There Are Now Twelve New Types Of Cloud

By Holly Brockwell on at

The World Meteorological Organisation's International Cloud Atlas has added twelve new types to its list of recognised clouds, including one lobbied for by cloud appreciators (yes, really).

The physical version of the Atlas has existed since the 1800s, but has just gone digital with its first update since the 80s and is now accessible to the public as well as meteorologists. The new version has some exciting additions:

Several new, formal cloud classifications have been introduced. These include one new species (volutus), five new supplementary features (asperitas, cauda, cavum, fluctus and murus), and one new accessory cloud (flumen). The species floccus has been formally recognised as being able to occur in association with stratocumulus.

The separate section on Special Clouds has been removed, and the cloud and meteor types previously discussed within this section have been integrated into the cloud classification scheme as cataractagenitus, flammagenitus, homogenitus, silvagenitus, and homomutatus.

Asperitas is a particularly interesting addition: it was included after lobbying by the Cloud Appreciation Society.

Apparently the society themselves were surprised and delighted – president Gavin Pretor-Pinney tells the BBC:

"Back in 2008, I thought the chances of this becoming official were really minimal.

At first the WMO were saying they had no plans to do a new edition, but over time I think they began to realise there is an interest among the public in clouds and there is a need for that interest to be an informed one, there's a need for this authoritative work."

One of the reasons the database of cloud types is expanding is that smartphone photography has allowed more people to grab pictures of short-lived clouds and send them to the Cloud Appreciation Society. If you ever spot a really good one, here's where to send it. [BBC]

Main image: Pixabay