vapor trails


vapor trails

A long trail of visible moisture left by an aircraft as it flies at high altitude through very cold air. The trails are formed by the condensation of water vapor in the exhaust gases leaving the engine. They appear at a slight distance behind aircraft exhaust. Their longevity can vary from a fraction of a second to a few minutes. The minimum flight level at which these trails occur is called the mintra/MINTRA level, which a meteorologist obtains from a tephigram. Also called contrails or exhaust trails.