2007-03-12 07:11:32 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Geography
If you watch the planes at their cruising altitude of ca. 30.000 feet, you should see their contrails, no matter where you are located.
Perhaps when you see the planes from the UK where you live they were at cruising altitude, and when you saw them in South Africa at the location where you were staying, they weren't.
The planes were just flying lower, being closer to an airport, that would explain the absence of their contrail.
2007-03-15 18:32:49 · answer #1 · answered by McMurdo 3 · 0⤊ 0⤋
"Contrails form through the injection of water vapor into the atmosphere by exhaust fumes from a jet engine. If there is sufficient mixing between the cold upper tropospheric air and the hot exhaust gases to produce a state of saturation, ice crystals will develop."
So, I would assume from this that the warmer air over South Africa is less conducive to this phenomena.
2007-03-12 08:23:53 · answer #2 · answered by Yahzmin ♥♥ 4ever 7 · 0⤊ 0⤋
lower moisture in the air.
2007-03-12 07:19:15 · answer #3 · answered by jarrow t 3 · 0⤊ 0⤋
no planes flying over head.
2007-03-12 07:14:10 · answer #4 · answered by Jon S 4 · 0⤊ 0⤋