Modeling of acoustic waveguides in floating ice sheets with vertical temperature profiles

Area of Science:

• Acoustics
• Geophysics
• Materials Science

Background:

• Arctic sea ice is often modeled as a uniform layer for acoustic analysis.
• Environmental factors, especially temperature, significantly alter sea ice's acoustic properties over time and space.

Purpose of the Study:

• To develop a more accurate acoustic model for Arctic sea ice that accounts for temperature-induced variations.
• To investigate the impact of vertical temperature gradients on sound propagation velocity within sea ice.

Main Methods:

• A virtual stratification technique was employed to represent temperature variations within the ice.
• An empirical model was created using experimental data linking propagation velocity to temperature.
• A nested matrix method was developed to model the air-ice-water system with virtual ice sublayers.

Main Results:

• The virtual stratification model accurately captured sound propagation variations due to temperature differences.
• The proposed model outperformed the traditional monolayer model based on effective medium theory.
• Analysis of stratification protocols (equal thickness vs. equal velocity change) provided insights into optimal model configurations.

Conclusions:

• Environmental factors, particularly temperature, are crucial for accurate acoustic modeling of Arctic sea ice.
• Virtual stratification is an effective method for incorporating vertical temperature changes into acoustic waveguide models.
• Future work should consider additional complexities like snow layers for enhanced model fidelity.