Ocean waves in the sky?
WGN’s Tom Skilling shared a startling photograph on his Facebook page Saturday of what looks like ocean waves in the cloud formation over Lake Michigan.
As Tom explains:
This was the scene yesterday morning off Leland in northern Lower Michigan–237 miles northeast of Chicago. What look like ocean waves were showing up in this cloud formation situated out over Lake Michigan. Mark King snapped this amazing photograph and relayed it to us (THANK YOU, Mark!!) It was taken west of Traverse City.
Skilling goes on to explain:
The wave pattern observed here is the result of what is known as a “Kelvin-Helmholtz instability” brought on by a vertical variation in wind speeds through the atmosphere—i.e. winds are moving faster at one level of the atmosphere than another. The so-called “speed shear” underway in this instance has set up a situation in which “eddies”form——eddies we see here in the form of waves in these clouds.
He says the wave formation “can occur in any fluid.The air in our atmosphere behaves like a fluid and fluid dynamics equations allow computer simulations of what’s going on here such as in this computer animation of the formation of Kelvin-Helmholtz waves.”
For more on the Kelvin-Helmholtz instability and the waves which result, this is a fascinating article with stunning examples of other Kelvin-Helmholtz waves: http://earthsky.org/earth/kelvin-helmholzt-clouds