I am absolutely convinced that fog deadens sound. But to this layman’s intuition that makes it seem as if a cloud would absorb sound, not reflect or refract it and thus make it less noisy or at least have no effect.
If the clouds are associated with a thermocline, does anyone know if/how that affects sound? I recall this coming up in some submarine warfare adventure fiction, so clearly my sources are . . . sound.
Interesting to follow this debate - I assumed it was an absolute yes based on my own anecdotal experience.
I once lived in a high-rise in Toronto several kilometres (miles) from the train tracks that ran along the lakeshore (by the CN tower). There were many blocks of skyscrapers between us and the tracks. At night with less absent noise and with low cloud cover we could very clearly hear the trains slowly clunking along the tracks and the sound as they changed up the cars. It was like they were outside our window.
ISTM the only possible way the sound would have made its way to us was via reflection (or refraction?) off the low cloud cover above.
This doesn’t specifically mention thermoclines, but I’m assuming you get one when there’s an inversion?
Sorry, I should have clarified; yes, an inversion is in fact a thermocline.
The board sofwtware crops off of the quoted material from the Wikipedia right before it mentions the relevance to highway noise pollution.
Thanks. That was probably obvious but I’m very much not up to speed on atmospheres or sounds.
I know light waves, not sound, but waves is waves*
When you have a sudden change in properties, say a thermocline or surface of a lens, three things can happen. Some energy is reflected, some is absorbed (usually as heat), and some is transmitted. Transmitted includes refraction. So a thermocline is temperature boundary, the bottom of a clod is a density/humidity boundary, so they could reflect sound.
Inside a cloud or fog, you still have some reflection, but there would be a lot more absorption from all the extra water droplets particles to interact with. So sound from somewhere else in the cloud would be muffled. Hearing via refraction, I suspect, would be a lot more difficult & complicated scenario, but I don’t really know.
- Yeah, transverse vs longitudinal, but similar enough to give insight.