Vertical Correlation and Directionality of Ambient Noise in Deep Ocean

Wind-driven and distant shipping noise sources may significantly and simultaneously affect the spatial characteristics of the total noise field to some extent in deep ocean. In this paper, a standard ray approach and parabolic equation solution method were jointly utilized to model the low-frequency ambient noise field in a range-dependent deep ocean environment. The reanalysis databases of National Center of Environment Prediction (NCEP) and Volunteer Observation System (VOS) were used to model the ambient noise source intensity and distribution in South China Sea. Spatial vertical directionality and correlation were analyzed in three scenarios that correspond to three wind speed conditions. Furthermore, the vertical characteristics of low-frequency ambient noise field were compared with the Cron/Sherman deep water noise field coherence function. Simulation results with the described modeling method showed good agreement with the experimental measurement results based on the vertical line array deployed in deep ocean.