a cloud is an aerosol comprising a visible mass of minute liquid droplets, frozen crystals, or particles suspended in the atmosphere above the surface of a planetary body.
1. Clouds look like they weigh little more than a tuft of cotton, but they’re heavier than they look.
2. Your average cumulus (fair weather) cloud can weigh more than a million pounds, and a vivacious thunderstorm can pack billions of pounds of water in one tiny part of the sky.
3. While most clouds we see are made up of tiny liquid water droplets, there is one common type of cloud that’s made of ice called the cirrus.
4. Strong winds then shred these clouds apart, giving them their iconic wispy appearance.
5. In about 340 BC the Greek philosopher Aristotle wrote Meteorologica, a work which represented the sum of knowledge of the time about natural science, including weather and climate. He reach that point from observing… clouds!
6. After centuries of speculative theories about the formation and behavior of clouds, the first truly scientific studies were undertaken by Luke Howard in England and Jean-Baptiste Lamarck in France.
7. There’s a type of cloud called “virga,” that evaporates before reaching the ground.
8. Some clouds can occur as a result of human activity. Contrails form from an airplane’s hot, moist jet exhaust condensing in the extremely cold air of the upper atmosphere. These cirrus clouds can immediately dissipate or linger for hours depending on how much moisture is present.
9. Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology.
10. Supercell, or motherboard thunderstorms are dangerous storms that have a strong updraft and rotation. These storms can be very long-lived and can produce significant damage in many communities. “Storms possessing this structure have been observed to generate the vast majority of long-lived strong and violent (F2-F5) tornadoes, as well as downburst damage and large hail,” according to the National Weather Service.
11. One of the most impressive clouds is the anvil cloud, and it occurs when a thunderstorm’s updraft hits the tropopause, usually the point at which air is neutrally buoyant and it can no longer rise on its own.
12. The anvil cloud usually tends to look like an umbrella.
13. There are certain absolutely stunning clouds called shelf clouds. These formations roll across the horizon like a shelf or a wedge suspended just above the surface, immediately preceding heavy rain and wind. They could also be decribed as waves of some sort.
14. Shelf clouds form as a result of rain-cooled air descending from a thunderstorm and hugging the ground like a bubble. This creates an outflow boundary, which acts like a mini cold front scooping up warm air ahead of it. The shelf cloud forms at the ridge of the pool of cold air, creating a striking scene.
15. When moist, warm air rises to a cooler elevation, water condenses onto microscopic “seeds” like dust, ash, or bacteria. Water + seeds + updraft = clouds.
16. Nacreous clouds, or “mother of pearl” clouds, appear iridescent because of their ultrafine ice crystals, which form 10 to 15 miles up in the stratosphere.
17. Unfortunately, nacreous clouds also support chemical reactions that convert benign chlorine-containing molecules into a form that destroys Earth’s ozone layer.
18. A halo is a spectacular sight that occurs when sunlight or moonlight scatters through the ice crystals that make up a thin layer of cirrus clouds covering the part of the sky directly between the observer and the celestial body. Most halos completely encircle the Sun or the Moon, but depending on the shape or size of the ice crystals, the halos can be partial, inverted, or appear on different sides of the sky.
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.
20. A wall cloud is a cloud that is lowered from a thunderstorm, forming when rapidly rising air causes lower pressure below the storm’s main updraft. “Wall clouds can range from a fraction of a mile up to nearly five miles in diameter,” according to the National Weather Service.
21. A funnel cloud is a rotating column of air (visible due to condensation) that does not reach the ground.
22. If a funnel cloud reaches all the way to the ground then it is classified as a tornado.
23. Fog is simply a stratus cloud that forms at the surface. Freezing fog is fog that forms when temperatures are below freezing, consisting of supercooled water droplets that don’t have a nucleus to allow them to freeze into ice crystals.
24. Diamond dust, on the other hand, is fog that forms into ice crystals instead of water vapor.
25. This rare event occurs when the air is so cold (usually below 0°F) that water vapor deposits onto tiny particles in the air, creating suspended ice crystals that float around like snow. Visibility usually doesn’t drop much during diamond dust events, leading to a phenomenon that looks like light snow falling on a brilliantly clear day.