 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.  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 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."  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. 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 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). 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. 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.
– 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.)