In the hustle and bustle of a major metro area like Denver, there are rarely times that the whole world seems to go quiet.
But one of those preciously few moments of relative urban silence usually comes after a snowstorm. Of course, part of the perceived quiet can be attributed to a big reduction in traffic and pedestrians after a fresh snowfall. But there’s also a real science behind the silence.
When snow falls, it absorbs sound waves. When snow falls, there are big gaps of space left in between snowflakes, particularly in a fluffier and colder snow event.
But with snow, flakes gently pile on top of each other, leaving tiny gaps of space in between them (as opposed to water molecules, which tightly stick together). While sound waves can often find their way into a space between bits of freshly-accumulated snow, they often have a difficult time getting back out of those small gaps.
Sound waves also travel slower in colder weather, slowing down their forward speed and further muffling noise.
says that snow absorbs about 60% of sound.
Days after the snow initially falls, though, the ice crystals compact and consolidate. That quickly reduces the amount of space that sound waves can travel into, and sound returns to normal. Also, the melting and re-freezing of ice can reflect (echo) sound waves.
That, in short, is what scientifically creates the silence after a fresh snowfall, and why it tends to happen right after a recent snowfall.
