Source: Geophysical Research Letters.

Whenever we see advances in innovative illustration to better our understanding of phenomena, natural or otherwise, we note it here. Atmospheric pressure is something most of us have heard countless times, but not necessarily stopped to think what it is. Among other things, it is important. Also, it is understandable. If you have a couple minutes, watch this accessible animation of a natural phenomenon that does not get enough attention, and read the accompanying text:

‘It’s Super Spectacular.’ See How the Tonga Volcano Unleashed a Once-in-a-Century Shockwave.

By Aatish Bhatia and Henry Fountain

Produced by Aatish Bhatia and Sean Catangui

As shown in this visualization, based on a simulation created by Ángel Amores, a physical oceanographer at the Mediterranean Institute for Advanced Studies in Majorca, Spain, the shockwave took about 36 hours to circumnavigate the globe, spreading out in concentric rings from the volcano known as Hunga Tonga-Hunga Haʻapai and traveling at the speed of sound. The simulation was published in the journal Geophysical Research Letters in March.

Dr. Amores was checking data from local weather stations from home when he first saw the signature of the wave. Local instruments showed sudden pressure changes when the shockwave made its first pass over Majorca, about 15 hours after the eruption.

“Then I was waiting and I said, OK, it should take like 36 hours to come back,” he said. “And then it passed again.” After another 36 hours it passed a third time.

“This is the first time that I see something like that,” he said.

“It’s super spectacular,” Peter W. Brown, a physicist at the University of Western Ontario, said of the shockwave, which traveled around the world several times at the speed of sound. “Everybody who studies atmospheric waves are all quite, I would say, awe-struck.”

In Japan, the company Weathernews maintains a network of thousands of low-cost weather sensors that collect data every minute. Many of their sensors detected nearly simultaneous spikes in air pressure as the shockwave passed: …

Read the whole article here.