Nature: The Sun had been thought to be the primary warming influence on the water in shallow coastal areas, from coral reefs to Arctic shorelines to popular beaches. However, using data gathered from buoys and sensors, Gregory Sinnett and Falk Feddersen of the Scripps Institution of Oceanography in La Jolla, California, have found that ocean waves contain more heat than they expected. Although the Sun is responsible for a lot of it—particularly in places like southern California, where Scripps is located—breaking waves generate a surprising amount of heat, which results from the energy created by the forces of friction. Even in predominantly cloudy areas like the Pacific Northwest, considerable heat can still be imparted to the water by the stronger wave action. The unexpected heat source, some researchers suggest, may be exacerbating the coastal erosion that is occurring in Arctic Alaska, where loss of sea ice and more open water have led to more wave action.
