Enhancing marine acoustic field prediction in shallow seas using an ocean-sediment coupled model

Marine acoustic field prediction (MAFP) is essential for a variety of application scenarios. Given the rapid temporal changes in the ocean environment, MAFP requires time-dependent acoustic parameters. Ocean models are generally employed to provide dynamic acoustic parameters for the water column; however, few models extend this capability to sediments. Nonetheless, both observations and simulations have revealed that sediment temperature variations in shallow seas significantly affect the sediment acoustic properties. This paper proposes conducting MAFP using an ocean-sediment coupled model, which integrates the water column and sediment through the ocean bottom heat flux process, enabling simultaneous modeling of both the sediment and water temperatures. The MAFP results from an ocean-only model are compared with those of the ocean-sediment coupled model. The findings indicate that the coupled model enhances the MAFP in two significant ways. First, it provides a time-varying sediment temperature field, allowing the use of temperature-sensitive sediment acoustic parameters that evolve over time. Second, it yields a more accurate water temperature profile. These enhancements could significantly reduce MAFP errors, underscoring the critical role of the coupled model, particularly in shallow-water environments.