Aircraft increase the chances of snow or rain when they punch holes in clouds after taking off.

Airplanes can influence local weather when they take off and land.  Aircraft increase the chances of snow and rain during take off and landing, according to a  new study, published in the ‘Science’ journal. The finding is based on satellite images of clouds around airports.

The phenomenon occurs when aircraft smash through clouds containing “supercooled” water — or water that exists as droplets of liquid at temperatures of minus 10C or below, say the researchers. As an airplane passes through a cloud, air behind the wings and propellers expands and cools rapidly. These sudden drops in temperature can be enough to freeze droplets of super-cooled water, turning them into ice crystals.

Over time, ice crystals grow and affect neighboring drops of water — creating a hole in the cloud that expands for several hours and increasing the chances of snow or rain on the ground underneath. Dr Andrew Heymsfield of the National Center for Atmospheric Research in Boulder, Colorado, said aircraft increased the chances of snow when they punched holes in clouds after taking off and when they created ‘canals’ in clouds when descending.

“Whether an airplane creates a hole or a canal in the clouds depends on its trajectory. When they climb through a super-cooled cloud layer, they can just produce a hole. But when they fly level through the cloud layer, they can produce long canals,” he said.

Via Times of India