Our Amazing Planet EarthLists about the beautiful, fascinating, sometimes terrifying features and living things that naturally developed on this spinning rock we all call home.
Updated August 10, 2020 6.5k votes 955 voters 28.2k views
There is a long history of man looking up into the sky and seeing something so strange that the only option was to declare it extraterrestrial. Who knows how many stories these weather anomalies spawned? Green glowing lights dancing on the horizon, iridescent glowing night clouds, sparkling moon-rainbows and odd, colorful halos in the mist. Water and light and wind can playfully mix together all kinds of beautiful, magical creations.
Which of these rare atmospheric anomalies have you seen?
This unusual weather event is thermodynamically identical to a normal thunderstorm, but with snow instead of rain and the top of the thunderhead cloud low. As with a normal thunderstorm, hail may also fall. Thundersnow is often a part of a severe winter storm or blizzard with winds capable of being above tropical storm force. As a result, visibilities are frequently under 1⁄4 mile with extreme wind chills that can result in frostbite. There is also a greater likelihood that thundersnow lightning will have a positive polarity, which is associated with a greater destructive potential than the more common negatively-charged lightning.
"Aurora Borealis? At this time of year, at this time of day, in this part of the country, localized entirely within your kitchen?" - Superintendent Chalmers
This atmospheric phenomena might be rare, but it's so spectacular that - unlike the rest of this list - everyone has heard of it. Also known as the Northern Lights or Southern Lights, this amazing light display is predominantly seen in the high-latitude regions of the Earth. These light shows occur when the magnetosphere is disturbed by solar wind. Charged particles in the form of electrons and protons change trajectory and precipitate into the upper atmosphere where their energy is lost.
Auroras can be seen at lower altitudes as well, but present from further away, illuminating the poleward horizon as a greenish or reddish glow.
The real name for this rare weather phenomenon is a circumhorizontal arc. These are caused by light passing through wispy, high-altitude cirrus clouds. They can occur only when the sun is very high - more than 58° above the horizon - in the sky and along the mid-latitudes in the summertime. In order for the conditions to be right, the hexagonal ice crystals that make up these cirrus clouds must be shaped like thick plates with their faces parallel to the ground. When light passes through, it refracts, or bends, in the same way that light passes through a prism. If all the crystals are lined up just right, the whole thing lights up like a rainbow.
This amazing cloud formation is particularly spectacular, but also usually means big storm activity. They will often come out of the base of a cumulonimbus - or thunderhead - cloud and are generally indicative of a dangerous storm. They appear as smooth, ragged or lumpy lobes and may even be somewhat translucent. They are usually composed of ice but can also be a mixture of ice and water and in some cases entirely made of water. They are formed by cold air sinking down through the cloud above and cupped by rising convective warm air. These clouds are usually the lumpy harbingers of very severe weather.
Also called a 'mock sun', the sun dog is a concentrated patch of sunlight that often forms in pairs 22° to the left or right on either side of the sun when conditions are right. They are basically a kind of halo similar to the circumzenithal arc. When high and cold cirrus or cirrostratus clouds contain plate-shaped ice crystals - these crystals act as prisms, bending the light rays passing through them with a minimum deflection of 22°. As the crystals gently float downwards with their large hexagonal faces almost horizontal, sunlight is refracted horizontally, and sun dogs are seen to the left and right of the Sun. Larger crystals wobble more, and thus produce taller sundogs. They tend to be red-colored at the side nearest the Sun; farther out the colors grade through oranges to blue. However, the colors overlap considerably and so are muted, never pure or saturated.
For many years, this scary-movie-lookin' cloud did not have a classification. It was nameless. In 2014, after being first proposed as an officially named occurrence by Gavin Pretor-Pinney of the Cloud Appreciation Society, it was officially entered into the International Cloud Atlas. These apocalyptic looking clouds tend to be low-lying and are caused by weather fronts that create undulating waves in the atmosphere. Varying levels of illumination and thickness can create a truly dark and dramatic cloud cover. They are mostly seen on the Great Plains of the US following thunderstorms.
