A rare cloud formation, called Kelvin-Helmholz waves, glides across the Victorian Alps, Australia. Kelvin-Helmholz waves are formed as two layers of air with different densities move past each other at different speeds. Just like ocean waves, the crests of Kelvin-Helmholz waves will crash as the air layer on top moves faster than the air layer on the bottom.

Photograph by Mark Pendavingh, My Shot

Download this file

Oh no! It appears that there was an error with your submission. Care to try again?

Coming soon!

You've found a feature that is not available.

Get notified when this feature is available

Our media can be used in a variety of contexts—from media spotlights to encyclopedic entries to lessons. From this page, check out the different ways you can use this .

Other Pages That Use This Item

cloud
cloud Encyclopedic Entry

Best For
5 - 12 and up

Subjects
Geography, Science

Appropriate For

  • Educators
  • Families
  • Students

Clouds are visible accumulations of tiny water droplets or ice crystals in the Earth’s atmosphere