Planes Create Weird Clouds—And Snow, Rain Fall Out
Airplanes, it turns out, can change the weather—at least at the hyperlocal scale, a new study says.
Scientists have studied hole-punch clouds since the 1940s and have long suspected that planes play a role in their formation. (See pictures of a potentially new type of cloud.)
Now, ice microphysicist Andrew Heymsfield and colleagues have found that aircraft really can create the odd clouds. Their research also uncovered something totally new: that aircraft can unleash precipitation by carving the cloud tunnels, which had never before been observed.
(Pictures: "Night Shining Clouds Getting Brighter.")
Clouds at a certain altitude and temperature—relatively common over western Europe and the U.S. Pacific Northwest, for example—are saturated with water droplets cooled to about 5 degrees Fahrenheit (minus 15 degrees Celsius).
Because the water in these clouds is so pure—with no particles around which vapor can