Thursday, March 23, 2017

Check Out the Sky



Stunning 'new' cloud formations captured in updated atlas – in pictures

Roll clouds and wave-like asperitas are among the additions to the new digital International Cloud Atlas, that dates back to the 19th century. It features hundreds of images captured by meteorologists and cloud lovers from around the world

The Guardian  23 March 2017


These rare wave-like asperitas clouds – photographed here in Great Harrowden, in the East Midlands – have long been seen by cloud enthusiasts but never formally classified, until now. Photograph: Joanne Kelly/WMO

 
Asperitas is characterized by wave-like structures in the underside of the cloud. Here undulatus is developing into asperitas in Cope, US. Photograph: Paulette H Wright/WMO

 
A newly classified Stratocumulus volutus, or roll cloud, with Cumulonimbus capillatus incus paecipitatio in the background, Wakulla County, Florida, US. The cloud atlas was last revised in 1987 and is used by cloud enthusiasts and meteorologists to help predict the weather. Photograph: Christy Gray/WMO

 
Roll clouds in Szprotawa, Poland, Photograph: Mirosław/WMO

 
Roll clouds over western Poland. The new atlas brings together all types of measurements – including high-tech space observations and remote sensing – for the first time.  Photograph: WMO

 
Aircraft condensation trails or contrails, (Cirrus homogenitus), Wokingham, England, UK, another of the new classifications in the atlas   Photograph: George Anderson/WMO

 
A fallstreak hole or hole-punch cloud (cavum) within a thin and extensive layer of cloud (Altocumulus stratiformis translucidus). In addition, in the top part of the picture is the variety perlucidus, due to the gaps between the cloud elements. The full classification for the cloud is therefore Altocumulus stratiformis perlucidus translucidus cavum. Photograph: Lee Tsz Cheung/WMO

 
Stratocumulus cumulogenitus homogenitus. Rising thermals from the Prunéřov, Tušimice and Počerady power plants in the Czech Republic, have generated Cumulus congestus homogenitus clouds which have spread out to form Stratocumulus at a height of about 2500m. As the Stratocumulus has formed by the spreading of Cumulus, the mother-cloud term cumulogenitus applies. The name homogenitus applies as the clouds formed as a consequence of human activity.  Photograph: Karlona Plskova/WMO


A magnificant halo display is formed by the refraction and reflection of sunlight through diamond dust at an altitude of 1100m on Mount Keilberg in the Ore mountains on the German/Czech border. Such complex displays are usually observed only in polar regions although, as in this case, they may occasionally occur in mountains when there are ice crystals in the air. Photograph: Claudia Hinz/WMO

 
A primary rainbow with a series of extra, or supernumerary bows inside it, Hinuera, Waikato, New Zealand. Photograph: Pam Gore/WMO

 
This funnel cloud developed from the base of cumuliform cloud (Cumulus congestus or Cumulonimbus), associated with a trough, in a showery northerly airflow over Northumberland, northeast England, UK. All tornadoes begin with the development of a funnel cloud which subsequently reaches the ground but cold-air funnels, such as this, arise from localised convective and shear vortices and are not associated with larger scale mesocyclones. Photograph: Stephen Lewins/WMO

 
This image shows the Campo, Colorado, tornado of 31 May 2010 in its early stages. The tornado had just touched down, formed underneath a large wall cloud (murus). Photograph: Matthew Clark/WMO


A Fata Morgana mirage over Monterey Bay, California, US. A Fata Morgana is a very complex mirage formed on land or at sea, and may involve various types of distant object, including ships, islands, coastlines, icebergs and clouds. A strong thermal inversion is required, with warmer air over cold air, in which an atmospheric duct is formed. Photograph: Mila Zinkova/WMO


The term ‘Crepuscular rays’ normally refers to dark bluish streaks and light beams radiating from the sun across the twilight sky. The the name is also used to refer to the shadowed bands and light beams which diverge from the sun, at any time of day, when it is hidden behind cloud, such as these in Wokingham, England, UK Photograph: George Anderson/WMO

 
The base of a Cumulonimbus capillatus cloud is partly obscured by precipitation and virgo – additional precipitation trails, illuminated by late afternoon sunlight that are evaporating before reaching the surface. Nadderwater, Exeter, Devon, UK Photograph: Matthew Clark/WMO

 
‘Anvil crawler’ lightning during a thunderstorm in Lincoln, Nebraska, US. Photograph: Matthew Clark/WMO


A spectacular example of Altocumulus lenticularis duplicatus in Iceland. There are multiple stacked lens or almond shaped patches, increasing in size with height. The mountain waves responsible for this cloud are also reflected in the extensive layer of undulating Altostratus above the lenticularis clouds. Photograph: Gréta S. Guðjónsdóttir/WMO


Cumulonimbus are heavy, dense clouds in the form of a mountain or huge towers, such as these in Pace del Mela, Messina, Italy. At least part of the upper portion is usually smooth, or fibrous or striated and nearly always flattened. The cloud base is often very dark. In this image, the upper portions have a cirriform appearance identifying the species as capillatus and an anvil is in the early stages of development which is the supplementary feature incus. Photograph: Fabrizio Micalizzi/WMO


Waterspouts in Cetraro, Italy. A waterspout is a type of spout or tornado that occurs over water. The rotating spouts consist of a condensation funnel in contact with the water and of a ‘bush’ composed of water droplets raised from the surface of the sea. Photograph: Francesco Pepe/WMO

 
Stratocumulus fluctus Fluctus in Laukvik, Norway. This is a relatively short-lived wave formation on the top surface of a cloud that takes the form of curls or breaking waves. Photograph: Mrs June Grønseth/WMO


Altocumulus lenticularis clouds form over and immediately to the lee of the Yorkshire Pennines in the UK. Photograph: Matthew Clark/WMO


Low level Cumulus, middle level Altocumulus and high level Cirrus in Honolulu, US. The predominate cloud is Altocumulus floccus (small cumuliform tufts) from which fibrous trails of ice crystal virga are falling. Photograph: Mok Hing Yim/WMO

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