posted on Sep, 15 2013 @ 03:30 PM
why do they expand and form clouds? Why do they not just dissipate?
The same reason why clouds expand and form larger clouds, or dissipate.
This depends on the humidity at the altitude that the planes are flying at. If it's humid, contrails will persist and spread out depending on how
humid it is. Same thing with clouds. On a very humid day, clouds can form out of nothing and spread out into large storms rather quickly.
When the air is dry, contrails will dissipate. Sometimes clouds will dissipate when drier air moves in.
The formation and persistence of contrails is dependent on the temperature and humidity at the altitude that the plane is flying at, regardless of the
temperature and humidity at ground level.
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