Oceanic vortices. Animation showing ocean surface relative vorticity, simulated by the Parallel Ocean Program (POP). Vorticity, or rate of fluid rotation, is useful for visualizing ocean turbulent flow. These turbulent motions are an important factor in distributions of energy, heat, salt, and chemical constituents (such as carbon dioxide) across the globe. Green indicates eddies rotating in the same direction as the earth and orange indicates rotation in the opposite direction. The darker the color, the stronger the rotation. The strongest eddies are typically associated with instabilities of sea surface currents, such as the Gulf Stream off the east coast of the United States.