What factor influences the local speed of sound (LSS)?

The local speed of sound (LSS) is significantly influenced by temperature. As temperature increases, the speed of sound in air also increases. This is because sound waves travel through the air by causing air molecules to vibrate, and higher temperatures provide more kinetic energy to these molecules, allowing them to move more quickly. Conversely, at lower temperatures, the kinetic energy of the molecules is reduced, resulting in a slower speed of sound.

The relationship between temperature and the speed of sound is given by the formula:

[ c = \sqrt{\gamma \cdot R \cdot T} ]

where ( c ) is the speed of sound, ( \gamma ) is the adiabatic index, ( R ) is the specific gas constant, and ( T ) is the absolute temperature in Kelvin. This equation illustrates how the speed of sound is directly proportional to the square root of the temperature.

Other factors such as altitude, humidity, and air pressure do have effects on the properties of the air and can indirectly influence the speed of sound, but they are often secondary compared to the dominant effect of temperature. For instance, while altitude affects both pressure and temperature, the temperature change is the primary driver for variations in the speed of