Wave-Coherent Fields in Air Flow over Ocean Waves: Identification of Cooperative Behavior Buried in Turbulence

Abstract

We present a method to study the coupling and synchronization of two chaotic systems---the surface gravity waves in the open ocean and the turbulent air flow above. Our approach employs an eikonal-like representation of the wave field based on the concept of an analytic signal and the Hilbert transform. We identify a wave-coherent component in the air flow which is phase locked with the waves and deeply buried in turbulence. That component contributes most of the wind-wave energy and momentum exchange, so its identification from actual data is of primary interest. We define and obtain the phase shifts of the wave-coherent fields and discuss their roles in the wind wave exchange.