Clear-air Turbulence

Clear-air turbulence (CAT) is the turbulent movement of air masses in the absence of any visual cues such as clouds, and is caused when bodies of air moving at widely different speeds meet.

The atmospheric region most susceptible to CAT is the high troposphere at altitudes of around 7,000–12,000 metres (23,000–39,000 ft) as it meets the tropopause. Here CAT is most frequently encountered in the regions of jet streams. At lower altitudes it may also occur near mountain ranges. Thin cirrus cloud can also indicate high probability of CAT.

CAT can be hazardous to the comfort, and even safety, of air travel.

Read more about Clear-air Turbulence:  Detection, Factors That Increase CAT Probability, Effects On Aircraft

Other articles related to "turbulence":

Clear-air Turbulence - Effects On Aircraft - Wake Turbulence
... Wake turbulence is another dangerous type of clear-air turbulence, but in this case the causes are quite different to those set out above ... In the case of wake turbulence, the rotating vortex-pair created by the wings of a large aircraft as it travels lingers for a significant amount of time after the passage of the aircraft ... When this occurs, the lingering turbulence caused by the wake of the wing tips can deflect or even flip a smaller aircraft on the ground or in the air ...

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