Von Karman vortex streets are the rows of alternating vortices shed off isolated objects interrupting a flow. Here, the volcanic peaks of Cabo Verde disrupt an atmospheric flow accustomed to an empty ocean. In a steady wind, air wraps around the volcanoes and detaches first on one side, creating a vortex, then from the other side, making a vortex of the opposite rotation. Although these structures are always present, we only see them when they stir up the cloud layer, leaving these strings of swirls for hundreds of kilometers behind the islands. (Image credit: L. Dauphin/NASA; via NASA Earth Observatory)
Strings of Swirls
