Séminaire
Currently, ice production by aircraft is conventionally considered to occur as contrails, which typically form behind jet aircraft as a result of engine combustion when the air temperature is ~40°C and below, characteristic of cirrus-forming (ice-cloud) conditions. Recent evidence points to the extension of aircraft effects to temperatures where the warmer midlevel clouds are observed. When altocumulus are thin and occur at temperatures between about -10 and -35°C, aircraft can produce the peculiar and striking formations called “hole punch” and “canal” clouds, which have the appearance of dissipation trails. I will discuss observations of these features, why they can spread and persist for many
hours, and possibly important implications.
Thibaud Thonat
thibaud.thonat@lmd.polytechnique.fr