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)
“People fall out of windows, trees tumble down,
Summer is changed to winter, the young grow old
The air is full of children, statues, roofs
And snow. The theatre is spinning round,
Colliding with deaf-mute churches and optical trains.
The most massive sopranos are singing songs of scales.”
—Wallace Stevens (1879–1955)
“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)