Explore the phenomenon of what is thunder, uncover its underlying nature, and delve into intriguing details about its characteristics.
Thunder, the audible consequence of lightning, arises from the rapid expansion of the air enveloping the path of the lightning discharge. But what exactly is the nature of thunder and how does it connect to lightning?
What is thunder?
As lightning courses from the clouds to the nearest point on the ground in mere fractions of a second, the subsequent resounding thunder might be attributed to the lightning itself. However, the rolling and growling auditory experience encountered in the midst of a thunderstorm originates not from the lightning directly, but rather emerges from the swift expansion of the air encircling the lightning channel.
The process unfolds when lightning establishes a connection between the clouds and the earth’s surface. This connection prompts a return lightning strike to travel through the same conduit as the initial discharge. As this return strike’s electrical energy generates intense heat, the surrounding air temperature escalates dramatically, soaring to approximately 27,000 degrees Celsius (48,632 degrees Fahrenheit).
This heightened temperature in turn triggers a rapid surge in air pressure, elevating it by a magnitude of 10 to 100 times compared to the customary atmospheric pressure.
A captivating facet of thunder’s formation centers around the principle of pressure and the interaction with heated air. Under the duress of elevated pressure, heated air surges out of the conduit, compelling the compression of the surrounding air.
As the heated air expands, a subsequent drop in pressure unfolds, leading to air cooling and further compression. This intricate interplay culminates in the generation of a shock wave, culminating in a resonant, rumbling explosion of sound that reverberates in all directions.
The intricacies of thunder’s auditory profile are further influenced by the geometry of lightning strikes. Given that electricity tends to follow the shortest route, the majority of lightning discharges occur in a vertical orientation. Consequently, the shock waves produced closer to the ground reach the human ear before those traveling upwards, thus producing the characteristic long, rumbling sound commonly associated with thunder.
Yet, a divergence in the path of lightning can bring about distinctive auditory effects. When lightning forks into multiple branches, the shock waves emitted from these various forks interact with each other, as well as with obstructions such as low-hanging clouds and nearby hills. This interaction leads to the creation of a series of interconnected, lower-pitched and continuous rumbles that collectively contribute to the soundscape of thunder.
Interesting facts about thunder:
- To gauge the proximity of a lightning strike, simply count the seconds between witnessing the lightning flash and hearing the clap of thunder. Each second roughly corresponds to a distance of 300 meters (about 984.25 feet).
- Thunder, intriguingly, isn’t limited to thunderstorms alone. On occasion, and rather surprisingly, thunder can be heard during episodes of snowfall.
- Counter to intuition, lightning doesn’t invariably engender thunder. An incident in April 1885 recorded five instances of lightning striking the Washington Monument during a thunderstorm, yet no audible thunder resonated.