You may want to look up at the sky and observe a little more because the World Meteorological Organization just added 11 new clouds to the International Cloud Atlas, the world's definitive guide and database for cloud classification.

World Meteorological Day last March 23 also marks the publication of the new edition of the International Cloud Atlas. In this latest publication, the strange-looking, turbulent meteorological phenomenon asperitas is added to the list along with 10 other cloud formations.

Though many have seen and documented different cloud formations with the help of modern technology, it is only now that these formations are officially added to the list, a first in 30 years.

Perhaps one of the more mesmerizing phenomena in the list is the asperitas, formerly known as undulatus asperatus. It is characterized by the wave-like structures under the cloud formation, making it seem as though you are looking at the sea surface from below.

Incus

The incus is the upper portion of a cumulonimbus cloud formation that usually forms in the shape of an anvil.

Mamma

A mamma cloud formation's name is easy to understand. These formations are characterized by a set of hanging protuberances under the surface of the cloud, similar to bubbles or udders.

Virga

Streaks under a cloud formation characterize the virga. They occur mostly when trails of precipitation do not reach the surface of the Earth.

Fluctus

Formerly known as Kelvin-Helmholtz waves, the fluctus is a pretty short-lived cloud formation usually at cloud tops and have the appearance of breaking waves.

Other newly added cloud formations in the Atlas are the praecipitatio, arcus, tuba, cavum, murus, and cauda.

Citizen Science

The International Cloud Atlas was first made in 1896 and has since been an important resource for cloud formations. Meteorologists have relied on the atlas for decades of meteorological studies, and the influx of compact cameras have increased the data that meteorologists get to study. It is because of this data surge that after three decades, 11 highly documented cloud formations have been added to the atlas.

One of the more documented cloud formations, the asperitas, was first suggested by the Cloud Appreciation Society in 2008 when photos of the phenomenon were sent in by their members from all over the world. Now that asperitas is already an official part of the Atlas, the society believes that this will help people to appreciate our atmosphere and that it shows a perfect example of how technology and citizen science can influence the books.