Marine Layer and Kelvin–Helmholtz Instability Clouds

October 05, 2012

Mila KelvinHelmholtz instability

: Mila Zinkova; Mila’s Web site
Summary Authors: Mila Zinkova; Jim Foster

The photo above showing a well-stratified marine cloud layer, backlit by the Sun, was taken a little before sundown off the coast of California, near San Francisco. Just below the stable marine layer are the rippled signatures of Kelvin-Helmholtz instability clouds. These waves take shape within a stable layer of air subjected to vertical wind shear. They typically appear as sharpened curls that dip into regularly spaced pockets of turbulence, but the curls shown here look upside down to those normally observed. Photo taken on July 6, 2012.

Photo details: Camera Maker: Canon; Camera Model: Canon PowerShot SX40 HS; Focal Length: 43.1mm; Aperture: f/5.0; Exposure Time: 0.0080 s (1/125); ISO equiv: 200; Exposure Bias: none; Metering Mode: Matrix; White Balance: Auto; Flash Fired: No (enforced); Orientation: Normal; Color Space: sRGB; Software: Adobe Photoshop CS3 Windows.