Physics

20 Things You Didn't Know About... Clouds

4  So much for People Power. After reviewing 40 years of cloud-seeding efforts in an area north of Israel, researchers at Tel Aviv University have concluded that seeding doesn’t actually produce additional precipitation (pdf).

12  Highest of them all: 50 miles up, noctilucent, or “night shining,” clouds glow an eerie bluish white. They are invisible by day, but after sunset they catch solar rays shining from far below the horizon.
13  Noctilucent clouds seemed to first appear after the 1883 eruption of Krakatoa and are now a common sight.

18  In 1959 Lt. Col. William Rankin was flying his F-8 fighter jet over a cumulonimbus when the engine failed. He parachuted out and spent the next 30 minutes bounced around inside the storm. Amazingly, he survived.
19  In 2007 German paragliding champion Ewa Wisnierska experienced “cloud suck.” While gliding under a cumulonimbus, she was pulled upward to 32,000 feet. She blacked out due to lack of oxygen but regained consciousness at roughly 23,000 feet.

Image: A lenticular cloud over the Tararua Mountains in the North Island of New Zealand. Courtesy: NASA