Re: What is the determining factor in thunder decibel levels?

I don't think there is a single determining factor in determining thunder volume. Like many natural phenomena, it's a complex interaction of many processes, including:

1. Energy Released Lightning strikes which dump more electrical energy into the atmosphere will generate more sound energy.
2. Distance Thunder sounds quieter when it's farther away, but there's no simple formula for how it does so, due to the factors listed below.
3. Geometry The shape of a lightning bolt can change the loudness of its thunder in different directions. For example, suppose a lightning strike arched from 1/2 mile directly over your head to 1/2 mile off to your side. (Lucky you!) All the sound from the whole length of the strike would reach you at the same time, resulting in an unusually loud thunderclap.
4. Reflectors A large building, hillside, or other large object can reflect sound toward you or block it from you.
5. Refractors The speed of sound changes with temperature: warmer or cooler parcels of air can bend sound waves toward or away from you. Changes in windspeed can bend and twist sound waves.

Computing the loudness of a thunderclap would be a very, very difficult problem to solve in the complex real world, but the above processes are probably the important ones which affect it.

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