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
Famous quotes containing the words clear, air and/or turbulence:
“The forests are held cheap after the white pine has been culled out; and the explorers and hunters pray for rain only to clear the atmosphere of smoke.”
—Henry David Thoreau (1817–1862)
“By the roadside a hideous carrion, quivering
On a clean bed of pebbly clay,
Her legs flexed in the air like a courtesan,
Burning and sweating venomously,
Calmly exposed its belly, ironic and wan,
Clamorous with foul ecstasy.”
—Allen Tate (1899–1979)
“their eyes still fixed, hoping to find once more,
Being by Calvary’s turbulence unsatisfied,
The uncontrollable mystery on the bestial floor.”
—William Butler Yeats (1865–1939)