Climate change and bigger carbon dioxide levels to blame
Several serious turbulence incidents have hit airlines in recent days, and climate experts say we can expect more “clear air turbulence” in the future.
A United Airlines flight coming in to land at Billings, Montana, was shaken by sudden turbulence, injuring two passengers and three flight attendants. A mother lost hold of her baby but it landed unharmed on another seat.
Shortly afterwards, a Cathay Pacific flight from San Francisco became a rollercoaster ride above Japan, hospitalising eight passengers and crew.
The kind of turbulence that strikes suddenly, when seatbelt signs are off, tends to be “clear air turbulence” where there are no clouds.
One of the main causes is the fast currents of air above the Earth called jet streams, which produce turbulence at the edges. They are aggravated by weather, especially in winter. Radar and acoustic sensors cannot detect clear air turbulence.
Computer models predict that climate change and greater carbon dioxide levels will speed up the jet streams, leading to more and more serious episodes by 2050 – a doubling of the frequency and a 10% to 40% increase in strength, according to the department of meteorology at the University of Reading in the UK.
[pictured: Clouds along a jet stream over Canada; image courtesy NASA]