title: Formation and spread of aircraft-induced holes in clouds.
abstract: Hole-punch and canal clouds have been observed for more than 50 years, but the mechanisms of formation, development, duration, and thus the extent of their effect have largely been ignored. The holes have been associated with inadvertent seeding of clouds with ice particles generated by aircraft, produced through spontaneous freezing of cloud droplets in air cooled as it flows around aircraft propeller tips or over jet aircraft wings. Model simulations indicate that the growth of the ice particles can induce vertical motions with a duration of 1 hour or more, a process that expands the holes and canals in clouds. Global effects are minimal, but regionally near major airports, additional precipitation can be induced.
authors: National Center for Atmospheric Research (NCAR), Boulder, CO 80301, USA. heyms1@ncar.ucar.edu
authors: Andrew J
authors: AJ
authors: Heymsfield
authors: Gregory
authors: G
authors: Thompson
authors: Hugh
authors: H
authors: Morrison
authors: Aaron
authors: A
authors: Bansemer
authors: Roy M
authors: RM
authors: Rasmussen
authors: Patrick
authors: P
authors: Minnis
authors: Zhien
authors: Z
authors: Wang
authors: Damao
authors: D
authors: Zhang