von Karman Vortices
April 30, 2002
This satellite image shows von Karman vortices, which have formed over the Kuril Islands of Japan - south of Russia's Kamchatka Peninsula. The image was acquired by the Landsat-7 satellite using the Enhanced Thematic Mapper sensor on May 6, 2000. Von Karman vortices are named after Theodore von Karman (co-founder of NASA's Jet Propulsion Laboratory), who first described the phenomenon. These vortices form just about anywhere that fluid flow is interrupted by an object. On the above image, several of the Kuril Islands are causing the interruption. When vigorous wind-streams encounter an island, a low level disturbance is created, which may be propagated down wind in the form of linear chains of spiral eddies. These eddies or vortices alternate their direction of rotation as the fluid flow moves downstream.