The Noise Office receives many noise complaints from residents who notice that airplane noise is much worse on one day versus another. Generally, the amount of noise emitted from a particular jet aircraft during landing, departure, or engine testing does not change from day to day. However, several factors may affect the sound level heard by an individual at a given location. It should also be noted that one’s perception of noise varies among individuals. Noise circulation is a complex phenomenon that can be influenced by wind, temperature, cloud cover, fog, topography, and man-made barriers such as homes and other buildings.
Noise is essentially a sound wave distributed in equal directions away from the source. Generally, noise levels decrease as the distance increases between the source and the receiver. However, the direction in which the sound waves travel can be altered by weather conditions, which may result in varying noise levels at the same location at different times. For example, during Tampa’s afternoon thunderstorms, cloud cover tends to bend sound waves downward toward the ground and that can increase the sound heard by a receiver. Inversions, which occur when the air temperature increases as altitude increases, have the same effect on noise as does cloud cover. These types of weather conditions slow the atmospheric absorption of the noise waves and may cause jet aircraft noise to sound louder.
Wind is another factor that generally causes sound waves to bend in the direction it flows. As in this region, winds are generally from the northeast or southwest and planes takeoff and land into the direction of the wind. When this occurs, residents on either side of the flight path may hear changes in noise levels. These differing conditions do not cover all the possibilities, but provide an indication of how weather may alter the circulation of sound waves.