Aircraft Contrail Cirrus (Contrail)
Contrails are really man made clouds, for if aircraft were not flying in the upper atmosphere they would not be created. The Contrail is formed as it's name suggests from condensation, it is in fact a condensation trail (contrail). as the exhaust exits the aircraft engines the small amount of moisture within the exhaust condenses into water particles which then freeze in the cold upper air. The contrail will seem to follow the aircraft with one trail per engine but these soon combine into a sort of elongated cirrocumulus. The contrail spreads in the slipstream of the aircraft or the upper winds, persisting or disappearing after a sort time this will depend on the relative humidity and height of the aircraft.