How to detect the weather through sound?

Sound is the human ear’s perception of the density and density of air molecules in the atmosphere. For example, when we ring a bell, the bell is struck and vibrates. This vibration pushes the nearby air molecules, causing them to change in density. This periodic change in density spreads in the air. , forming a sound wave. When sound waves reach our ears, we hear the sound of a bell.

In recent years, research on using sound to detect the atmosphere has attracted people's attention. As early as 1901, people discovered that about 70 to 90 kilometers away from the area where the shell exploded, there was a quiet zone where explosions could not be heard. Outside of this quiet zone, there was an area where explosions could be heard. During World War I, this phenomenon attracted even more attention. Many pickups were placed at different distances around the explosion site to receive the sound of the explosion in order to study the propagation phenomenon of this abnormal sound wave. During World War II, people also used rockets to bring explosives to explode at high altitudes, and used ground pickups to detect them. These detections have proven that there is a high-temperature area about 50 kilometers high in the sky. The emergence of the quiet zone is due to the refraction of sound waves when they propagate at high altitudes.

But in recent years, equipment that uses sound waves to detect the atmosphere mainly uses sodar. Sodar can measure changes in atmospheric temperature and humidity with altitude and their tiny pulsations 1 to 2 kilometers below the ground. It can also measure wind direction, wind speed, frontal structure, convective thermal airflow, temperature inversion layer, etc.