⚡ AnythingOnline
🐬
SOFAR Channel Sound Speed Calculator engineering
100% Free • No Sign-Up

SOFAR Channel Sound Speed Calculator

Physical oceanography & underwater acoustics: Compute seawater sound velocity profiles (Mackenzie 9-term equation), SOFAR channel waveguide axis, and ray bending curvature.

Ocean Hydrographic Parameters

Depth below sea surface
In-situ water temperature
Practical Salinity Scale
Local vertical gradient (m/s per m)
Grazing angle relative to horizontal
Minimum sound channel axis speed

Acoustic Propagation & Waveguide Analysis

In-Situ Sound Speed (c)
-
Mackenzie (1981) 9-term formula
Ray Curvature Radius (R)
-
-
Ray Turning Sound Speed (c_turn)
-
c_turn = c / cos(θ₀) (horizontal apex)
Critical Angle at Channel Edge
-
Snell acoustic trapping limit
Snell's Constant (a)
-
cos(θ) / c (invariant along ray)
Hydrostatic Pressure
-
~0.101 bar/m depth

Recommended Tools & Equipment

Tested hardware and components for high reliability

100% Free Tool Zero Sign-Up

Frequently Asked Questions

Why does sound speed reach a minimum at the SOFAR axis?

Sound speed in seawater depends primarily on temperature, salinity, and pressure. Near the surface, temperature drops steeply through the main thermocline, causing sound speed to decrease. At greater depths, temperature is nearly constant, but hydrostatic pressure increases steadily, driving sound speed upward. The balance creates an acoustic minimum known as the SOFAR axis.

How does Snell law explain ray bending in seawater?

Because sound speed varies with depth, the wavefront travels faster in the higher-speed region, causing the wave vector to turn toward the lower sound speed region. Acoustic energy is continuously focused back toward the sound channel axis.

What is the practical use of the SOFAR channel?

The SOFAR channel is utilized for global ocean acoustic tomography, hydroacoustic monitoring of clandestine nuclear tests (CTBTO IMS network), long-range underwater navigation for autonomous underwater vehicles (AUVs), and marine mammal bioacoustic tracking.