Infrared remote sensing of breaking waves

ENERGY dissipation due to deep-water wave breaking plays a critical role in the development and evolution of the ocean surface wave field. Furthermore, the energy lost by the wave held via the breaking process is a source for turbulent mixing and air entrainment, which enhance ah-sea heat and gas transfer(1-3). But the current lack of reliable methods for measuring energy dissipation associated with wave breaking inhibits the quantitative study of processes occurring at ocean surfaces, and represents a major impediment to the improvement of global wave-prediction models(4). Here we present a method for remotely quantifying wave-breaking dynamics which uses an infrared imager to measure the temperature changes associated with the disruption and recovery of the surface thermal boundary layer (skin layer). Although our present results focus on quantifying energy dissipation-in particular, we show that the recovery rate of the skin layer in the wakes of breaking waves is correlated with the energy dissipation rate-future applications of this technique should help to elucidate the nature of important small-scale surface processes contributing to air-sea heat(5) and gas(6) flux, and lead to a fuller understanding of general of ocean-atmosphere interactions.