The MODIS on the Aqua satellite captured this image of von Karmann cloud vortices off the coast of Cheju Do on December 25, 2008. Cheju Do is an island off the southwest coast of South Korea - it's nearly invisible here beneath the cloud cover.
The vortices are being formed by wind-driven clouds interacting with the highest point of the island, the 6400 foot Mt. Halla. The wind causes the clouds to flow around in the large, spinning eddies you see here. This is a fairly common occurrence for Cheju Do. Here are a few other MODIS images that show vortices off this island in February 2008 and January 2007.