Modelling sound particle motion in shallow watera).

Area of Science:

• Acoustics
• Marine Biology
• Environmental Science

Background:

• Marine organisms, including fish and invertebrates, exhibit sensitivity to underwater sound particle motion.
• Understanding the acoustic environment is crucial for assessing the impact of anthropogenic sound on marine ecosystems.
• Existing models for underwater sound propagation require verification and benchmark cases for reliable application.

Purpose of the Study:

• To propose benchmark cases and solutions for selecting and verifying sound particle motion models.
• To facilitate accurate modeling of underwater sound's impact on marine life.
• To provide a framework for evaluating the performance of acoustic models in marine environments.

Main Methods:

• Development of benchmark scenarios for acoustic modeling.
• Inclusion of range-independent environments with and without sediment shear.
• Inclusion of range-dependent environments without sediment shear.
• Analysis of acoustic impedance to relate sound particle velocity and pressure fields.

Main Results:

• Benchmark cases were established for model verification.
• The study analyzed scenarios with varying environmental complexities (range-independence, sediment shear).
• Acoustic impedance analysis revealed conditions for estimating particle velocity from pressure fields in shallow water.

Conclusions:

• The proposed benchmark cases are essential for validating underwater acoustic models.
• Accurate sound particle motion modeling is vital for marine life impact studies.
• Sound particle velocity can be estimated from sound pressure in specific shallow water conditions, with noted exceptions near the source and at low frequencies.