Contrails – visible aviation induced climate impact

Abstract

Contrails are aircraft induced linear ice particle clouds. In ice-supersaturated air masses, contrails persist and develop into contrail cirrus. Aviation changes cloudiness also by soot emissions and other aerosols. In the global mean, contrail cirrus warms the atmosphere. The local warming induced by a contrail varies strongly relative to the global mean, and may be positive or negative, depending on aircraft, route, solar and Earth-atmosphere parameters. Here we summarize present knowledge on contrails with respect to aviation and atmospheric research.