Characterization and source level modeling revision of the wind-generated ambient noise in South China Sea

Based on the long-term observation noise and synchronous wind speed data in the deep water of the South China Sea in autumn 2015,the characteristics of the wind-dominated ambient noise are analyzed and the source level models at different wind speeds are modified.The results of data processing show approximate quadratic noise-wind speed dependence in frequency range of 0.5-3.2 kHz when the local wind speed exceeds 3 m/s.The ambient noise spectrum levels averaged in the different wind speeds are obtained based on the relationship.Based on ray theory,a numerical modeling of ambient noise field in deep water is established.The wind source level formula is revised by minimizing the deviation between experimental noise spectra and numerical results at the wind-dominated frequency band,and the applicable frequency band is expanded to twice ford.In the end,the revised model is verified by comparing the forecasted noise spectra with the experiment data measured from another site in 2016.The model might be used to forecast the ambient noise level in the South China Sea from marine meteorological forecast.