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Focused crawls are collections of frequently-updated webcrawl data from narrow (as opposed to broad or wide) web crawls, often focused on a single domain or subdomain. ||||| A volutus, or roll cloud, photographed in Szprotawa, Poland. This type of cloud was just added as a new species in the 2017 International Cloud Atlas. 
  
 A dramatically turbulent cloud formation called asperitas and the bizarrely cylindrical roll cloud are among the newest additions to the international handbook for cloud identification. 
  
 The World Meteorological Organization has released a new, digitized version of its "International Cloud Atlas," the global reference book for meteorologists and skywatchers alike. It's the first update for the atlas since 1987 and the first version to be fully web-based. The release also marks a red-letter day for amateur enthusiasts in the Cloud Appreciation Society, who get the satisfaction of seeing the asperitas cloud that they discovered become an official scientific category. 
  
 "It is a new classification of cloud, with a chaotic, turbulent appearance, that was proposed by the Cloud Appreciation Society back in 2008, based on photographs sent to us from members all around the world," the organization posted on its blog. "It is a classic example of citizen science, in which observations by the general public, enabled by the technology of smartphones and the Internet, have influenced the development of this most official of classification systems." [Gallery: The Craziest Clouds Ever] 
  
 The cloud atlas' classification system is not for the faint of heart. There are 10 basic "genera" of clouds, most of the names of which would be familiar to schoolchildren: cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, stratocumulus, stratus, cumulus and cumulonimbus. 
  
 Within each genera are species, which describe the internal structure of the shape of clouds. A lenticularis cloud, for example, is a flattened pancake shape that looks a bit like a giant UFO. Each type of cloud can only have one species, but the same species types are present in multiple different genera of clouds. 
  
 An image of a photometeor halo included in the new International Cloud Atlas. Halos are caused by light reflecting or refracting off tiny ice crystals suspended in the atmosphere, according to the Atlas. Credit: WMO International Cloud Atlas/Claudia Hinz, DMD 
  
 Next, the classification system includes varieties of clouds, which describe the clouds' transparency and arrangement. A single cloud can have multiple varieties, except in the case of opacus (opaque) clouds varieties and translucidus (translucent) varieties, which are mutually exclusive: One doesn't let any sun through, and the other does. [See Photos of a Various Cloud Types] 
  
 Thus, a standard cloud identification might look something like "altocumulus stratiformis translucidus perlucidus undulates" — an altocumulus cloud arranged in a thin sheet (stratiformis) that is translucent to sunlight, has small gaps allowing blue sky to show through (perlucidus) and which has wavy features (undulates). 
  
 The cloud atlas update doesn't alter any of the basic classifications for clouds, but it does add several new twists. The roll cloud, known as the volutus, is defined as a new species of cloud. These horizontal, cylindrical clouds form where descending cold air pushes warm, moist air upward. Under the right wind conditions, the atmospheric turbulence condenses into a tubular cloud that seems to roll across the sky. 
  
 An undulating asperitas cloud, photographed at Shorewell Park in Tasmania, Australia, at 7:48 a.m. local time on Feb. 20, 2004. Credit: WMO International Cloud Atlas/ © Gary McArthur 
  
 The atlas also adds five new "supplementary features" to its classification system. Supplementary features are unusual parts of, or attachments to, clouds. The wave-like undulations of the undersides of clouds, dubbed "asperitas," are among these new features. Another is "cavum," known colloquially as a hole-punch cloud because the cloud has a large circular gap through which the sky can be seen. A "cauda" is a horizontal feature that extends like a tail from a cloud. "Fluctus" features are wave formations that look like something a cartoon surfer would ride; they're commonly known as Kelvin-Helmholtz waves and are caused by wind shear. Finally, "murus" features, or wall clouds, are familiar to any storm chaser for their role in the formation of tornadoes. 
  
 The other main changes to the atlas are the addition of a new accessory cloud, or a cloud that accompanies another, larger cloud, and the establishment of five new special clouds, which describe unusual cloud formation circumstances. The new accessory cloud type is called "flumen" and describes a low cloud associated with severe supercell storms. 
  
 The five new special clouds are: cataractagenitus, describing clouds that develop from the spray of large waterfalls; flammagenitus, describing clouds formed under the influence of wildfires; homogenitus, describing clouds formed by human activities, such as airplane contrails; silvagenitus, describing clouds formed under the influence of moisture from respiring trees; and homomutatus, describing clouds originally made by humans that gradually transform into more natural-looking forms, like a contrail that eventually spreads in the wind. 
  
 The cloud atlas is available online and will be official unveiled today (March 23) for World Meteorological Day. 
  
 Original article on Live Science. ||||| 00:50 New Cloud Types Added Asperitas and murus are just two of the names you'll see among several new classifications added to an updated cloud reference released this week by the World Meteorological Organization. Meteorologist Kait Parker has the details. 
  
 At a Glance Several new cloud classifications have been added by the World Meteorological Organization. 
  
 The new classifications are the first in 30 years for the International Cloud Atlas. 
  
 Asperitas and murus are just two of the names you'll see among several new classifications added to an updated cloud reference released this week by the World Meteorological Organization (WMO) . 
  
 This update is the first in 30 years for the International Cloud Atlas , which the WMO calls "the global reference for observing and identifying clouds." 
  
 A new cloud species has been added to the atlas called volutus, more commonly known as a roll cloud by meteorologists. Cloud species are subdivisions of the 10 basic cloud "genera," the WMO says . 
  
 <img class="styles__noscript__2rw2y" src="https://s.w-x.co/roll-large.jpg" srcset="https://s.w-x.co/roll-large.jpg 400w, https://s.w-x.co/roll-large.jpg 800w" > A roll/volutus cloud in Sterling, Virginia, during September 2013. (National Weather Service Baltimore/Washington) 
  
 Roll/volutus clouds are a relatively rare, low-level, horizontal, tube-shaped cloud. Although they are associated with a thunderstorm (or occasionally a cold front), they are completely detached from the base of the cumulonimbus cloud. Volutus is a Latin term for rolled, which perfectly matches their appearance. 
  
 (MORE: How a Roll Cloud Forms ) 
  
 Five new supplementary features have also been added to the updated cloud atlas. Those new names include asperitas, cavum, cauda, fluctus, and murus, all of which are currently known as other more common names by sky watchers. 
  
 Asperitas, Latin for wave-like and roughness , has been added to the atlas thanks to the work of the Cloud Appreciation Society . 
  
 <img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/asperatus_oh-1.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/asperatus_oh-1.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/asperatus_oh-1.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > Asperitas Clouds Cincinnati, Ohio, on August 3, 2015. (Ron Steele) 
  
 “Asperitas was first identified with the help of citizen science, enabled by modern technology. When Cloud Appreciation Society members send us photographs of dramatic skies from around the world, it is possible to spot patterns. This is how the proposal for a new classification came about, and we are delighted the WMO has chosen to include it in their definitive reference work for cloud classification,” said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society. 
  
 (MORE: The Formation of Undulatus Asperatus ) 
  
 The other four new supplementary features now in the atlas also have more commonly known names among meteorologists. 
  
 Murus and cauda are a wall cloud and tail cloud, respectively. They are features of cumulonimbus clouds, which are associated with thunderstorms. Wall clouds are a lowering, rotating cloud base and sometimes the location where tornadoes can develop. A tail cloud extends horizontally away from the wall cloud and illustrates air feeding into the storm . 
  
 <img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/wall-tail-cloud.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/wall-tail-cloud.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/wall-tail-cloud.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > Wall Cloud with a Tail Cloud NOAA Photo Library, NOAA Central Library; OAR/ERL/National Severe Storms Laboratory (NSSL) 
  
 Hole-punch, or fallstreak, clouds have been given the supplementary feature name Cavum, while Fluctus has been added to describe Kelvin-Helmholtz wave clouds. 
  
 (MORE: Hole-Punch Clouds | Kelvin-Helmholtz Clouds ) 
  
 <img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/wave-clouds.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com//util/image/w/wave-clouds.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 400w, https://dsx.weather.com//util/image/w/wave-clouds.jpg?v=ap&w=980&h=551&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0 800w" > Kelvin-Helmholtz Wave Clouds Breckenridge, Colorado, in late October 2015. (Instagram/danielbannach) 
  
 Clouds that formed or grew from localized factors have also been added to the atlas. Among the five new "special clouds" is homogenitus, which is a contrail created by airplanes. 
  
 The International Cloud Atlas was first published in the 19th century and was last updated in 1987. This new 2017 version will primarily be accessible through the internet , but it could be published in print later. 
  
 “The International Cloud Atlas is the single most authoritative and comprehensive reference for identifying clouds. Its reputation is legendary among cloud enthusiasts and it serves as an essential training tool for professionals working in meteorological services, and in sectors such as aviation and shipping,” said WMO Secretary-General Petteri Taalas. 
  
 MORE ON WEATHER.COM: Mammatus Clouds ||||| The World Meteorological Organization (WMO) has released its new, long-awaited, digitized International Cloud Atlas – the global reference for observing and identifying clouds, which are an essential part of weather, the climate system and the water cycle. It was released for the World Meteorological Day on 23rd March. 
  
 The new Atlas combines 19th century traditions with 21st century technology. It contains hundreds of images submitted by meteorologists, photographers and cloud lovers from around the globe. 
  
 It includes new classifications, including volutus, a roll cloud; clouds from human activities such as the contrail, a vapour trail sometimes produced by airplanes; and asperitas, a dramatic undulated cloud which captured the public imagination. It also features meteorological phenomena like rainbows, halos, snow devils and hailstones. 
  
 “The International Cloud Atlas is the single most authoritative and comprehensive reference for identifying clouds. Its reputation is legendary among cloud enthusiasts and it serves as an essential training tool for professionals working in meteorological services, and in sectors such as aviation and shipping,” said WMO Secretary-General Petteri Taalas. 
  
 “Throughout the centuries, few natural phenomena have inspired as much scientific thought and artistic reflection as clouds,” said Mr Taalas. “More than two millennia ago, Aristotle studied clouds and wrote a treatise addressing their role in the hydrological cycle. And today, scientists understand that clouds play a vital role in the Earth’s energy balance, climate and weather,” said Mr Taalas in a message for World Meteorological Day on 23 March. 
  
 “If we want to forecast weather we have to understand clouds. If we want to model the climate system we have to understand clouds. And if we want to predict the availability of water resources, we have to understand clouds,” said Mr Taalas. 
  
 Understanding Clouds is the theme of this year’s World Meteorological Day, which celebrates the anniversary of the convention establishing WMO in 1950 and showcases the essential contribution of National Meteorological and Hydrological Services to the safety and wellbeing of society. 
  
 The themes chosen for World Meteorological Day reflect topical weather, climate or water-related issues. Understanding Clouds was chosen to coincide with the launch of the digital version of the International Cloud Atlas, after an exhaustive revision process and a public call for images from all over the world. 
  
 19th Century Traditions 
  
 The International Cloud Atlas was first published in the late 19th century. It contains a detailed manual of standards and numerous plates of photographs of clouds and certain other weather phenomena. It was last updated in 1987 – before the Internet era. For the first time, the 2017 edition will primarily be a web-based portal, allowing for much richer content and presentation. It may be published in hard copy at a later date. 
  
 “This is THE world reference for observing and classifying clouds and other weather phenomena. The Atlas contains pictures, definitions, and explanations that are accepted and used by all WMO’s 191 Member countries and territories,” said Bertrand Calpini, President of WMO’s Commission for Instruments and Methods of Observation (CIMO), which oversaw the revision process. 
  
 “This new edition brings together for the first time all types of measurements, including very high-tech surface-based, in situ and space observations and remote sensing, thus giving to the human observer a revolutionary tool to understand clouds,” said Mr Calpini. 
  
 “The International Cloud Atlas task team had to choose from thousands of images from meteorologists, cloud lovers and photographers around the world,” said Chi-ming Shun, Director of the Hong Kong Observatory, which is hosting the web portal. “We selected the best of the best. We feel honoured to be involved in such a visible product of WMO. We applaud WMO for updating the International Cloud Atlas which provides a unique platform for engaging the public in better understanding clouds, weather and climate.” 
  
 Classification of Clouds 
  
 The present international system of Latin-based cloud classification dates back to 1803, when amateur meteorologist Luke Howard wrote The Essay on the Modifications of Clouds. 
  
 There are ten basic cloud “genera,” which are defined according to where in the sky they form and their approximate appearance. The new International Cloud Atlas has made no additions to these 10 genera. 
  
 High-level clouds typically have a base above about 5 000 metres (16 500 feet); middle-level clouds have a base that is usually between 2 000 and 7 000 m (6 500 to 23 000 feet); and low-level clouds usually have their base at a maximum of 2 000 m (6 500 feet). 
  
 Most cloud names contain Latin prefixes and suffixes which, when combined, give an indication of the cloud’s character. These include: 
  
 Alto: mid-level (though Latin for high) 
  
 Cirrus/cirro: feathers, wispy 
  
 Cumulus/cumulo: heaped up/puffy 
  
 Nimbus/nimbo: rain-bearing 
  
 Stratus/strato: flat/layered and smooth 
  
 The 10 genera are subdivided into “species,” which describe shape and internal structure, and “varieties,” which describe the transparency and arrangement of the clouds. In total there are about 100 combinations. 
  
 The new International Cloud Atlas has added a new species: volutus or roll cloud (from the Latin volutus which means rolled), which occurs within the genera Altocumulus and Stratocumulus. It describes a long, typically low, horizontal tube shaped cloud mass that often appeals to roll about a horizontal axis. 
  
 Five new supplementary features have been added: asperitas, cavum, cauda (often known as tail cloud), fluctus (widely known as Kelvin-Helmholz wave) and murus (known as wall cloud). 
  
 Best known of these is asperitas (from the Latin meaning roughness), Photographs of the dramatic, wave-like cloud captured the popular imagination around the world. The Cloud Appreciation Society argued for a new classification to be used to describe clouds with this appearance. The Atlas includes the winning photograph from a Cloud Appreciations Society competition on Asperitas. 
  
  
  
 “Asperitas was first identified with the help of citizen science, enabled by modern technology. When Cloud Appreciation Society members send us photographs of dramatic skies from around the world, it is possible to spot patterns. This is how the proposal for a new classification came about, and we are delighted the WMO has chosen to include it in their definitive reference work for cloud classification,” said Gavin Pretor-Pinney, founder of the Cloud Appreciation Society. 
  
 A new accessory cloud, flumen, has been included. Commonly known as “beaver’s tail,” it is associated with a supercell severe convective storm. 
  
 The International Cloud Atlas also proposes five new “special clouds:” cataractagenitus, flammagenitus, homogenitus, silvagenitus and homomutatus. The suffix genitus indicates localized factors that led to cloud formation or growth, while mutatus is added when these caused the cloud to change from a different form. These special clouds are influenced by large waterfalls, localized heat from wildfires, saturation of air above forests and humans. Thus, a common example of homogenitus is contrails, sometimes seen after aircraft. 
  
 The World Meteorological Day ceremony will be webcast live to allow cloud enthusiasts around the world to have their first view of the new International Cloud Atlas and the new insight it provides into the beauty and power of nature. 
  
 Details of World Meteorological Day are available here 
  
 The message from WMO Secretary-General is available here 
  
 The International Cloud Atlas is available at https://cloudatlas.wmo.int 
  
 The new classifications are available here 
  
 The World Meteorological Organization is the United Nations System’s authoritative voice on Weather, Climate and Water 
  
 WMO website: public.wmo.int 
  
 For more information, please contact: 
  
 Clare Nullis, Press Officer, Communications and Public Affairs, Tel: +41 22 730 8478 or +41 79 709 13 97 (cell), e‑mail: cnullis@wmo.int. ||||| Only Meteor Type 
  
 Clouds Special Clouds and other Features Hydrometeors Lithometeors Photometeors Electrometeors Others 
  
 Clouds 
  
 Select Cloud Genus Cirrus(Ci) Cirrocumulus(Cc) Cirrostratus(Cs) Altocumulus(Ac) Altostratus(As) Nimbostratus(Ns) Stratocumulus(Sc) Stratus(St) Cumulus(Cu) Cumulonimbus(Cb) 
  
 Calvus Capillatus Castellanus Congestus Fibratus Floccus Fractus Humilis Lenticularis Mediocris Nebulosus Spissatus Stratiformis Uncinus Volutus 
  
 Duplicatus Intortus Lacunosus Opacus Perlucidus Radiatus Translucidus Undulatus Vertebratus 
  
 Arcus Asperitas Cauda Cavum Fluctus Flumen Incus Mamma Murus Pannus Pileus Praecipitatio Tuba Velum Virga 
  
 Altocumulus Altostratus Cataractagenitus Cirrocumulus Cumulonimbus Cumulus Flamma Homo Nimbostratus Silvagenitus Stratocumulus 
  
 Altocumulus Altostratus Cirrocumulus Cirrostratus Cirrus Cumulus Homomutatus Nimbostratus Stratocumulus Stratus 
  
 Special Clouds and other Features 
  
 Stratospheric Clouds : Polar Stratospheric Clouds (Nacreous Clouds) - Type I Stratospheric Clouds : Polar Stratospheric Clouds (Nacreous Clouds) - Type II Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Unknown Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type I (Veils) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IIa (Bands) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IIb (Bands) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IIIa (Billows) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IIIb (Billows) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IVa (Whirls) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IVb (Whirls) Mesospheric Clouds : Polar Mesospheric Clouds (Noctilucent Clouds) - Type IVc (Whirls) Mesospheric Clouds : Complex Structures - O Mesospheric Clouds : Complex Structures - S Mesospheric Clouds : Complex Structures - P Mesospheric Clouds : Complex Structures - V Aircraft condensation trails (Contrails) Asperitas Banner cloud Cirrus clouds formed from the spreading out of contrails Clouds formed above large waterfalls (e.g. Victoria or Niagara Falls) Clouds formed over forests Aircraft dissipation trails (Distrails or 'canal clouds') Fallstreak holes / Hole-punch clouds Fumulus (e.g. Cumulus formed above power stations) Horseshoe vortex Kelvin-Helmholtz waves Levanter (i.e. cloud that forms from the Rock of Gibralter) Pile d'assiettes (multi- layered lenticular clouds) Pyrocumulus (e.g. cumulus clouds formed above forest/wild fires, volcanoes) Roll cloud (e.g. the Morning Glory) Rotor cloud The Table Cloth (cloud formed over Table Mountain, South Africa) Anvil dome Anvil rollover / mushroom Back-sheared anvil Barber pole Bear's cage Beaver's Tail Clear slot Collar cloud Cumuliform anvil Feeder (inflow) bands Inflow stinger Knuckles Overshooting top Rain foot Rain-free base Supercell Tail cloud Turkey Tower Wall cloud Spouts - Funnel cloud Spouts - Tornado Spouts - Landspout Spouts - Waterspout Spouts - Gustnado 
  
 Meteors other than Clouds 
  
 Advection dew Advection fog Advection hoar frost Arctic sea smoke/frost smoke/steam fog Blowing snow Clear ice Deposit of fog droplets Dew proper Diamond dust Drifting snow Drizzle Fern frost/Window frost/Ice flowers Fog Frost flowers Glaze Hail Hard rime Hill fog/Upslope fog Hoar frost proper Ice fog Ice pellets Mist Needle ice/frost pillars/frost column Radiation fog Rain Sea fog Shallow fog/ground fog Small hail Snow Snow drift Snow grains Snow pellets Snow rollers Snowflakes/snow crystals Soft rime Spout Spray Supercooled drizzle Supercooled rain White dew 
  
 Blowing dust or sand Drift dust or sand Dust haze Dust storm or sandstorm Dust whirl or sand whirl (dust devil) Haze Smoke Wall of dust or sand 
  
 22-degree Halos 46-degree Halos Anthelion Anti-crepuscular rays Antiselene Bishop's ring Brocken spectre Circumhorizon Arcs Circumscribed halo Circumzenithal Arcs Cloud shadows Contrail shadows Corona: lunar corona Corona: solar corona Crepuscular rays Fata Morgana Fog bow Glory Green flash Halo: lunar halo Halo: solar halo Irrisation on clouds Light pillar Lowitz arcs Mirage Mirage: inferior Mirage: mock mirage Mirage: superior Novaya Zemlya effect Paranthelia Parantiselenae Paraselenae Parhelia Parhelic circle Rainbow Rainbow: Primary bow Rainbow: red Rainbow: reflected bows Rainbow: reflection bows Rainbow: secondary bow Rainbow: spray bow Rainbow: supernumerary bows Rainbow: twinned bow Scintillation Shimmer Subsun Sun/moon pillars Sundogs Supralateral arc Tangent Arcs Terrestrial light pillars Twilight colours Twilight colours: Alpengluhen Twilight colours: purple light Twilight colours: twilight arch Twilight rays Twilight shadows 
  
 Anvil crawler Anvil zits Blue jets Elves Polar aurora Red sprites Saint Elmo's fire Thunderstorm - Lightning Thunderstorm - Thunder 
  
 Climate Classification 
  
 Select Main Climate Equatorial (A) Arid (B) Warm Temperate (C) Snow (D) Polar (E) 
  
 Select Climate Precipitation Desert (W) Steppe (S) Fully Humid (f) Summer Dry (s) Winter Dry (w) Monsoonal (m) 
  
 Select Climate Temperature Hot Arid (h) Cold Arid (k) Hot Summer (a) Warm Summer (b) Cold Summer (c) Extremely Continental (d) Polar Frost (F) Polar Tundra (T) 
  
 CH Code 
  
 Select CH Code / 0 1 2 3 4 5 6 7 8 9 
  
 CM Code 
  
 Select CM Code / 0 1 2 3 4 5 6 7 8 9 
  
 CL Code 
  
 Select CL Code / 0 1 2 3 4 5 6 7 8 9 
  
  |||||
What is a summary?
– Look up in the sky: It's a bird, it's a plane, it's a … volutus, or is that an asperitas? If you're not sure what kind of cloud you're seeing above your head, consult the World Meteorological Organization's International Cloud Atlas, newly updated just in time for World Meteorological Day on Thursday. The Weather Channel reports that a bunch of new classifications have been added to the atlas (the first fully web-based version) for the first time in three decades, including the volutus "roll cloud" and aforementioned asperitas, as well as human-created cloud types like contrails (the condensation trails left in the wake of airplanes). There's even a new "accessory" cloud known as the flumen (aka "beaver's tail"), which sometimes follows along with a convective storm, a WMO press release notes. The science behind the atlas's cloud classifications, which Live Science calls "not for the faint of heart," is a sophisticated one. The 10 cornerstone clouds, referred to as "genera," are the ones you've likely heard of—stratus and cumulus, among others. Then the classification gets more granular with "species," which break down the genera clouds further based on shapes, and from there to "varieties," which indicate transparency and arrangement. The recent additions fall under the species category; there's also a new "supplementary features" section of "unusual parts"—such as the aforementioned asperitas, a wavy look to a cloud's underside—and five "special" clouds, including the contrail and clouds formed by waterfall mist. "Few natural phenomena" are as inspiring as clouds, WMO Secretary-General Petteri Taalas notes. (Shifting cloud patterns are worrisome.)
Artikel: Fokuserade kryp är samlingar av ofta uppdaterade webbkrypdata från smala (i motsats till breda eller breda) webbkryp, ofta inriktade på en enda domän eller underdomän. En volutus, eller rullmoln, fotograferad i Szprotawa, Polen. Denna typ av moln tillkom precis som ny art i 2017 års internationella molnatlas. En dramatiskt turbulent molnformation som kallas asperitas och det bisarrt cylindriska rullmolnet är bland de nyaste tilläggen till den internationella handboken för molnidentifiering. Meteorologiska världsorganisationen har släppt en ny digitaliserad version av sin "International Cloud Atlas", den globala referensboken för meteorologer och skyskådare. Det är den första uppdateringen för atlasen sedan 1987 och den första versionen att vara helt webbaserad. Utgivningen markerar också en röd-bokstavsdag för amatörentusiaster i Cloud Appreciation Society, som får tillfredsställelsen av att se det asperitasmoln som de upptäckt bli en officiell vetenskaplig kategori. "Det är en ny klassificering av moln, med ett kaotiskt, turbulent utseende, som föreslogs av Cloud Appreciation Society redan 2008, baserat på fotografier som skickats till oss från medlemmar runt om i världen," organisationen postade på sin blogg. "Det är ett klassiskt exempel på medborgarvetenskap, där observationer från allmänheten, som möjliggörs av tekniken för smartphones och Internet, har påverkat utvecklingen av denna mest officiella klassificeringssystem." Molnet atlas klassifikationssystem är inte för de svaga. Det finns 10 grundläggande "genera" av moln, varav de flesta namn skulle vara bekanta för skolbarn: cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, stratocumulus, stratus, cumulus och cumulonimbus. Inom varje släkte finns arter, som beskriver den inre strukturen hos molnens form. Ett lenticularismoln är till exempel en tillplattad pannkaksform som ser lite ut som ett gigantiskt UFO. Varje typ av moln kan bara ha en art, men samma arttyper förekommer i flera olika släkten av moln. En bild av en fotometeor gloria som ingår i den nya internationella molnatlasen. Halos orsakas av att ljuset reflekterar eller bryter av små iskristaller som är upphängda i atmosfären, enligt Atlas. Tillgodoräknande: WMO International Cloud Atlas/Claudia Hinz, DMD Därefter omfattar klassificeringssystemet varianter av moln, som beskriver molnens transparens och arrangemang. Ett enda moln kan ha flera varianter, förutom när det gäller opacus (ogenomskinliga) molnsorter och translucidus (genomskinliga) sorter, som utesluter varandra: Den ena släpper inte igenom någon sol, och den andra gör det. [Se foton av olika molntyper] Således kan en standardmolnidentifiering se ut ungefär som "altocumulus stratiformis translucidus perlucidus undulates" – ett altocumulusmoln som är arrangerat i ett tunt ark (stratiformis) som är genomskinligt mot solljus, har små luckor som gör att blå himmel kan visa igenom (perlucidus) och som har vågiga drag (okulerade). Molnatlasuppdateringen ändrar inte någon av de grundläggande klassificeringarna för moln, men den lägger till flera nya vändningar. Rullmolnet, som kallas volutus, definieras som en ny molnart. Dessa horisontella, cylindriska moln bildar där fallande kall luft trycker varm, fuktig luft uppåt. Under rätt vindförhållanden kondenserar den atmosfäriska turbulensen till ett rörformigt moln som verkar rulla över himlen. Ett böljande asperitasmoln, fotograferat på Shorewell Park i Tasmanien, Australien, klockan 07.48 lokal tid den 20 februari 2004. Kredit: WMO International Cloud Atlas/ © Gary McArthur Atlantas lägger också till fem nya "kompletterande funktioner" till sitt klassificeringssystem. Kompletterande egenskaper är ovanliga delar av, eller fästen vid, moln. De våglika vågformiga vågorna på molnens undersidor, dubbade till "asperitas", hör till dessa nya drag. En annan är "cavum", känd kollokvialt som ett hålpunchmoln eftersom molnet har ett stort cirkulärt gap genom vilket himlen kan ses. En "cauda" är ett horisontellt inslag som sträcker sig som en svans från ett moln. "Fluctus" funktioner är vågformationer som ser ut som något en tecknad surfare skulle rida; de är allmänt kända som Kelvin-Helmholtz vågor och orsakas av vind skjuvning. Slutligen är "murus" drag, eller väggmoln, bekanta för någon stormjagare för deras roll i tornados bildning. De andra huvudändringarna i atlasen är tillägget av ett nytt accessoriskt moln, eller ett moln som åtföljer ett annat, större moln, och etableringen av fem nya speciella moln, som beskriver ovanliga molnbildningsförhållanden. Den nya accessoarmolntypen kallas "flumen" och beskriver ett lågt moln som förknippas med svåra supercellstormar. De fem nya speciella molnen är: kataraktagenitus, som beskriver moln som utvecklas ur stänket av stora vattenfall; flammagenitus, som beskriver moln som bildas under påverkan av löpeldar; homogenitus, som beskriver moln som bildas av mänskliga aktiviteter, såsom flygplanskontrailer; silvagenitus, som beskriver moln som bildas under påverkan av fukt från respiratoriska träd; och homomutatus, som beskriver moln som ursprungligen gjorts av människor som gradvis förvandlas till mer naturliga former, som en contrail som så småningom sprids i vinden. Molnet atlas finns tillgängligt online och kommer att vara officiellt avtäckt idag (23 mars) för World Meteorological Day. Originalartikel om Levande vetenskap. ## 00:50 Nya molntyper Tillagd Asperitas och murus är bara två av de namn du kommer att se bland flera nya klassificeringar som lagts till en uppdaterad molnreferens som släpptes denna vecka av World Meteorological Organization. Meteorolog Kait Parker har detaljerna. Vid en Glance Flera nya molnklassificeringar har tillkommit av World Meteorological Organization. De nya klassificeringarna är de första på 30 år för International Cloud Atlas. Asperitas och murus är bara två av de namn du kommer att se bland flera nya klassificeringar som lagts till en uppdaterad molnreferens som släpptes denna vecka av World Meteorological Organization (WMO) . Denna uppdatering är den första på 30 år för International Cloud Atlas , som WMO kallar "den globala referensen för att observera och identifiera moln." En ny molnart har tillkommit i atlasen som kallas volutus, mer allmänt känd som ett rullmoln av meteorologer. Molnarter är underavdelningar till de 10 grundläggande molnen "genera", säger WMO . <img class="styles__noscript__2rw2y" src="https://s.w-x.co/roll-large.jpg" srcset="https://s.w-x.co/roll-large.jpg 400w, https://s.w-x.co/roll-large.jpg 800w" > Ett roll/volutusmoln i Sterling, Virginia, under september 2013. (National Weather Service Baltimore/Washington) Rull-/volutusmoln är ett relativt sällsynt, lågnivå, horisontellt, rörformat moln. Även om de är förknippade med ett åskväder (eller ibland en kallfront), är de helt loss från basen av cumulonimbus moln. Volutus är en latinsk term för rullad, som perfekt matchar deras utseende. (MORE: How a Roll Cloud Forms) Fem nya tilläggsfunktioner har också lagts till den uppdaterade molnatlas. Dessa nya namn inkluderar asperitas, cavum, cauda, fluctus och murus, som alla för närvarande är kända som andra vanligare namn av himmelsväktare. Asperitas, latin för våglik och grovhet, har lagts till atlasen tack vare arbetet i Cloud Appreciation Society. <img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/asperatus_oh-1.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com/util/image/w/asperatus_oh-1.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-4871-e17d87b8b6a0 400w, https://dsx.weather.com/util/image/w/asperatus_oh-1.jpg=980&w=551api=3,7db3-898b8b8b8b8a. (Ron Steele) ”Asperitas identifierades först med hjälp av medborgarvetenskap, som möjliggörs av modern teknik. När medlemmar av Cloud Appreciation Society skickar oss bilder av dramatisk himmel från hela världen, är det möjligt att upptäcka mönster. Det är så förslaget till en ny klassificering kom till, och vi är glada att WMO har valt att inkludera det i deras definitiva referensarbete för molnklassificering, säger Gavin Pretor-Pinney, grundare av Cloud Appreciation Society. (MORE: The Formation of Undulatus Asperatus) De andra fyra nya kompletterande funktioner nu i atlasen har också mer allmänt kända namn bland meteorologer. Murus och cauda är ett väggmoln respektive svansmoln. De är drag hos cumulonimbusmoln, som är förknippade med åskväder. Väggmoln är en sjunkande, roterande molnbas och ibland den plats där tornador kan utvecklas. Ett svansmoln sträcker sig horisontellt bort från väggmolnet och illustrerar luft som matar in sig i stormen. <img class="styles__noscript__2rw2y" src="https://dsx.weather.com/util/image/w/wall-tail-cloud.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b6a0" srcset="https://dsx.weather.com/util/image/w/wall-tail-cloud.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-971-e17d87b8b6b6a0 400w, https://dsx.weather/util/w/wall-tail-moln.jpg=7db&api=914-47b5db9f14-47-47-47b2b2b2bx8bx8bx8bx8a4Ax8bx8a4Ax8a8Ax8bx8bx8bx8bx8bx8bx8bx8bx8bx8bx8bx8bx8bx8bx8b (MORE: Hole-Punch Clouds ^ Kelvin-Helmholtz Clouds ) <img class="styles__noscript__2rw2y" src="https://dsx.weather.com/util/image/w/wave-clouds.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b6a0" srcset="https://dsx.weather.com/util/image/w/wave-clouds.jpg?v=at&w=485&h=273&api=7db9fe61-74b5-47b5-98d87b8b6a0 400w, https://dsxx.w/image/w/w/wp=885&8&8&8hp&8hp=8h8hhow. (Instagram/danielbannach) Moln som bildats eller vuxit fram ur lokaliserade faktorer har också tillkommit atlasen. Bland de fem nya "specialmolnen" finns homogenitus, som är en contrail skapad av flygplan. Internationella molnatlasen publicerades första gången på 1800-talet och uppdaterades senast 1987. Denna nya 2017-version kommer i första hand att vara tillgänglig via internet , men den skulle kunna publiceras i tryck senare. ”International Cloud Atlas är den enskilt mest auktoritativa och omfattande referensen för att identifiera moln. Dess rykte är legendariskt bland molnentusiaster och det fungerar som ett viktigt utbildningsverktyg för yrkesverksamma inom meteorologiska tjänster, och inom sektorer som luftfart och sjöfart, säger WMO Generalsekreterare Petteri Taalas. MER PÅ VÄTSKA.COM: Mammatus Moln .....................Världens meteorologiska organisation (WMO) har släppt sin nya, efterlängtade, digitaliserade internationella molnatlas – den globala referensen för att observera och identifiera moln, som är en väsentlig del av vädret, klimatsystemet och vattencykeln. Den släpptes till Meteorologiska världsdagen den 23 mars. Den nya Atlas kombinerar 1800-talstraditioner med 2000-talsteknologi. Den innehåller hundratals bilder som lämnats in av meteorologer, fotografer och molnälskare från hela världen. Den innehåller nya klassificeringar, inklusive volutus, ett rullmoln; moln från mänskliga aktiviteter som contrailen, ett ångspår som ibland produceras av flygplan; och asperitas, ett dramatiskt undulat moln som fångade allmänhetens fantasi. Den har också meteorologiska fenomen som regnbågar, glorior, snödjävlar och hagelstenar. ”International Cloud Atlas är den enskilt mest auktoritativa och omfattande referensen för att identifiera moln. Dess rykte är legendariskt bland molnentusiaster och det fungerar som ett viktigt utbildningsverktyg för yrkesverksamma inom meteorologiska tjänster, och inom sektorer som luftfart och sjöfart, säger WMO Generalsekreterare Petteri Taalas. – Under århundradenas lopp har få naturfenomen inspirerat till så mycket vetenskapligt tänkande och konstnärlig reflektion som moln, säger Taalas. – För mer än två årtusenden sedan studerade Aristoteles moln och skrev en avhandling om deras roll i den hydrologiska cykeln. Och idag, forskare förstår att moln spelar en viktig roll för jordens energibalans, klimat och väder, säger Mr Taalas i ett meddelande för World Meteorological Day den 23 mars. – Om vi vill förutsäga vädret måste vi förstå molnen. Om vi vill modellera klimatsystemet måste vi förstå molnen. Och om vi vill förutsäga tillgången på vattenresurser, måste vi förstå moln, sade Taalas. Understanding Clouds är temat för årets Meteorologiska dag, som firar årsdagen av konventionen om inrättande av WMO 1950 och visar det viktiga bidraget från nationella meteorologiska och hydrologiska tjänster till samhällets säkerhet och välbefinnande. De teman som valts ut för världsmeteorologiska dagen återspeglar aktuella väder-, klimat- eller vattenrelaterade frågor. Understanding Clouds valdes för att sammanfalla med lanseringen av den digitala versionen av International Cloud Atlas, efter en uttömmande revisionsprocess och en offentlig uppmaning till bilder från hela världen. 1800-talets traditioner Den internationella molnatlasen publicerades första gången i slutet av 1800-talet. Den innehåller en detaljerad handbok av standarder och många plattor med fotografier av moln och vissa andra väderfenomen. Den uppdaterades senast 1987 – före Interneteran. För första gången kommer 2017 års upplaga i första hand att vara en webbaserad portal, vilket möjliggör mycket rikare innehåll och presentation. Den får ges ut i pappersversion vid ett senare tillfälle. – Det här är världsreferensen för att observera och klassificera moln och andra väderfenomen. Atlas innehåller bilder, definitioner och förklaringar som accepteras och används av alla WMO:s 191 medlemsländer och territorier, säger Bertrand Calpini, ordförande för WMO:s kommission för instrument och metoder för observation (CIMO), som övervakade revisionsprocessen. “Denna nya utgåva samlar för första gången alla typer av mätningar, inklusive mycket högteknologiska ytbaserade, in situ-och rymdobservationer och fjärranalys, vilket ger den mänskliga observatören ett revolutionerande verktyg för att förstå moln,” sade Calpini. “International Cloud Atlas uppgiftsteam hade att välja mellan tusentals bilder från meteorologer, molnälskare och fotografer runt om i världen,” sade Chi-ming Shun, direktör för Hong Kong Observatory, som är värd för webbportalen. – Vi valde ut de bästa av de bästa. Vi känner oss hedrade över att vara involverade i en sådan synlig produkt av WMO. Vi applåderar WMO för att uppdatera International Cloud Atlas som ger en unik plattform för att engagera allmänheten i bättre förståelse moln, väder och klimat.” Klassificering av moln Det nuvarande internationella systemet av latinbaserad molnklassificering går tillbaka till 1803, när amatörmeteorologen Luke Howard skrev The Essay on the Modifications of Clouds. Det finns tio grundläggande moln "genera", som definieras efter var på himlen de bildas och deras ungefärliga utseende. Den nya International Cloud Atlas har inte gjort några tillägg till dessa 10 släkten. Högnivåmoln har typiskt en bas över cirka 5 000 meter (16 500 fot); medelnivåmoln har en bas som vanligen ligger mellan 2 000 och 7 000 m (6 500 till 23 000 fot); och lågnivåmoln har vanligen sin bas på maximalt 2 000 m (6 500 fot). De flesta molnnamn innehåller latinska prefix och suffix som när de kombineras ger en indikation på molnets tecken. Dessa inkluderar: Alto: medelnivå (om än latin för hög) Cirrus/cirro: fjädrar, wispy Cumulus/cumulo: hopad/puffig Nimbus/nimbo: regnbärande Stratus/strato: platt/skiktad och slät De 10 släktena är uppdelade i “arter”, som beskriver form och inre struktur, och “variationer”, som beskriver transparens och arrangemang av molnen. Totalt finns cirka 100 kombinationer. Den nya Internationella molnatlasen har lagt till en ny art: volutus eller rullmoln (från latinets volutus som betyder rullad), som förekommer inom släktena Altocumulus och Stratocumulus. Den beskriver en lång, typiskt låg, horisontell rörformad molnmassa som ofta tilltalar att rulla runt en horisontell axel. Fem nya tilläggsfunktioner har tillkommit: asperitas, cavum, cauda (ofta känd som svansmoln), faktus (bredbekant som Kelvin-Helmholz våg) och murus (känd som väggmoln). Mest känd av dessa är asperitas (från latinets betydelse grovhet), Fotografier av det dramatiska, vågliknande molnet fångade den populära fantasin runt om i världen. The Cloud Appreciation Society argumenterade för att en ny klassificering skulle användas för att beskriva moln med detta utseende. Atlas innehåller det vinnande fotografiet från en tävling i Cloud Appreciations Society på Asperitas. – Asperitas identifierades först med hjälp av medborgarvetenskap, vilket möjliggörs av modern teknik. När medlemmar av Cloud Appreciation Society skickar oss bilder av dramatisk himmel från hela världen, är det möjligt att upptäcka mönster. Det är så förslaget till en ny klassificering kom till, och vi är glada att WMO har valt att inkludera det i deras definitiva referensarbete för molnklassificering, säger Gavin Pretor-Pinney, grundare av Cloud Appreciation Society. Ett nytt accessoarmoln, flumen, har inkluderats. Vanligen känd som "bäverstjärt", är den förknippad med en supercell svår konvektiv storm. International Cloud Atlas föreslår också fem nya ”speciella moln:” kataraktagenitus, flammagenitus, homogenitus, silvagenitus och homomutatus. Suffixet genitus anger lokaliserade faktorer som ledde till molnbildning eller tillväxt, medan mutagenus läggs till när dessa fick molnet att förändras från en annan form. Dessa speciella moln påverkas av stora vattenfall, lokal värme från skogsbränder, mättnad av luft ovanför skogar och människor. Ett vanligt exempel på homogenitus är alltså contrails, ibland sett efter flygplan. Världsmeteorologiska dagen kommer att vara webbsändning live för att göra det möjligt för molnentusiaster runt om i världen att få sin första syn på den nya internationella molnatlasen och den nya insikten om naturens skönhet och kraft. Mer information om världsmeteorologiska dagen finns här WMO:s generalsekreterares meddelande The International Cloud Atlas finns på https://cloudatlas.wmo.int De nya klassificeringarna finns här. Världsmeteorologiska organisationen är FN-systemets auktoritativa röst på WMO:s webbplats: public.wmo.int För mer information, kontakta: Clare Nullis, pressansvarig, kommunikations- och public affairs, tfn: +41 22 730 8478 eller +41 79 709 13 97 (cell), e-post: cnullis@wmo.int. Det finns en del av det här systemet, och det finns en del av det här. Victoria eller Niagarafallen) Moln bildas över skogar Flygplansavledningsleder (Distrails eller 'kanalmoln') Fallgatahål / Hålpunchmoln Fumulus (t.ex. Cumulus bildades ovanför kraftstationer) Horseshoe virvel Kelvin-Helmholtz vågor Levanter (d.v.s. moln som bildas från Gibralterklippan) Pile d'assiettes (flerskiktade lentikulära moln) Pyrocumulus (t.ex. cumulusmoln som bildas ovanför skogs-/vildbränder, vulkaner) Rullmoln (t.ex. 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Article: Focused Bugs are collections of often updated Web Bug Data from narrow (as opposed to wide or wide) web bugs, often focused on a single domain or subdomain. A volutus, or roll cloud, photographed in Szprotawa, Poland. This type of cloud was added just like new species in the 2017 International Cloud Atlas. A dramatically turbulent cloud formation called asperitas and the bizarre cylindrical roller cloud is among the newest additions to the international cloud identification manual. The World Meteorological Organization has released a new digitized version of its "International Cloud Atlas", the global reference book for meteorologists and skysight-watchers. It is the first update for the atlas since 1987 and the first version to be completely web-based. The release also marks a red-letter day for amateur enthusiasts of the Cloud Appreciation Society, who gain the satisfaction of seeing the asperitas cloud they discovered become an official scientific category. "It's a new classification of clouds, with a chaotic, turbulent appearance, as proposed by the Cloud Appreciation Society back in 2008, based on photographs sent to us from members around the world," the organization posted on its blog. "It is a classic example of civic science, where observations from the public, enabled by the technology of smartphones and the Internet, have influenced the development of this most official classification system." The cloud atlas classification system is not for the weak. There are 10 basic "genera" of clouds, most of which names would be familiar to schoolchildren: cirrus, cirrocumulus, cirrostratus, altocomulus, altocomulus, nimbostratus, stratocumulus, stratus, cumulus and cumuloniimbus. Within each genus are species, describing the inner structure of the shape of the clouds. For example, a lenticularis cloud is a flattened pancake shape that looks a bit like a giant UFO. Each type of cloud can have only one species, but the same species types occur in several different genera of clouds. A picture of a photometeor halo that is part of the new international cloud Atlas. Halos is caused by light reflecting or breaking off small ice crystals suspended in the atmosphere, according to Atlas. Crediting: WMO International Cloud Atlas/Claudia Hinz, DMD Subsequently, the classification system includes variants of clouds, describing the cloud transparency and arrangements. A single cloud may have several variants, except in the case of opacus (untransparent) cloud varieties and translucidus (translucent) varieties, which are mutually exclusive: one does not let through any sun, and the other does. [See photos of different cloud types] Thus a standard cloud identification may look much like "altocumulus stratiformis translucidus perlucidus undulates" – an altocumulus cloud arranged in a thin sheet (stratiformis) that is transparent against sunlight, has small gaps that allow blue skies to show through (perlucidus) and that has wavy features (unculated). The Cloud Atlas update does not change any of the basic classifications for clouds, but it adds several new turns. The roll cloud, called volutus, is defined as a new cloud species. These horizontal, cylindrical clouds form where falling cold air presses hot, moist air upwards. Under the right wind conditions, the atmospheric turbulence condenses into a tubular cloud that appears to roll across the sky. An undulating asperitas cloud, photographed at Shorewell Park in Tasmania, Australia, at 7:48 a.m. local time on February 20, 2004. Credit: WMO International Cloud Atlas/ © Gary McArthur Atlantas also adds five new "complementary features" to its classification system. Supplementary properties are unusual parts of, or attachments to, clouds. The wave-like wave-shaped waves on the undersides of the clouds, dubbed "asperitas", are among these new features. Another is "cavum", known colloquially as a hole punch cloud because the cloud has a large circular gap through which the sky can be seen. A "cauda" is a horizontal element extending like a tail from a cloud. "Fluctus" features are wave formations that look like something a cartoon surfer would ride; they are commonly known as Kelvin-Helmholtz waves and are caused by wind shear. Finally, "murus" features, or wall clouds, are familiar to any storm destroyer for their role in tornado formation. The other main changes in the atlas are the addition of a new accessory cloud, or a cloud accompanying another, larger cloud, and the establishment of five new special clouds, describing unusual cloud formation conditions. The new accessory cloud type is called "flumen" and describes a low cloud associated with severe supercell storms. The five new special clouds are: catarachtagenitus, which describes clouds developing from the splash of large waterfalls; flamegenitus, which describes clouds formed under the influence of wildfires; homogenitus, which describes clouds formed by human activities, such as aircraft contrails; silvagenitus, which describes clouds formed under the influence of moisture from respiratory trees; and homomutatus, which describes clouds originally made by people who are gradually transformed into more natural forms, as a contrail eventually spread in the wind. Cloud atlas is available online and will be officially unveiled today (March 23) for World Meteorological Day. Original article on Living Science. # 00:50 New cloud types Added Asperitas and murus are just two of the names you will see among several new classifications added to an updated cloud reference released this week by the World Meteorological Organization. Meteorologist Kait Parker has the details. At a Glance Several new cloud classifications have been added by the World Meteorological Organization. The new classifications are the first in 30 years for the International Cloud Atlas. Asperitas and murus are just two of the names you will see among several new classifications added to an updated cloud reference released this week by the World Meteorological Organization (WMO). This update is the first in 30 years for the International Cloud Atlas , which WMO calls "the global reference for observing and identifying clouds." A new cloud species has been added to the atlas called volutus, more commonly known as a roll cloud of meteorologists. Cloud species are subdivisions of the 10 basic clouds "generate", WMO says. <img class="styles__noscript__2rw2y" src="https://s.w-x.co/roll-large.jpg" srcset="https://s.w-x.co/roll-large.jpg 400w, https://s.w-x.co/roll-large.jpg 800w" > A role/volutus cloud in Sterling, Virginia, during September 2013. (National Weather Service Baltimore/Washington) Roll/volutus cloud is a relatively rare, low-level, horizontal, tubular cloud. Although associated with a thunderstorm (or sometimes a cold front), they are completely detached from the base of cumulonimbi's cloud. Volutus is a Latin term for rolled, which perfectly matches their appearance. (MORE: How a Roll Cloud Forms) Five new additional features have also been added to the updated cloud Atlas. These new names include asperitas, cavum, cauda, fluctus, and murus, all of which are currently known as other more common names of sky guardians. Asperitas, Latin for wavelike and roughness, has been added to the atlas thanks to the work of the Cloud Appreciation Society. <img class="styles__noscript__2rw2y" src="https://dsx.weather.com//util/image/w/asperatus_oh-1.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b8b6a0" srcset="https://dsx.weather.com/util/image/w/asperatus_oh-1.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-487-e17d87b8b6a0 400w, https://dsx.weather.com/image/w/asperatus_1hpg=9551-7414-47b5-4871-e17b5-487-e17d8b8b8b8b8b8b8b8b (Ron Steele) ‘Asperitas was first identified using civic science, which is enabled by modern technology. When members of the Cloud Appreciation Society send us images of dramatic sky from around the world, it is possible to detect patterns. That's how the proposal for a new classification came into being, and we're happy that WMO has chosen to include it in their definitive reference work for cloud classification," says Gavin Pretor-Pinney, founder of Cloud Appreciation Society. (MORE: The Formation of Undulatus Asperatus) The other four new complementary functions now in the atlas also have more commonly known names among meteorologists. Murus and cauda are a wall cloud and tail cloud respectively. They are features of cumulonimbus clouds, associated with thunderstorms. Wall clouds are a sinking, rotating cloud base and sometimes the place where tornadoes can develop. A tail cloud extends horizontally away from the wall cloud and illustrates air feeding into the storm. <img clasx.weather.com/util/image/w/wall-tail-cloud.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b6a0" srcset="https://dsx.weather.com/util/image/w/wall-tail-cloud.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-971-ed87b8b6b6a0 400w, https://dsx.weather/w/wall-tail-cloud-cloud.jdb&api=7db=7db9fe61-7414-47b5-771-ed87b6b6b6b6a0 (MORE: Hole-Punch Clouds  Kelvin-Helmholtz Clouds ) <img class="styles__noscript__2rw2y" src="https://dsx.weather.com/util/image/w/wave-clouds.jpg?v=at&w=485&h=273&api=7db9fe61-7414-47b5-9871-e17d87b6a0" srcset="https://dsx.weather.com/util/image/w/wave-clouds.jpg?v=at&w=485&h=273&api=7db9fe61-74b5-47b5-98d87b8b8b6a0 400w, https://dsxx.w/wp?v=8&8h8h8h8h8h8h8h8h8h (Instagram/danielbannach) Clouds formed or emerged from localized factors have also been added to the atlas. Among the five new "special clouds" are homogenousitus, which is a contrail created by aircraft. The International Cloud Atlas was first published in the 19th century and last updated in 1987. This new 2017 version will primarily be available via the internet, but it could be published in print later. “International Cloud Atlas is the single most authoritative and comprehensive reference for identifying clouds. Its reputation is legendary among cloud enthusiasts and it serves as an important training tool for professionals in meteorological services, and in sectors such as aviation and shipping," says WMO Secretary General Petteri Taalas. MORE ON WATER.COM: Mammatus Cloud ....................The World Meteorological Organization (WMO) has released its new, long-awaited, digitized international cloud Atlas – the global reference to observe and identify clouds, which are an essential part of the weather, climate system and water cycle. It was released to Meteorological World Day on March 23. The new Atlas combines 19th-century traditions with 21st-century technology. It contains hundreds of images submitted by meteorologists, photographers, and cloud lovers from around the world. It contains new classifications, including volutus, a roll cloud; clouds from human activities such as the contrail, a steam track sometimes produced by aircraft; and asperitas, a dramatic undulate cloud that captured public imagination. It also has meteorological phenomena such as rainbows, halos, snow devils and hailstones. “International Cloud Atlas is the single most authoritative and comprehensive reference for identifying clouds. Its reputation is legendary among cloud enthusiasts and it serves as an important training tool for professionals in meteorological services, and in sectors such as aviation and shipping," says WMO Secretary General Petteri Taalas. “Over the centuries, few natural phenomena have inspired as much scientific thinking and artistic reflection as clouds,” says Taalas. “More than two millennia ago Aristotle studied the clouds and wrote a thesis about their role in the hydrological cycle. And today, scientists understand that clouds play an important role in the earth's energy balance, climate and weather," says Mr. Taalas in a message for World Meteorological Day on March 23. “If we want to predict the weather, we need to understand the clouds. If we want to model the climate system, we need to understand the clouds. And if we want to predict the availability of water resources, we need to understand clouds," said Taalas. Understanding Clouds is the theme of this year's Meteorological Day, which celebrates the anniversary of the Convention establishing the WMO in 1950 and shows the important contribution of national meteorological and hydrological services to the safety and well-being of society. The themes selected for World Meteorological Day reflect current weather, climate or water-related issues. Understanding Clouds was chosen to coincide with the release of the digital version of the International Cloud Atlas, following an exhaustive audit process and a public call for images from around the world. 19th century traditions The International Cloud Atlas was first published in the late 19th century. It contains a detailed manual of standards and many plates with photographs of clouds and some other weather phenomena. It was last updated in 1987 – before the Internet era. For the first time, the 2017 edition will primarily be a web-based portal, enabling much richer content and presentation. It may be published in paper version at a later date. “This is the world reference for observing and classifying clouds and other weather phenomena. Atlas contains images, definitions and explanations that are accepted and used by all the 191 WMO member countries and territories, says Bertrand Calpini, Chairman of the WMO Commission on Instruments and Methods of Observation (CIMO), who oversaw the audit process. “This new release collects for the first time all kinds of measurements, including highly high-tech surface-based, in situ and space observations and remote sensing, giving the human observer a revolutionary tool to understand clouds,” said Calpini. “The international Cloud Atlas task team had to choose between thousands of images from meteorologists, cloud lovers and photographers around the world,” said Chi-ming Shun, director of the Hong Kong Observatory, who hosts the web portal. “We selected the best of the best. We feel honored to be involved in such a visible product by WMO. We applaud the WMO to update the International Cloud Atlas that provides a unique platform to engage the public in better understanding cloud, weather and climate.” Cloud Classification The current international system of Latin-based cloud classification dates back to 1803, when amateur meteorologist Luke Howard wrote The Essay on the Modifications of Clouds. There are ten basic clouds "genera", defined by where in the sky they are formed and their approximate appearance. The new International Cloud Atlas has made no additions to these 10 genera. High-level clouds typically have a base over about 5,000 metres (16,500 feet); medium-level clouds have a base usually located between 2,000 and 7,000 m (6,500 to 23,000 feet); and low-level clouds usually have their base of a maximum of 2,000 m (6,500 feet). Most cloud names contain Latin prefixes and suffixes that when combined give an indication of the cloud's characters. These include: Alto: mean level (albeit Latin too high) Cirrus/cirro: feathers, wispy Cumulus/cumulo: piled up/puffy Nimbus/nimbo: rain-bearing Stratus/strato: flat/layered and smooth The 10 genera are divided into “species”, describing form and inner structure, and “variations”, describing transparency and arrangement of the clouds. A total of about 100 combinations are available. The new International Cloud Atlas has added a new species: volutus or roll clouds (from Latin volutus meaning rolled), which occur within the genera Altocumulus and Stratocumulus. It describes a long, typically low, horizontal tubular cloud mass that often appeals to rolling around a horizontal axis. Five new additional features have been added: asperitas, cavum, cauda (often known as tail clouds), phyctus (widely known as Kelvin-Helmholz wave) and murus (known as wall clouds). Best known of these are asperitas (from Latin meaning roughness), Photographs of the dramatic, wave-like cloud captured the popular imagination around the world. The Cloud Appreciation Society argued that a new classification would be used to describe clouds with this appearance. Atlas features the winning photograph from a contest in the Cloud Appreciations Society at Asperitas. “Asperitas was first identified using civic science, which is enabled by modern technology. When members of the Cloud Appreciation Society send us images of dramatic sky from around the world, it is possible to detect patterns. That's how the proposal for a new classification came into being, and we're happy that WMO has chosen to include it in their definitive reference work for cloud classification," says Gavin Pretor-Pinney, founder of Cloud Appreciation Society. A new accessory cloud, the flu, has been included. Commonly known as "beaver tail", it is associated with a supercell severe convective storm. The International Cloud Atlas also proposes five new “special clouds:” cataract tagenitus, flamegenitus, homogenitus, silvagenitus and homomutatus. The suffix genitus indicates localized factors that led to cloud formation or growth, while mutagenesis is added when these caused the cloud to change from another form. These special clouds are affected by large waterfalls, local heat from forest fires, saturation of air above forests and people. Thus, a common example of homogeneity is contrails, sometimes looked after aircraft. World Meteorological Day will be live webcasting to enable cloud enthusiasts around the world to get their first view of the new international cloud Atlas and the new insight into the beauty and power of nature. For more information on the World Meteorological Day, see the WMO Secretary General’s message The International Cloud Atlas at https://cloudatlas.wmo.int The new classifications can be found here. The UN system’s authoritative voice is on the WMO website: public.wmo.int For more information, please contact: Clare Nullis, Press Officer, Communications and Public Affairs, tel: +41 22 730 8478 or +41 79 709 13 97 (cell), e-mail: cnullis@wmo.int. There's a part of this system, and there's a part of this. 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Det är en fågel, ett plan, en volutus eller en asperitas? Om du inte är säker på vilken typ av moln du ser ovanför ditt huvud, konsultera Meteorologiska Världsorganisationen International Cloud Atlas, nyligen uppdaterad lagom till Meteorologiska Världsdagen på torsdag. Väderkanalen rapporterar att ett gäng nya klassificeringar har lagts till atlasen (den första helt webbaserade versionen) för första gången på tre decennier, bland annat volutus "rullmolnet" och tidigare nämnda asperitas, samt människoskapade molntyper som contrails (kondensationsspåren kvar i kölvattnet av flygplan). Det finns även ett nytt "accessory" moln som kallas flumen (aka "bäverstjärt"), som ibland följer tillsammans med en konvektiv storm, en WMO pressmeddelande anteckningar. Vetenskapen bakom atlasens molnklassificeringar, som Live Science kallar "inte för de svagas hjärta", är en sofistikerad sådan. De 10 hörnstensmolnen, som kallas "genera", är de som du troligen har hört talas om – bland annat Stratus och cumulus. Därefter blir klassificeringen mer granulär med "arter", som bryter ner släktesmolnen ytterligare baserat på former, och därifrån till "sorter", som indikerar transparens och arrangemang. De senaste tilläggen faller under artkategorin; det finns också en ny "kompletterande funktioner" sektion av "ovanliga delar" – såsom ovan nämnda asperitas, en vågig blick på ett molns undersida – och fem "special" moln, inklusive de contrail och moln som bildas av vattenfall dimma. "Få naturfenomen" är lika inspirerande som moln, konstaterar WMO:s generalsekreterare Petteri Taalas. (Skiftande molnmönster är oroande.)
It's a bird, a plane, a volutus or an asperitas? If you are not sure what type of cloud you see above your head, consult the World Meteorological Organization International Cloud Atlas, recently updated just in time for Meteorological World Day on Thursday. The weather channel reports that a bunch of new classifications have been added to the atlas (the first fully web-based version) for the first time in three decades, including the volutus "roll cloud" and previously mentioned asperitas, as well as human-created cloud types such as contrails (the condensation tracks left in the wake of aircraft). There is also a new "accessory" cloud called flumen (aka "beaver tail"), which sometimes follows along with a convective storm, a WMO press release notes. The science behind the atlas' cloud classifications, which Live Science calls "not the heart of the weak", is a sophisticated one. The 10 cornerstone clouds, called "genera", are those you have probably heard of – including Stratus and cumulus. Subsequently, the classification becomes more granular with "species", breaking down the genus clouds further based on shapes, and from there to "sorts", indicating transparency and arrangements. The latest additions fall under the species category; there is also a new "supplementary features" section of "unusual parts"—such as the aforementioned asperitas, a wavy look at the underside of a cloud—and five "special" clouds, including the contrail and clouds formed by waterfall fog. "Few natural phenomena" are as inspiring as clouds," notes WMO Secretary General Petteri Taalas. (Shifting cloud patterns are worrying.)