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Joint Base McGuire-Dix-Lakehurst conducting mortar and howitzer tests; loud booms heard across NJ

Digital Brief: March 23, 2024
Digital Brief: March 23, 2024 03:47

WRIGHTSTOWN, N.J. (CBS) -- There were no complaints about any rocket's red glare, but plenty of New Jerseyans heard the bombs bursting in air Friday.

Users on social media reported loud booming noises late into Friday night, and high-firepower testing over at Joint Base McGuire-Dix-Lakehurst is the likely source of the sound.

The base was scheduled to test mortars, howitzers and cratering charges on Friday - part of a "high noise" period marked on the base's "noise calendar." (You can check that out over on their Facebook page.)

March 2024 Noise Calendar

Posted by Joint Base McGuire-Dix-Lakehurst on Tuesday, February 27, 2024

"This is the loudest I've heard since moving here," one resident wrote in the comments on the post Friday.

Another wrote: "Really hearing/feeling it today! Let freedom ring!"

Some even said their windows were shaking from the force of the blasts, and comments timestamped as late as 11:45 p.m. mentioned residents were still hearing and feeling the noise.

There were also controlled burns in the area and the weather conditions caused smoke to sink over areas in Mercer County, Robbinsville Mayor Dave Fried explained on Facebook.

There was a large control burn at Fort Dix. With the weather change, it caused the smoke to drift and lay low in Robbinsville, Hamilton, and Bordentown.

Posted by Dave Fried on Friday, March 22, 2024

What are mortars, howitzers and cratering charges?

We want to give you some examples of what the military equipment in question looks like. Check out the mortar cannons below in this photo of U.S. Marines and Japanese forces participating in a training exercise in Pendleton, California in 2014.

US-JPN-IRON FIST-MILITARY-IRON FIST 2014-EXERCISE
PENDLETON, California: U.S. Marine Corps and members of the Japan Ground Self-Defense Force participate in a 120mm mortar firing exercise on Feb. 6, 2014. JOE KLAMAR/AFP via Getty Images

The cratering charges are no joke, either. The U.S. Army produced a video posted on YouTube in 2013 showing a cratering charge blowing up. 

Engineers Train on Demolitions by The U.S. Army on YouTube

A howitzer is another piece of artillery that could also definitely make some noise.

Here are some Marines at New Jersey's Picatinny Arsenal firing a Howitzer:

Why were boom noises from Joint Base MDL so loud? The weather explanation

Our meteorologist Grant Gilmore explains that Friday night into Saturday morning, our region experienced something called an atmospheric inversion or a temperature inversion

To sum it up, the weather on Friday night ahead of Saturday's stormy conditions helped the air above the ground bounce or 'refract' sound waves back toward the ground.

Here's how Grant explains it:

The temperature of the air affects how sound travels through the atmosphere. Sound waves move faster in warmer air compared to relatively cooler air. Under typical circumstances the air temperature decreases with height. Sometimes different weather features can cause the air temperature to actually increase with height through different layers of the atmosphere. 

inversion-sound-refraction-1.png

When this occurs, it is called an inversion. If the air temperature near the ground is cooler than the air a little higher off the ground sound waves are refracted (bent back toward the Earth) due to their faster motion in the warmer air. Loud sounds like mortar testing, explosions, thunder, etc… will be amplified when an inversion is present, making those sounds sound louder than normal.

inversion-sound-refraction-2.png
inversion-sound-refraction-3.png
inversion-sound-refraction-4.png

This was the situation that developed Friday night into Saturday morning as the low pressure system to our south sent more warmth north in the mid-levels of the atmosphere. An inversion began to develop as temperatures near the surface started to cool and the temperature up to around 1,000 feet warmed/stayed the same temperature.

Thanks, Grant!

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