Contrails
Contrails, short for condensation-trails, are man-made clouds formed when warm, moist exhaust air from jet engines cools to form ice crystals. While purist cloud spotters detest man’s intrusion into the romantic domain of clouds, they bring delight to the young at heart as they criss-cross the sky and are a useful weather forecasting tool for the more practically minded.
Usually, contrails will linger for a while then evaporate back into water vapour. If they hang about and spread out it is an indication of humid air at high altitudes which could mean there is bad weather on the way. There is speculation that contrails will hasten global warming by trapping heat in the atmosphere.
Usually, contrails will linger for a while then evaporate back into water vapour. If they hang about and spread out it is an indication of humid air at high altitudes which could mean there is bad weather on the way. There is speculation that contrails will hasten global warming by trapping heat in the atmosphere.