Environment

Highest volcano plume ever recorded penetrates the mesosphere

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Satellite image of the Hunga-Tonga Hunga-Ha'apai volcano around 100 minutes after its eruption
Simon Proud/Uni Oxford, RALSpace NCEO/Japan Meteorological Agency
Satellite image of the Hunga-Tonga Hunga-Ha'apai volcano around 50 minutes after its eruption
Simon Proud/Uni Oxford, RALSpace NCEO/Japan Meteorological Agency
Satellite image of the Hunga-Tonga Hunga-Ha'apai volcano around 10 minutes after its eruption
Simon Proud/Uni Oxford, RALSpace NCEO/Japan Meteorological Agency
Satellite image of the Hunga-Tonga Hunga-Ha'apai volcano around 100 minutes after its eruption
Simon Proud/Uni Oxford, RALSpace NCEO/Japan Meteorological Agency
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New analysis of a volcanic eruption off the coast of Tonga earlier this year has revealed the true extent of the massive explosion, and established its plume as the highest on record. It is also the first one to be seen stretching through lower layers of the atmosphere to enter the mesosphere, which begins at an altitude of some 50 km (31 miles).

The eruption of the Hunga-Tonga Hunga-Ha'apai to the north of Tonga on January 14 is regarded as one of the most powerful ever observed, with the event causing devastating tsunamis throughout the Pacific and shockwaves felt across the world.

Scientists at the University of Oxford have tapped into imagery from geostationary weather satellites to gain a new perspective on the event. These satellites observed the volcano from three angles and captured a sequence of images that documented the erupting plume at 10-minute intervals.

The team then used a novel measurement technique based on what’s known as the parallax effect, where a subject’s position appears to vary when viewed from different angles, (hold your thumb out in front of you and close either eye alternatively to get the idea). Measuring these apparent shifts in the subject’s position, based on the known distance between the satellites, enabled the team to calculate the distance to the plume.

Satellite image of the Hunga-Tonga Hunga-Ha'apai volcano around 50 minutes after its eruption
Simon Proud/Uni Oxford, RALSpace NCEO/Japan Meteorological Agency

The analysis showed that it reached an altitude of 57 km (35 miles) at its highest point, a great deal taller than the 40-km-high (25-mile) plume ejected from Mount Pinatubo in 1991. This also makes it the first volcanic eruption to carry material through the troposphere and stratosphere, to inject it directly into the mesosphere.

“It’s an extraordinary result as we have never seen a cloud of any type this tall before,” said lead author Dr Simon Proud. “Furthermore, the ability to estimate the height in the way we did (using the parallax method) is only possible now that we have good satellite coverage. It wouldn't have been possible a decade or so ago.”

Based on these results, the scientists now plan to develop an automated tool for calculating the heights of volcanic plumes through the parallax method.

“We’d also like to apply this technique to other eruptions and develop a dataset of plume heights that can be used by volcanologists and atmospheric scientists to model the dispersion of volcanic ash in the atmosphere,” said co-author Dr Andrew Prata. “Further science questions that we would like to understand are: Why did the Tonga plume go so high? What will be the climate impacts of this eruption? And what exactly was the plume composed of?”

The research was published in the journal Science.

Source: University of Oxford via EurekAlert

View gallery - 3 images
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6 comments
Jose Gros-Aymerich
I'd say this Tonga Volcano was the most powerful boil, pimple explosion ever. What could be the effects of this ash plume on global temperatures?
The Krakatoa eruption produced cold weather; cooling the air is just what we need right now, giving us time to implement CO2 emissions reduction technologies. Blessings +
Baldrick
This is a unique volcano as it most of the eruption pushed water in the upper atmosphere will acually increase global temperature for a few years.
G - bar
Good point on the global temperatures, but what I really want to know is how much CO2 this volcano expelled, and is it in the millions of tonnes?

Should Tonga be held responsible for the CO2 emissions?
reader
A volcanology youtube channel I subscribe to said that unlike most volcanoes, the Tonga eruption put up mostly water, so instead of cooling the planet with ash and sulfur like normal, it ended up increasing the water content of the upper atmosphere by 10% and thus heating the planet. Hence all the abnormally intense heat waves and droughts this past year. And floods. Haven't seen that data reported elsewhere yet.
VaughanPratt
1 ppm of CO2 has a mass of almost 8 billion tons of CO2. The current level is 420 ppm, or over 3 trillion tons of CO2. A few million tons isn't going to make an appreciable difference.

The mass of water vapor in the troposphere is 12.7 trillion tons. A billion more tons in the troposphere won't make much of a difference and would rain out in less than a month anyway, but in the stratosphere, conceivably it might warm a bit.
akarp
@ reader; excited that Youtube (and other internet platforms) allows for more information to be spread.