Atmospheric physics creates striking asymmetries in how sound travels

Evidence

Wind can also cause refraction effects because the velocity of sound within the medium is unaffected by the velocity of the medium. The velocity of a sound wave in a moving medium, when viewed from a fixed point, is the sum of the two velocities, so that it is increased when the sound is moving with the wind and is reduced when it is moving against the wind. As the velocity of air is generally less at ground level compared with the velocity higher up (due to the effect of the friction of the ground), sound waves are bent upward or downward depending on their direction relative to the wind. The degree of direction change depends on the rate of change in wind velocity as a function of height; a faster rate of change results in a greater direction change. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 340 (#exemplifies, via linked claim)

Categorization

  • XREF: connects to: The Strouhal relation predicts audible howls from ship shrouds but none from islands; Prevailing wind direction should guide where one lives relative to noise sources; Wind speed gradients, not wind itself, refract sound and break reciprocity (+9 more)

Broader Connections