Weather and Traffic noise?

Question

On a relitively cool summer morning in Phoenix AZ ( a rare and precious thing) it was noticed that traffic noise was particularly loud....It was hypothesized that the reason that the noise was louder was because the cool morning made tires noisier. Is that person even a little correct? ( lower temps mean that tires have denser air making them "flattter" What do you say?

Answer 1

Since you mentioned a "relatively cool summer morning" I suspect that the nocturnal inversion was trapping sound beneath it.

Was it noticed that the noise diminished as the morning progressed? If so, then this is the answer.

Nocturnal Inversion
Used interchangably with Radiational Inversion; a temperature inversion that develops during the night as a result of radiational cooling of the surface. Because the immediate surface (lower Boundary Layer) cools much more rapidly during radiational cooling conditions than the air just above (upper Boundary Layer), a temperature inversion can be created overnight, but typically erodes quickly after sunrise.

Answer 2

The whole tire thing doesn't have to do with denser air (although that plays a part) but denser tires. The density of tires changes dramatically with temperature. Just as shoes with a dense sole( like dress shoes) makes a louder noise than those with soft soles (like running shoes), so do tires. Also sound travels better in denser mediums than less dense mediums so you perceive the noise a lot better. To prove this take a water-proof watch and have someone make it beep at one end of a pool. compare the distance you can hear it inside the pool to outside the pool.

Answer 3

I see a couple of good theories.

Here's mine. The cool air is due to a low level cloud layer, offering a bit of shade from direct sunlight. This admittedly thin cloud layer reflects some traffic sound back down at you, so that the noise level is raised.

Ooh! I just read the temperature inversion answer. I like that one better. Just substitute my avatar for his.

Answer 4

Cooler air is denser, so it can make noise louder and more distinct. But I don't know if the air was so dense that the human ear could pick up the subtlety.

Answer 5

as a results of fact lots of the flaws that mute sounds have long previous away, like tree leaves and grass. whilst snow mutes sound whether it extremely is comfortable, whether it extremely is glazed, it reflects them. additionally lacking are the white noise components, at the same time with rustling of leaves, birds, which tend to mask different sounds.

Answer 6

The more moisture in the air, the more sound is muffled. If it is dry, then sound travels further and sounds louder.