them less vulnerable, he added.
“In principle, you can fly through these areas without consequences in most cases,” Faranda said. But with projections for more intense and frequent turbulence, it’s important to maintain observation programs, he added.
“With the new global political situation, there is a lot of talk of reducing instruments for monitoring the weather and the climate, and this would produce worse weather forecasts,” he said. And fewer weather observations will likely lead to shakier flights.
This story originally appeared on Inside Climate News.
