Oceanic Hot Spots - Internal Tides in the Global Ocean

The ocean flows and undulates in response to wind stress, heating and cooling, and the gravitational attraction of the Sun and Moon. For the first time, Naval Research Laboratory scientists, in collaboration with university colleagues, have simulated ocean tides concurrently within the ocean circulation over the entire globe at very high resolution.1 The surface tides interact with bottom topography to generate internal waves. Surprisingly, the strongest internal tide generation is not where the surface tides are the largest. The strongest interactions occur in limited regions, oceanic internal wave hot spots. The internal waves radiate away from the hot spots as focused beams, which propagate for thousands of kilometers, and are an important source of energy for mixing the ocean interior. Both the ocean circulation and the tidal flow of the model compare well to a new set of global observations consisting of satellite altimeter tidal heights, historical moored current meters, and drifting buoys. The new model allows estimates of the ocean currents and tidal elevations anywhere on the globe at any time.