This is Bird Note. When we watch birds, they're often in flight. Snow geese.

A soaring Swainson's hawk. But behind the birds are often clouds of puffy white, or wispy checkerboards, or masses of lead and silver rolling headlong across the sky.

Sometimes the clouds themselves are so dramatic, they pull on our attention as much as the creatures winging by.

Much like birds, clouds have been a subject of artistic reflection and scientific inquiry.

And for more than 200 years, types of clouds have been organized in ways very similar

to types of birds, to help watchers recognize and enjoy them.

2017 marked a key event in cloud watching. After a decade of research and discussion, the

scientists at the World Meteorological Organization

added the Asperitus Cloud to their international Cloud Atlas.

With the online Atlas, you can quickly figure out if you're watching those geese flying in front

of a nimbus or a stratus, or maybe even the massive dark folds of the newly named Volutus cloud.

Now you can make your cloud watching even more like bird watching.

For Bird Note, I'm Michael Stein.