Never Miss Out On Another New And Exciting Article! The brightly coloured clouds have seen skies smeared with bright pinks, blues, yellows and greens. "These eye-catching rainbow-coloured clouds form in the Earth's stratosphere at around 70,000ft, way above where other clouds are normally found and in much colder air, around -78C. Unlike most other fast-moving cloud formations that occur much lower in the atmosphere, the aptly named mother of pearl clouds also seems to remain stationary in the sky as a result of their great height. In this article, we will focus on what nacreous clouds are, how they form, and what their characteristics are. Once the sun dips below the horizon, however, the clouds start to display bright luminous colors. Yes, in addition to the major naming conventions for clouds based on altitude and characteristics, there are also a variety of other Latin terms used to describe clouds. They are long, curved, and fibrous-looking. Sometimes, lenticular clouds are mistaken for UFOs because of their unusual disk shapes. Mackerel skies are the result of altocumulus or cirrocumulus clouds forming a distinctive pattern that looks like the scales on a mackerel fish's back. It is these high altitudes that allow them to remain illuminated for some period after sunset. These clouds, often appearing as one or more lens shapes stacked one on top of another, have been given many other names, too, including cap cloud, banner cloud, rotor cloud, crest cloud, foehn cloud, table. #nacreousclouds pic.twitter.com/kNRTG9mxix, More of those crazy clouds this morning #nacreousclouds #northumberland #StormHenry pic.twitter.com/bfeIEzr1jb. Nacreous clouds (Type II PSCs) glow brightly with vivid iridescent colours. They are usually seen at twilight and have a bluish or silvery color, sometimes flecked with red. The shades come from ice crystals refracting the sun's rays to give the unusual effect. ... even during winds gusting as much as 150 miles (241 kilometers) per hour. As the pearl grows, the inside of the shell also gets covered with nacre. so incredibly beautiful. In terms of annual average days when they were under overcast skies, the 10 cloudiest cities in the United States are as follows: 1. First studied during World War II, when there was a concern that contrails would give away the positions of B29 aircraft, contrails are now of interest to climatologists who worry about their effects on global warming. This phenomenon can be best observed within the first two hours after sunset when rays of light illuminate the clouds from below the horizon. Nacreous (or mother of pearl) clouds are rare occurrences that appear almost exclusively over the Arctic regions and are seen by very few people in selected areas as a result. Save my name, email, and website in this browser for the next time I comment. It is from their unique color pattern that the name "mother of pearl clouds" originated. Express. Polar stratospheric clouds (PSCs) are clouds in the winter polar stratosphere at altitudes of 15,000–25,000 m (49,000–82,000 ft). Likewise, how are storm clouds formed? Moist air circulates above the cloud, and water vapor condenses, evaporating as it moves downwind and toward the ground. These high altitude clouds form only at very low temperatures help destroy ozone in two ways: They provide a surface which converts benign forms of chlorine into reactive, ozone-destroying forms, and they remove nitrogen compounds that moderate the destructive impact of chlorine. Scientists are also concerned about the other chemicals in jet exhaust that could aversely affect chemical processes within the troposphere and lower atmosphere. When clouds do form at high altitudes above the surface, the ice crystals in nacreous clouds are much smaller than those that form in normal cloud formations. This type of PSC is also referred to as nacreous (/ˈneɪkriəs/, from nacre, or mother of pearl, due to its iridescence). One main type of PSC is made up mostly of supercooled droplets of water and nitric acid and is implicated in the formation of ozone holes. How do Nacreous clouds form? What a lovely start to the day. What Is The Difference Between A Hurricane, Typhoon, And Cyclone? (The reason for the "mother of pearl" association and resulting name will be explained in more detail later in this article.). Nacre is the substance responsible for the iridescent rainbow and pastel colors known as "mother of pearl" found in certain mollusk shells. "Usually it is far too dry at this height for clouds to form, but during the polar winter the temperature can drop low enough to promote the clouds’ development.”. Their sheet-like forms slowly undulate and stretch as the waves evolve. The mother of pearl clouds are most likely to be seen in Scandinavia and northern Canada. newspaper archive. For the remainder of this article, the name "nacreous clouds" will be used to describe this phenomenon. Water vapor condenses and forms cumulus clouds. More technically known as cirrus fibratus clouds, mare's tails get their name from their appearance. Before looking at their origin and formation, one first needs to establish a clear and concise definition of what nacreous clouds are: Nacreous clouds are polar stratospheric clouds that occur high in the stratosphere moments after sunset in regions close to or in the Arctic Circle.They are recognized by their unique display of iridescent colors and patterns. The visibility of the colors may be enhanced with a polarising filter. The word "nacreous" in nacreous clouds is derived from the word "nacre." What makes nacreous clouds so unique is not only their rare occurrence but also the wide array of colors they display that has a uniquely surreal look to them. 22 Interesting & Important Facts About The Weather You Should Know, Rainiest Cities In The World: 12 Places With The Highest Rainfall In The World, Windiest Place On Earth… A Look At Locations Around The Globe Experiencing Extreme Winds. Photos of the impressive skies have been posted on Twitter. A number of people were fooled into thinking that they had seen the aurora borealis, but the current conditions rule out sightings of the Northern Lights in the UK. Autumn Skies Online Pty Ltd is compensated for referring traffic and business to these companies.”. This phenomenon is called mother of pearl clouds, a sporadic cloud formation that appears in regions within and bordering the Arctic Circle. For instance, studies have shown that where contrails are present there is an increase in the formation of more cirrus clouds. They have iridescent colours but are higher and much rarer than ordinary iridescent clouds. Nacreous clouds are clouds that occur at elevations of 12 to 20 miles (19 to 32 kilometers) high (rarely at lower altitudes) and look like cirrus or altocumulus lenticularis clouds. “This site is owned and operated by Autumn Skies Online Pty Ltd, a limited liability company headquartered in Somerset West, South Africa. [10], Antarctic stratospheric cloud (nacreous clouds), "Polar stratospheric clouds / Observations", United States Environmental Protection Agency, "Polar stratospheric cloud microphysics and chemistry", "Polar Stratospheric Clouds Above Spitsbergen", Alfred Wegener Institute for Polar and Marine Research, "Nitric acid and water PSC, International Cloud Atlas", "Nacreous and Polar Stratospheric Clouds", "Scientific Assessment of Ozone Depletion", "Nacreous PSC, International Cloud Atlas", "Upper atmospheric clouds, International Cloud Atlas", Polar Stratospheric Clouds Above Spitsbergen, https://news.yahoo.com/s/ap/20060801/ap_on_sc/antarctica_clouds_4, http://www.cnn.com/2006/TECH/science/08/01/antarctica.clouds.ap/index.html, Nitric acid and water polar stratospheric clouds, https://en.wikipedia.org/w/index.php?title=Polar_stratospheric_cloud&oldid=971773373, Articles with dead external links from September 2018, Creative Commons Attribution-ShareAlike License. [1][4], PSCs are classified into two main types each of which consists of several sub-types, Only Type II clouds are necessarily nacreous[1] whereas Type I clouds can be iridescent under certain conditions, just as any other cloud. Privacy Policy Typically, these clouds are formed near mountainous regions, where air is moving in a "standing wave" pattern. I am referring to a rare, unique, as well as breathtaking phenomenon that occasionally occurs in the skies above the Arctic Regions. Asperitas clouds are so unusual, they weren't officially recognised until June 2015. As the sun continues to sinks further below the horizon, the bright luminous clouds slowly change into a mixture of pink, green, and mostly pastel-colored formations, which contributes to the the surreal effect that is so unique to nacreous clouds. These rare clouds, sometimes called mother-of-pearl clouds, are 15 – 25km (9 -16 miles) high in the stratosphere and well above tropospheric clouds.         Iridescence is an optical occurrence that causes objects to display vivid rainbow-like colors. Yet, their appearance and surreal color displays are so unique and captivating that they are better known than there rarity suggests, especially in meteorological circles. They are also known for their rare appearances, which are also mostly limited to polar regions. The air over the polar regions is normally very dry, making cloud formation a very rare occurrence. These clouds are more commonly known as nacreous clouds. [2] The other main type consists only of ice crystals which are not harmful. Astoria, OR, and Quillayote, WA: both 240 days, Altocumulus lenticularis (commonly called lenticular) clouds are sometimes called "flying saucer clouds" because they bear a strong resemblance to UFOs that have been reported over the years. Autumn Skies Online Pty Ltd also participates in affiliate programs with Clickbank, CJ, ShareASale, and other sites. The stratosphere is very dry; unlike the troposphere, it rarely allows clouds to form. In rare cases, they are attached to the nacreous clouds. Mammatus clouds over Tulsa, Oklahoma. A Division of Autumn Skies Online (Pty) Ltd Disclaimer The mother of pearl clouds are most likely to be seen in Scandinavia and northern Canada. But aside from being nice features in the sky, clouds play a role in knowing the intensity and severity of a weather system. #RainbowClouds #edinphoto pic.twitter.com/F9gjb76Mh9, Nacreous-tastic over Edinburgh this morning pic.twitter.com/Vzhdvxvm9u, Rare Nacreous clouds otherwise known as polar stratospheric clouds are being spotted across the island. These temperatures can occur in the lower stratosphere in polar winter. It is these smaller ice crystals that allow the sunlight to be scattered and refracted in such a way to produce the vibrant iridescent colors that are so unique to this occurrence. A peculiar property of these clouds is that they tend to remain stationary, even during winds gusting as much as 150 miles (241 kilometers) per hour. Contrails can turn into cirrus clouds if the air is close to being saturated with water vapor. Type I clouds have a generally stratiform appearance resembling cirrostratus or haze. Early risers across the northern half of the UK earlier this week were treated to the rare sight of nacreous clouds shimmering in the dawn sky. They are best observed during civil twilight, when the Sun is between 1 and 6 degrees below the horizon, as well as in winter and in more northerly latitudes. In the case of nacreous clouds, the colors can vary from luminous and vivid, to the familiar pastel colors that are so unique and contributes to the surreal effect of this phenomenon.