Weather

How changing climate affects turbulence in the sky

If you’ve flown recently or over the past few years, you may have noticed more turbulence on your flight. There’s reason to believe climate change could be the cause. The planet has warmed about one degree Celsius since the start of the Industrial Revolution and is increasing 0.2 degrees Celsius per decade, according to NASA.

Dr. Paul Williams, a professor of Atmospheric Science at the University of Reading in the United Kingdom says the temperature is also changing at different altitudes and it’s these changes that can lead to more clear air turbulence.

He says that at ground level, the arctic region is warming faster than any other region on Earth because of melting sea ice. The sunlight that used to get reflected into space, effectively cooling the temperature, is now getting absorbed by the ocean. This is reducing the north to south temperature gradient that drives the jet stream.

However, things look different at the altitude that planes fly. The tropical regions are warming faster, and this strengthens the temperature gradient at jet level. It’s the strengthening temperature gradient that is causing more wind shear aloft which causes more clear air turbulence.

Clear air turbulence is invisible. It can’t be detected by radar. It’s the kind of turbulence where you could be flying smoothly in sunshine and then suddenly, it starts bumping for no apparent reason.

Williams says there’s 15 percent more wind shear in the jet stream than 40 years ago based on satellite data. He and his team have been running atmospheric model simulations, too, that tell them the jet stream will likely become more sheared. They found this by turning up the amount of carbon dioxide in their simulation and it shows more wind shear at jet level. He says that there could be two to three times more turbulence by the period 2050 to 2080.

His study focuses mainly on trans-Atlantic routes in the winter season because it’s a busy flight corridor and the jet stream is typically stronger in the winter. However, Williams says that he expects things would look the same across North America, the North Pacific, and Europe.

There are turbulence forecasts used by pilots, but Williams says they’re only 80 percent accurate and he’s hoping his research can lead them to be 100 percent accurate.

He says planes may encounter two to three times more turbulence in the future and the main impact to the planes would be wear and tear. However, he says not to worry because planes are built to withstand turbulence and are routinely checked after flights.