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Updated: Sep 18, 2025
09:36
Continuous-Wave Propagation Channel-Sounding Measurement System - Testing, Verification, and Measurements
Published on: June 25, 2021
3.2K
North Atlantic upper ocean sound channel variations.
Gregg A Jacobs1, Robert W Helber1, John M Toole2
1Naval Research Laboratory, Stennis Space Center, Mississippi 39529, USA.
The Journal of the Acoustical Society of America
|June 23, 2025
Summary
Sound channels in the North Atlantic are linked to specific water masses and locations. Improved ocean models better represent these sound channels and their associated water properties.
Area of Science:
- Oceanography
- Acoustics
- Numerical Modeling
Background:
- Sound channels are crucial for underwater acoustics and are influenced by oceanographic conditions.
- Understanding sound channel distribution aids in assessing numerical ocean model performance.
- Previous studies have characterized general sound channel behavior, but detailed regional analysis is needed.
Purpose of the Study:
- To characterize sound channel distributions in the North Atlantic Ocean.
- To investigate the relationship between sound channels and water masses.
- To evaluate the performance of numerical ocean models in simulating sound channels.
Main Methods:
- Analysis of historical profile observations of sound channels.
- Focus on sound channels above 500m depth, below the sonic layer, with cutoff frequencies < 200Hz.
- Comparison of observed sound channel occurrences and water mass properties with numerical model outputs.
Main Results:
- Sound channels frequently occur near the Rockall Trough, Reykjanes Ridge, Labrador Current, and Gulf Stream.
- Higher sound channel occurrences are observed in spring and summer due to shallower sonic layers.
- Sound channel axes show lower salinity, indicating subduction of cold, low-salinity surface waters.
Conclusions:
- Numerical ocean model resolution (vertical and horizontal) significantly impacts the accuracy of simulated sound channel occurrence rates and water mass properties.
- Subsurface cold, low-salinity waters are influenced by processes like isopycnal subduction and winter convection.
- Model deficiencies need further consideration in relation to water mass distributions and physical oceanographic processes.
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