Revamped atlas to give clouds their day in the sun

Rand-McNally covers roads, Gray’s takes care of anatomy and Webster's deals with the written word, but who keeps track of all the clouds?

That responsibility falls to the International Cloud Atlas. For more than a century the book has served as the world's official bible of those masses of water particles that form all sorts of shapes — everything from the puffy cumulus to the dark and ominous cumulonimbus.

Now, the ancient atlas is getting a serious makeover for the 21st century with its first edition since the 1970s and 1980s.

“It hasn’t been updated since the world became digital,” said Steve Cohn, a meteorologist who’s helping put together the new version. "We want to bring it into the modern age and make it more accessible to everyone."

The roots of the creaky book date to the 19th century, when the first one containing 28 color pictures was published in 1896. The most recent full text edition came out in 1975, with a companion book of images in 1987.

Weather observers worldwide have used the atlas to ensure clouds are described in a uniform fashion, according to Weather Underground meteorologist Robert Henson.

Up until a year ago, the book was only available on printed volumes through the World Meteorological Organization (WMO), which is in charge of naming and cataloging clouds. The most recent edition can now be downloaded as a PDF, Cohn said.

The new version, which is being worked on by a team of professional meteorologists who are experts on observing clouds, is scheduled for release next year.

What's your type?

Clouds are classified into various levels using Latin: Genus (level 1), species (level 2), variety (level 3) and supplementary features and special clouds (level 4). This is the same way that scientists describe the plant and animal kingdoms, according to Cohn.

There are 10 basic classifications (genus) of clouds:

• High clouds: Cirrus, Cirrocumulus and Cirrostratus
• Middle clouds: Altocumulus, Altostratus and Nimbostratus
• Low clouds: Stratocumulus, Stratus, Cumulus and Cumulonimbus

These 10 types are then subdivided into 14 species (secondary classifications), which describe their shape and internal structure, and nine varieties (tertiary classifications), which describe their transparency and arrangement.

In addition to these first three levels, certain supplementary features and accessory clouds are also defined in a fourth level of description.

Thus, a single cloud can have an extremely long name, such as: Stratocumulus stratiformis translucidus perlucidus or Cumulonimbus capillatus praecipitatio arcus.

Though no new genus-level clouds will be in the updated atlas, cloud-watchers are excited by one new species that will: Volutus (Latin for rolled), is a solitary roll cloud, which in Australia is known as the morning glory cloud.

Some supplementary features are also under consideration, including asperitas (rough), which got a boost from the the U.K.'s Cloud Appreciation Society in recent years. This looks like a surreal undulating blanket that covers part or all of the sky.

While obviously not a "new" cloud, asperitas only gained widespread attention with the advent of phone cameras, the Internet and social media.

'New' cloud to have its day in the sun

Some other recommended new accessory and special clouds include flumen (river), cataractagenesis (formed by a waterfall), flammagenitus (formed by fire; commonly known as pyro-, but that's Greek, not Latin), homogenitus (manmade, such as contrails), silvagenitus (caused by a forest) and homomutatus (mutated from a manmade cloud).

Your help is needed

What's also different this time around is that the WMO is asking for photos and videos of clouds from the public for possible inclusion in the new volume.

"The more the merrier" said Roger Atkinson, a science officer at the WMO who is also working on the atlas. "Response from USA has not been as strong as we'd hoped."

Your best shot at getting your image included in the atlas is to submit photos of rare clouds.

Atkinson said the new atlas is scheduled for release online on March 23, 2017. That date happens to be World Meteorological Day, whose theme for 2017 is "Understanding Clouds."

Eventually, a printed version of the book will be made available, Atkinson said.

"Ultimately I think we'll have a coffee table version, too," he said.