The climate crisis could be making transatlantic flights more bumpy, according to research into the impact of global heating on the jet stream. From a report: Jet streams are powerful currents of air at the altitudes which planes fly. They result from the air temperature gradient between the poles and the tropics, and reach speeds of up to 250mph (400kmph). They also sometimes meander. Researchers say previous studies of the speed and location of the fastest part of the north Atlantic jet stream have found only small changes over time, although there are signs it is slowly shifting northward. Experts say the lack of dramatic alterations is because climate change produces competing effects at different altitudes. The latest study, however, took a different approach. “Just because the speed isn’t changing, doesn’t mean the jet stream isn’t changing in other ways,” said Prof Paul Williams of the University of Reading, the lead author of the research.
His study, published in the journal Nature, looked at the change in wind speed with height, known as vertical shear. “The higher up you go, the windier it gets,” he said. Using three different datasets based on satellite observations, the team say they identified a 15% increase in vertical shear between 1979 and 2017, consistent with what would be expected from climate change. “The winds and the temperatures are in a certain kind of balance in the atmosphere,” said Williams. “The consequence is that it is impossible to change the temperature patterns without having an effect on the wind patterns.”
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