Check out why you can hear things in the distance on cold mornings.
JACKSONVILLE, Fla – Who would like to go out with me for a bit? Because when we start into December, we had a couple of pretty cool mornings on the First Coast.
One thing that you should know about Jacksonville is that there are many airports. A couple of people wrote to me today asking why the military or airplane in general is so loud ?!
Overall, the flights in the region were not unusual. So what was going on? When we have cold mornings under high pressure here in Jacksonville, we often get something called an inversion. Typically, temperatures drop with altitude the higher you rise, but with an inversion it’s backwards and colder near the surface than in the air.
For example, the morning temperature on Wednesday was almost freezing, but rose up to 10 degrees (50 degrees F) about 1,000 feet above the ground. These trapped sound waves below 1,000 feet and thus the sound from each aircraft was transmitted over a greater distance.
This is because sound moves faster in warmer air than in cold air. So if it moves into the warmer air in the early morning, it will break back to the surface, which will keep the loud noises of the nozzles closer to the surface for a longer period of time.
This is what we refer to as a “channel” in meteorology. In fact, it can even become airborne if you have an area of warm air, then cold air, then warm air. The clay is trapped in this cold layer.
This is the same reason why, on cold mornings, wherever you are in the world, you can sometimes hear sounds in the distance that you would not otherwise hear. It’s a fun weather fact that you can find ours now on a cool winter morning.