Climate Matters: More turbulence in a changing climate

If you have noticed more shaking and turbulence on your flights in recent years it might not be all your imagination. New studies suggest that planes are encountering more turbulence even in clear skies and this could be due to shifting weather patterns.

Turbulence is the irregular movement of air due to air currents and eddies and is one of the hardest weather patterns to predict. It occurs in the atmosphere on small and large scales from a wide variety of sources. Friction between the ground and the air constantly produces turbulence as winds wrap around structures and irregular terrain. Thunderstorms and fronts also cause turbulence far above the surface, which is why pilots try to avoid areas of active weather. But turbulence also happens in clear air which can be more of a problem.

Clear air turbulence occurs in the upper troposphere and is not associated with thunderstorms. This type of turbulence can be found near mountains or in jet streams. Planes will commonly fly with the jet streams to speed things along but this can open them up to more encounters with turbulence. Clear air turbulence is potentially on the increase in busy travel routes over North America and the Atlantic with studies showing the most severe clear air turbulence increasing over 50% in the last 40 years. This is thought to be the result of better technology and more chaotic and unpredictable weather patterns in a changing climate.

Nick Anderson, a former Royal Air Force pilot with nearly 50 years of experience flying, states that turbulence is mostly just a nuisance. He says encounters with turbulence are common on any flight, but anything worrisome is much rarer. Flights are bumpy during takeoff and landing but this is usually nothing to worry about with everyone fastened in. Nick says it's at cruising altitudes where there's more concern for injuries, especially for crew members. This is also where unpredictable clear air turbulence can occur, but Nick says severe instances of turbulence on his flights have been few and far between. "It's probably less than the number of fingers on my hand."

While turbulence may be on the rise technology and monitoring also continue to improve and enhance safety. There have been no reported deaths this century for any American airline due to turbulence, with the most recent occurring in 1997 as a United Airlines flight encountered rough turbulence flying from Tokyo to Honolulu.