Depth-dependence and vertical directionality of wind-driven ambient noise in deep ocean

The received wind driven noise field can be described as a sum of fields radiated from many random sources on the sea surface. Wind driven noise source levels can be modeled by empirical relationship with local wind speed. A method for modeling wind-driven ambient noise based on ray approach in deep ocean is presented. Simulations are performed to demonstrate the validity of the method. The wind-driven ambient noises are attributed to not only the near noise sources but also distant noise sources. The depth dependence and vertical directionality of ambient noise caused by wind agitation are analyzed by using the proposed modeling method, and vertical directionality frequency dependence is also described. In addition, the relationship between the logarithm of wind speed and noise levels is also analyzed at near surface and bottom depth. The power of wind speed with respect to received noise levels is equal to that of wind speed with respect to noise source levels approximately.