2022 January 16

A Retreating Thunderstorm at Sunset
* Image Credit & Copyright: Alan Dyer (The Amazing Sky)
https://amazingsky.net/about/
https://amazingsky.net/

Explanation:
What type of cloud is that? This retreating cumulonimbus cloud, more commonly called a thundercloud, is somewhat unusual as it contains the unusual bumpiness of a mammatus cloud on the near end, while simultaneously producing falling rain on the far end. Taken in mid-2013 in southern Alberta, Canada, the cloud is moving to the east, into the distance, as the sun sets in the west, behind the camera. In the featured image, graphic sunset colors cross the sky to give the already photogenic cloud striking orange and pink hues. A darkening blue sky covers the background. Further in the distance, a rising, waxing, gibbous moon is visible on the far right.

https://apod.nasa.gov/apod/ap220116.html

#space #earth #atmophere #clouds #weather #photography #science #physics #meteorology #nature

Mammatus Clouds
* UCAR Center for Science Education

Mammatus clouds are pouches of clouds that hang underneath the base of a cloud. They are most often associated with cumulonimbus clouds that produce very strong storms. These clouds usually form during warm months, and are formed by descending air in the cloud. Mammatus clouds are sometimes described as looking like a field of tennis balls or melons, or like female human breasts. In fact, the name "mammatus" comes from the Latin word mamma, or breast.

CREDIT
Gregory Thompson

https://scied.ucar.edu/image/mammatus-clouds

#space #earth #atmophere #clouds #weather #photography #science #physics #meteorology #nature #education

2018 August 19

Asperitas Clouds Over New Zealand
* Image Credit & Copyright: Witta Priester
https://www.flickr.com/people/wittap/

Explanation:
What kind of clouds are these? Although their cause is presently unknown, such unusual atmospheric structures, as menacing as they might seem, do not appear to be harbingers of meteorological doom. Formally recognized as a distinct cloud type only last year, Asperitas clouds can be stunning in appearance, unusual in occurrence, and are relatively unstudied. Whereas most low cloud decks are flat bottomed, asperitas clouds appear to have significant vertical structure underneath. Speculation therefore holds that asperitas clouds might be related to lenticular clouds that form near mountains, or mammatus clouds associated with thunderstorms, or perhaps a foehn wind -- a type of dry downward wind that flows off mountains. Such a wind called the Canterbury arch streams toward the east coast of New Zealand's South Island. The featured image, taken above Hanmer Springs in Canterbury, New Zealand, in 2005, shows great detail partly because sunlight illuminates the undulating clouds from the side.

https://apod.nasa.gov/apod/ap180819.html

#space #earth #atmophere #clouds #weather #photography #science #physics #meteorology #nature #education

2009 January 21

A Lenticular Cloud Over New Zealand
* Credit & Copyright: Chris Picking (Starry Night Skies Photography)
http://www.starrynightphotos.com/about_me.html

Explanation:
What's happening above those mountains? Several clouds are stacked up into one striking lenticular cloud. Normally, air moves much more horizontally than it does vertically. Sometimes, however, such as when wind comes off of a mountain or a hill, relatively strong vertical oscillations take place as the air stabilizes. The dry air at the top of an oscillation may be quite stratified in moisture content, and hence forms clouds at each layer where the air saturates with moisture. The result can be a lenticular cloud with a strongly layered appearance. The above picture was taken in 2002 looking southwest over the Tararua Range mountains from North Island, New Zealand.

https://apod.nasa.gov/apod/ap090121.html

#space #earth #atmophere #clouds #weather #photography #science #physics #meteorology #nature #education

From Wikipedia, the free encyclopedia

Asperitas (cloud)

Asperitas (formerly known as Undulatus asperatus) is a cloud formation first popularized and proposed as a type of cloud in 2009 by Gavin Pretor-Pinney of the Cloud Appreciation Society. Added to the International Cloud Atlas as a supplementary feature in March 2017, it is the first cloud formation added since cirrus intortus in 1951. The name translates approximately as "roughness".

The clouds are closely related to undulatus clouds. Although they appear dark and storm-like, they almost always dissipate without a storm forming. The ominous-looking clouds have been widespread in the Plains states of the United States, often during the morning or midday hours following convective thunderstorm activity.

According to International Cloud Atlas, Asperitas are defined as

Well-defined, wave-like structures in the underside of the cloud; more chaotic and with less horizontal organization than the variety undulatus. Asperitas is characterized by localized waves in the cloud base, either smooth or dappled with smaller features, sometimes descending into sharp points as if viewing a roughened sea surface from below.
Varying illumination levels and cloud thickness can lead to dramatic visual effects.
Occurs mostly with Stratocumulus and Altocumulus.
[...]
For more Information see ALT-Text and:
https://en.wikipedia.org/wiki/Asperitas_(cloud)

#space #earth #atmophere #clouds #weather #photography #science #physics #meteorology #nature #education