The Evolution of the Speed of Sound Based on Changes of Entropy and Energy in Statistical Ocean

To develop geophysical fluid dynamics (GFD) from classical mechanics to thermodynamics or statistical mechanics, the "arrow of time", which is entropy, must be introduced. Entropy organizes the sound propagation in random ocean. With the help of flow velocity and temperature, this paper deduces the relationship between entropy, energy and the speed of sound under small-scale changes in the ocean. Simulations are performed with the space-time data of the three-dimensional rotating stratified turbulent flow of John Hopkins University, verifying deduced expressions, which is beneficial to the study of acoustic propagation and hence target detection, localization and tracking in the stochastic ocean.