Asperatus, Arcus, Mammatus: Strange Names For Unusual Clouds

Different clouds with strange names: exploring the fascinating world of cloud classification

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By Manu

asperatus clouds

Scientific names like arcus, altocumulus and mammatus, may sound bizarre, but they are the scientific names of clouds of rare and surreal shapes. Some can be really disturbing, so disturbing that superstitious people may think they are harbingers of the Apocalypse!

The sky is a beautiful canvas that showcases an ever-changing display of clouds. From fluffy white cumulus clouds to dramatic thunderheads, each cloud has its own unique structure and characteristics. In this article, we will dive into the world of cloud classification and explore some of the strangest named clouds, such as Asperatus, Arcus, and Mammatus.

These unique cloud formations add an element of mystery and fascination to the sky above.

Understanding cloud formation

The formation of cloud is determined by some rules of physics, such as the Kelvin-Helmholtz instability law.

This law states that a wave motion is created when two thermally stable fluids are superimposed and move at different speeds at their contact surface. The effect studied in the nineteenth century by the physicists Lord Kelvin and Hermann Ludwig von Helmholtz showed that the difference in speed will result in a cross-border turbulent flow.

Understanding cloud classification

Cloud classification is essential for meteorologists to predict weather patterns accurately and helps us identify and understand different cloud formations. In the International Cloud Atlas, clouds are grouped into main genera, including cirrus, cumulus, stratus, and nimbus.


Each genus is then further classified into species and varieties based on their appearance and characteristics.

Some unusual and surprising varieties of clouds

Here are some really curious specimens:

Asperatus Clouds: Waves in the Sky

Asperatus clouds are a very rare type of cloud. It was proposed to the International Cloud Atlas of the World Meteorological Organization in 2009 as a hitherto uncharted formation. Named after the Latin word for turbulent, agitated or even brutal depending on the context, Asperatus clouds are one of the most captivating and mysterious cloud formations.

With their undulating, rippled appearance, they resemble the waves of an angry ocean. Asperatus clouds often occur in turbulent atmospheric conditions and can be seen in various parts of the world, stirring the imagination of those who gaze upon them.

asperatus clouds
Asperatus clouds: turbulence coming.

Arcus Clouds: Rollin’ on the Horizon

Arcus clouds are low-level horizontal clouds that form along the leading edge of thunderstorms or squall lines. These unique clouds appear as a low, shelf-like formation, sometimes resembling a rolling wave or a menacing wall. Arcus clouds are associated with strong winds and can be a sign of an approaching storm. While they may look intimidating, arcus clouds provide a stunning visual spectacle in the sky.

Mammatus Clouds: A Quirky Appearance

Mammatus clouds are perhaps one of the most peculiar cloud formations. They are characterized by their distinct pouch-like structures that hang beneath a cloud base, resembling a field of upside-down bubbles or udders. Despite their unusual appearance, mammatus clouds are generally associated with the aftermath of severe thunderstorms and do not necessarily indicate severe weather. They create a mesmerizing sight and are admired for their unique beauty.

Tipi di nuvole

Noctilucent Clouds: Shining in the Night Sky

Noctilucent clouds, also known as polar mesospheric clouds, appear at high altitudes during the summer months in the Earth’s polar regions. These ethereal clouds shine brightly in the night sky, even when the sun is below the horizon. Composed of ice crystals, noctilucent clouds can display stunning colors ranging from silver to electric blue. Their formation is believed to be influenced by an increase in water vapor and dust particles in the upper atmosphere.

Lenticular Clouds: UFOs in Disguise

Lenticular clouds are often mistaken for UFOs due to their unusual saucer-like or lens shape. These stationary clouds form in the troposphere, typically at high altitudes near mountains or other elevated terrains. Lenticular clouds are caused by the flow of moist, stable air over obstacles, resulting in the condensation of water vapor. They can create a surreal and captivating sight, particularly when they stack up in a formation known as a “mother ship” cloud.

Contrails: Clouds from Jets

Contrails, short for condensation trails, are cloud-like formations created by the exhaust of jet engines at high altitudes. When the hot exhaust gases come in contact with the cold air, water vapor condenses into tiny ice crystals, forming long, thin trails behind the aircraft. Contrails can sometimes persist for hours and can spread, creating a hazy, streaked appearance in the sky. This curious phenomenon is the basis of the Chemtrail conspiracy theory.

While often seen as a sign of air travel, contrails can also have an impact on climate and weather conditions.

Nacreous clouds: A Dazzling Display in the Stratosphere

These clouds form in the stratosphere at an altitude between 15,000 and 25,000 meters. Nacreous clouds are rare and mostly form during the winter months near the poles. They were described by astronomer Robert Leslie in 1885. Involved in the formation of holes in the ozone layer, they support the chemical reactions that produce molecules of chlorinated compounds. These molecules serve as a catalyst for the reaction destroying ozone molecules.

A conclusion: Cloud classification is a fascinating field that allows us to appreciate the diverse beauty and wonders of the sky above. Asperatus, Arcus, Mammatus, Noctilucent, Lenticular, and Contrails are just a few examples of the strange and captivating cloud formations that grace our atmosphere. These clouds add a touch of magic to our skies, reminding us of the ever-changing nature of our environment. So next time you look up at the clouds, keep an eye out for these extraordinary and uniquely named formations.

Really amazing, don’t you think?

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