Modeling mode arrivals in the 1995 SWARM experiment acoustic transmissions

Area of Science:

• Oceanography
• Acoustics
• Wave Propagation

Background:

• The Shallow Water Acoustics in a Random Medium (SWARM) experiment investigated acoustic propagation.
• Shelf-generated internal wave solitons create complex acoustic environments in shallow waters.
• These solitons cause significant energy coupling between acoustic modes, leading to signal fluctuations.

Purpose of the Study:

• To model and understand acoustic propagation and scattering in waveguides influenced by internal wave solitons.
• To compare the effectiveness of two different modeling approaches for simulating these phenomena.

Main Methods:

• Utilized the Sudden Interface Approximation (SIA) to model internal wave solitons.
• Employed a finely meshed, "propagated" thermistor record to simulate solitons.
• Analyzed acoustic scattering characteristics observed in the SWARM field data.

Main Results:

• Both modeling methods generated scattering characteristics consistent with SWARM field data.
• The Sudden Interface Approximation provided a computationally efficient way to represent solitons.
• The propagated thermistor record offered a detailed, albeit slower, simulation.

Conclusions:

• Numerical modeling can effectively replicate the acoustic scattering caused by internal wave solitons.
• The chosen methods provide valuable tools for understanding acoustic propagation in dynamic ocean environments.
• Findings contribute to improved acoustic modeling for oceanographic research.