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1. How did the volcanic eruption affect Earth's atmosphere?
2. What kind of weather effects could occur due to this eruption?

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Volcanologists and meteorologists alike watched in awe as the Hunga Tonga-Hunga Haʻapai volcano erupted near the South Pacific country of Tonga last week.

The once-in-a-lifetime eruption was devastating for Tonga and spread a tsunami to the United States' Pacific coast, Japan and Peru, but scientists were also able to admire the power of this eruption unlike ever before.

Here are a few ways that meteorologists were able to watch this eruption through the lens of the atmosphere:

1. The Ash Plume Reached the Mesosphere

The eruption's initial blast caused the plume of ash and vapor to climb some 55 kilometers, or more than 34 miles, high into the atmosphere.

Typically, air stops rising far below 60,000 feet, where air temperatures begin to warm and air loses its buoyancy. In this case, the upward force of the explosion combined with the heat of the plume allowed the vapor to rise to 180,000 feet.

The top of the plume was a relatively narrow column of volcanic material, likely located directly over the volcano. This feature, which somewhat resembles the top of a smashed witch's hat, is called an overshooting top in meteorology.

Below this overshooting top was a very wide canopy of clouds in the stratosphere, denoted by the umbrella marker in the tweet above.

And still below this, in the typical weather portion of the Earth's atmosphere, a more milky vapor plume is shown in the troposphere.

This enormous plume cloud was very similar to the structure of a thunderstorm - on steroids.

A severe thunderstorm's overshooting top can tower over 60,000 feet, a mere 120,000 feet shorter than the volcanic plume.

2. Pressure Wave Circled the Globe Several Times

When something this intrusive enters three different layers of the atmosphere, you can be sure there will be ripples around the world.

Meteorologists and weather enthusiasts alike watched their local and home weather stations for several days earlier this week as pressure readings from their barometers jumped up and down by a couple of millibars at least three times.

The shockwave was emitted from the South Pacific in circular rings immediately after the eruption.

In the U.S., this shockwave first moved eastward from the Southwest toward the Northeast on Jan. 15. Then, the wave that was emitted westward from Tonga reached the eastern U.S. during the early-morning hours of Jan. 16.

The westward-propagating portion of the pressure wave reached the U.S., circumnavigating the globe at nearly 700 mph, that following night. Initial waves traveled faster than the speed of sound, which caused sonic booms heard as far away as Alaska, nearly 6,000 miles away.

This sort of pressure wave is not unprecedented. Krakatoa's 1883 mega eruption caused a pressure wave to circumnavigate the globe at least three times, passing over some barometers as many as seven times.

3. Temperature Ripples Crossed the Pacific

With the pressure wave crossing the Pacific Ocean, temperature fluctuations were also measured by the thermal infrared sounder onboard the Metop satellite in the upper troposphere or lower stratosphere.

In the tweet below, the satellite measured these changes on Jan. 15, with temporary warming sensed likely as the wave descended into the atmosphere and causing the air to warm by compression.

Waves of blue are seen where the air was pushed upward and cooled by expansion.

These temperature changes were not widespread and were not measured at any land-based site.

4. Extreme Lightning Discharge

Lightning is a common sight with volcanic eruptions, but Hunga Tonga put on one amazing show when it erupted.

The plume produced nearly 400,000 lightning strikes on the Vaisala lightning tracker within a few hours of the eruption. That's over 5,000 lightning events every minute, according to Vaisala's Chris Vagasky.

Lightning occurs around volcanoes because of the natural friction between particles of ash and particles of water vapor at different altitudes and the electrical charges that result from the turbulence within an eruption.

The 2018 Anak Krakatoa eruption caused 337,000 lightning events over a week, according to Vagasky; Iceland's Eyjafjallajökull eruption in 2010 was also a prolific lightning producer.

You can see ripples of lightning as the volcanic plume pushed higher into the stratosphere and mesosphere, which is a result of gravity waves emanating from the eruption. As waves passed, their upward motion caused upticks in lightning, and the downward motion caused a relative lull in lightning activity.
(MORE: Detailed Explanation of Volcanic Lightning)
5. Clouds Formed Over Hawaii

Along with the movement of air radiating across the Pacific, the observatories in Hawaii also caught clouds radiating across the Pacific shortly after the eruption.

These thin clouds were likely caused by short-lived upward motions within the shockwave as it moved laterally through the atmosphere. The other clouds in the video suggest that there was at least some moisture in the atmosphere over Hawaii at the time. This moisture helped these waves become visible.

In contrast, some reports suggest that the blast helped dissipate fog in and around the Seattle area.

6. Meteotsunami Measured Near Puerto Rico

Perhaps one of the crazier results of the eruption was that it caused a push of water as far away as Puerto Rico.

This wasn't the same tsunami that spread out across the Pacific, but rather, it was caused by the pressure wave mentioned above.

What seems to have happened was that the pressure wave helped push water in the Mona Passage, located west of Puerto Rico, eastward toward the island. This is called a meteotsunami.

Meteotsunamis are becoming more common due to better instrumentation and more scientists becoming aware of such phenomena. They are most common ahead of strong cold fronts in the Great Lakes and Gulf of Mexico but have also been seen on the East Coast.

Will This Eruption Affect the Climate?

It appears so far that the answer is no.
The Weather Company's primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.
Sulfur dioxide that is released from volcanic eruptions like this one can have a cooling effect on Earth, but Hunga Tonga released a relatively minuscule amount of SO2 compared to other climate-changing eruptions.

Other mega eruptions like Pinatubo in 1991 released enough sulfur dioxide to cool the Earth's surface for three years, while some eruptions, including Krakatoa, had even bigger impacts.

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Six Ways the Tonga Volcano Affected the Atmosphere | The Weather Channel - Articles from The Weather Channel | weather.com

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Volcanologists and meteorologists alike watched in awe as the Hunga Tonga-Hunga Haʻapai volcano erupted near the South Pacific country of Tonga last week. The once-in-a-lifetime eruption was devastating for Tonga and spread a tsunami to the United States' Pacific coast, Japan and Peru, but scientists were also able to admire the power of this eruption unlike ever before.

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1. Why do you think the volcanic explosion triggered a lightning storm?
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Judy, scientists say the explosion revealed some of the mysteries of underwater volcanoes. It produced a tsunami that was felt on the coasts of Japan and the United States, 5,000 miles away, and triggered an oil spill in Peru. It set off a lightning storm that lasted seven hours and had 400,000 strikes. It was heard as far away as Alaska.

But for all the ways it made itself felt around the world, its damage was relatively confined. Tonga bore the brunt of the volcano's fury, blanketed with ash that is now contaminating its water supply.

Michael Poland is a research geophysicist with the U.S. Geological Survey's Cascades Volcano Observatory in Vancouver, Washington.

Mr. Poland, thanks so much for joining us. As we talk about, it was so dramatic, this event, that huge plume that was visible from space, the tsunami, the atmospheric shockwave which rippled around the globe, but you say that the data actually showed this was a relatively small eruption.

Explain that.

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The science behind the Tonga volcanic eruption, tsunami

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The first satellite images of the Pacific nation of Tonga after Saturday's volcanic eruption emerged Tuesday. The photos show the islands coated in ash. Despite the violent explosion, the Tongan government has reported just three deaths. The status of two smaller islands in its chain is still unknown.

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WELLINGTON, New Zealand (AP) - People around the world looked on in awe at the spectacular satellite images of an undersea volcano erupting in a giant mushroom cloud in the Pacific. Many wondered why the blast was so big, how the resulting tsunami traveled so far, and what will happen next. New Zealand scientists Shane Cronin, a volcanology professor at the University of Auckland, and Emily Lane, a tsunami expert at the National Institute of Water and Atmospheric Research, help explain.

EXPLOSIVE BUT BRIEF

The eruption on Saturday was incredibly explosive but also relatively brief. The plume rose into the air more than 30 kilometers (19 miles) but the eruption lasted only about 10 minutes, unlike some big eruptions that can continue for hours. Cronin said the power of the eruption of the Hunga Tonga Hunga Ha'apai volcano ranks among the world's biggest over the past 30 years, and the height of the plume of ash, steam and gas was comparable with the huge 1991 eruption of Mount Pinatubo in the Philippines, which killed several hundred people.
WATCH: The science behind the Tonga volcanic eruption, tsunami
WHY SO BIG?

The magma inside the volcano was under enormous pressure and had gasses trapped within it. A fracture in the rock likely induced a sudden drop in pressure, allowing the gas to expand and blast the magma apart. Cronin said the crater was sitting about 200 meters (650 feet) below the sea surface, a kind of Goldilocks depth for a big explosion in which seawater pours into the volcano and turns instantly into steam, adding to the rapid expansion and energy of the explosion. Any deeper and the extra pressure of the water would have helped contain the eruption.

FARFLUNG TSUNAMI

Many scientists were surprised that a single eruption could produce a Pacific-wide tsunami of about 1 meter (3 feet) that smashed boats in New Zealand and caused an oil spill and two drownings in Peru. Lane said that oceanwide tsunamis are usually triggered by earthquakes that extend across huge areas rather than from a single volcano, essentially a tiny dot in the ocean. She said other factors may have been at play, such as an underwater flank of the volcano collapsing and displacing water. She said one interesting theory is that the shock wave, or sonic boom, from the volcano that traveled twice around the world may have pumped more power into the tsunami waves.

TONGA MAINLY SPARED

Another mystery is why the tsunami wasn't bigger and more destructive in Tonga, which sits almost on top of the volcano.

"That's the million dollar question," Cronin said. "Looking at the images so far, the level of devastation is less than I was fearing."

Authorities by Wednesday had confirmed three deaths in Tonga, with concerns remaining about people on some of the hard-hit smaller islands. Dozens of homes were destroyed.

Lane said that Tongans at least got some warning, both from the increased activity at the volcano the day before the eruption and from the incredibly loud bang when it erupted but before the tsunami hit, allowing many to scramble to higher ground. She said reefs, lagoons and other natural features may also have protected parts of Tonga, while amplifying the waves in certain areas.
READ MORE: Three dead in volcano eruption aftermath, but Tonga appears to avoid major destruction
FALLING ASH

The ash that has coated Tonga is acidic but not poisonous, Cronin said. Indeed, he has been advising Pacific responders that people may still be able to drink from their rainwater supplies even if some ash has fallen in, which will make the water more acidic and salty. He said it was a question of applying the taste test and if water became scarce, it would be better drinking ash-tainted water than stagnant water that might be contaminated with bacteria. New Zealand and other nations are trying to get water and other supplies to Tonga as quickly as possible. Cronin said all of Tonga's soil comes from volcanic ash and the latest dump of ash would quickly wash into the ground and make the nation more fertile.

NO GLOBAL COOLING

Huge volcanic eruptions can sometimes cause temporary global cooling as sulfur dioxide is pumped into the stratosphere. But in the case of the Tonga eruption, initial satellite measurements indicated the amount of sulfur dioxide released would only have a tiny effect of perhaps 0.01 degree Celsius (0.02 Fahrenheit) global average cooling, said Alan Robock, a professor at Rutgers University.

WHAT'S NEXT

Cronin envisions two main scenarios for the volcano. The first is that it has exhausted itself for now and will go quiet for the next 10 to 20 years as magma slowly returns. A second scenario is that new magma rises up quickly to replace that which exploded, in which case there might be ongoing eruptions. But he believes the cracks and rifts caused by Saturday's big explosion will allow more gas to escape, and subsequent eruptions won't be as big, at least for now. Both Cronin and Lane agree there needs to be much better monitoring of the volcano - and others in Tonga - to help better predict future events.
Associated Press Science Writer Seth Borenstein in Kensington, Maryland, contributed to this report.

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Experts explain why Tonga eruption was so big

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WELLINGTON, New Zealand (AP) - People around the world looked on in awe at the spectacular satellite images of an undersea volcano erupting in a giant mushroom cloud in the Pacific. Many wondered why the blast was so big, how the resulting tsunami traveled so far, and what will happen next.

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1. Why are scientists looking at Tonga to explain events on Mars?

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Using Earth to understand how water may have affected volcanoes on Mars

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1. How was Tonga created?
2. What event occurred in 2015?
3. What part of the world is Tonga located?
4. What event occurred on Jan. 15, 2022?

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When a volcano in the South Pacific Kingdom of Tonga began erupting in late-December 2021 and then violently exploded in mid-January 2022, NASA scientist Jim Garvin and colleagues were unusually well positioned to study the events. Ever since new land rose above the water surface in 2015 and joined two existing islands, Garvin and an international team of researchers have been monitoring changes there. The team used a combination of satellite observations and surface-based geophysical surveys to track the evolution of the rapidly changing piece of Earth.

The digital elevation maps above and below show the dramatic changes at Hunga Tonga-Hunga Ha'apai, the uppermost part of a large underwater volcano. It rises 1.8 kilometers (1.1 miles) from the seafloor, stretches 20 kilometers (12 miles) across, and is topped by a submarine caldera 5 kilometers in diameter. The island is part of the rim of the Hunga Caldera and was the only part of the edifice that stood above water.

Now all of the new land is gone, along with large chunks of the two older islands.

"This is a preliminary estimate, but we think the amount of energy released by the eruption was equivalent to somewhere between 4 to 18 megatons of TNT," said Garvin, chief scientist at NASA's Goddard Space Flight Center. "That number is based on how much was removed, how resistant the rock was, and how high the eruption cloud was blown into the atmosphere at a range of velocities." The blast released hundreds of times the equivalent mechanical energy of the Hiroshima nuclear explosion. For comparison, scientists estimate Mount St. Helens exploded in 1980 with 24 megatons and Krakatoa burst in 1883 with 200 megatons of energy.

Garvin and NASA colleague Dan Slayback worked with several researchers to develop detailed maps of Hunga Tonga-Hunga Ha'apai above and below the water line. They used high-resolution radar from the Canadian Space Agency's RADARSAT Constellation Mission, optical observations from the commercial satellite company Maxar, and altimetry from NASA's ICESat-2 mission. They also used sonar-based bathymetry data collected by the Schmidt Ocean Institute, in partnership with NASA and Columbia University.

For the past six years, researchers from NASA, Columbia, the Tongan Geological Service, and the Sea Education Association worked together to determine how the young terrain was eroding due to the ongoing churn of waves and occasional battering by tropical cyclones. They also noted how wildlife-various types of shrubs, grasses, insects, and birds-had moved from the lush ecosystems of Hunga Tonga and Hunga Ha'apai and colonized the more barren landscapes of the newer land.

Things changed dramatically in January. For the first few weeks of 2022, the volcanic activity seemed typical enough, with intermittent, small explosions of tephra, ash, steam, and other volcanic gases as magma and seawater interacted at a vent near the middle of the island. The ongoing Surtseyan eruptions were reshaping the landscape and enlarging the island by adding new deposits of ash and tuff to the growing volcanic cone.

"By early January, our data showed the island had expanded by about 60 percent compared to before the December activity started," said Garvin. "The whole island had been completely covered by a tenth of cubic kilometer of new ash. All of this was pretty normal, expected behavior, and very exciting to our team."

But on January 13-14, an unusually powerful set of blasts sent ash surging into the stratosphere. Then explosions on January 15 launched material as high as 40 kilometers (25 miles) in altitude and possibly as high as 50 kilometers, blanketing nearby islands with ash and triggering destructive tsunami waves. An astronaut aboard the International Space Station took this photo of ash over the South Pacific.

Most Surtseyan style eruptions involve a relatively small amount of water coming into contact with magma. "If there's just a little water trickling into the magma, it's like water hitting a hot frying pan. You get a flash of steam and the water burns burn off quickly," explained Garvin. "What happened on the 15th was really different. We don't know why - because we don't have any seismometers on Hunga Tonga-Hunga Ha'apai - but something must have weakened the hard rock in the foundation and caused a partial collapse of the caldera's northern rim. Think of that as the bottom of the pan dropping out, allowing huge amounts of water to rush into an underground magma chamber at very high temperature."

The temperature or magma usually exceeds 1000 degrees Celsius; seawater is closer to 20°C. The mixing of the two can be incredibly explosive, particularly in the confined space of a magma chamber. "This was not your standard Surtseyan eruption because of the large amount of water that had to be involved," said Garvin. "In fact, some of my colleagues in volcanology think this type of event deserves its own designation. For now, we're unofficially calling it an 'ultra Surtseyan' eruption."

For a geologist like Garvin, watching the birth and evolution of a "Surtseyan island" like this is fascinating, partly because there have not been many other modern examples. Aside from Surtsey -which formed near Iceland in 1963 to 1967 and still exists more than a half-century later-most new Surtseyan islands get eroded away within a few months or years.

What also interests Garvin about these islands is what they may teach us about Mars. "Small volcanic islands, freshly made, evolving rapidly, are windows in the role of surface waters on Mars and how they may have affected similar small volcanic landforms," he said. "We actually see fields of similar-looking features on Mars in several regions."
NASA Earth Observatory images by Joshua Stevens, using elevation data courtesy of Dan Slayback/NASA/GSFC. Astronaut photograph ISS066-E-117965 was acquired on January 16, 2022, with a Nikon D5 digital camera using a focal length of 50 millimeters. NASA ground photo by Dan Slayback. Story by Adam Voiland.

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Dramatic Changes at Hunga Tonga-Hunga Ha'apai

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When a volcano in the South Pacific Kingdom of Tonga began erupting in late-December 2021 and then violently exploded in mid-January 2022, NASA scientist Jim Garvin and colleagues were unusually well positioned to study the events. Ever since new land rose above the water surface in 2015 and joined two existing islands, Garvin and an international team of researchers have been monitoring changes there.