Which atmospheric characteristic influences the speed of sound?

The speed of sound in the atmosphere is primarily influenced by temperature. As the temperature increases, the speed of sound also increases. This relationship occurs because sound waves travel through the air by causing particles to vibrate and pass energy from one particle to another. When air is warmer, the particles have higher kinetic energy and move more rapidly. This increased motion allows sound waves to propagate more quickly.

In contrast, at lower temperatures, the kinetic energy of air molecules decreases, which slows down the transmission of sound waves, resulting in a lower speed of sound. While other factors such as humidity, pressure, and density can have some effect on the speed of sound, the most significant and direct relationship is with temperature.

For instance, at a constant pressure, changes in humidity may slightly affect sound speed due to variations in the density of humid air compared to dry air. Similarly, while pressure can influence the speed of sound when temperature is held constant, in the atmosphere, temperature is the dominant factor, and thus the speed of sound changes primarily with fluctuations in temperature.