Tonga Volcanic Eruption Blasted an Enormous Plume of Water Vapor Into the Atmosphere

NASA scientists say the intrusion could warm the Earth’s surface

A landmass with white smoke coming out of it
The Hunga Tonga-Hunga Ha'apai volcano releases gas on December 24, 2021, before the eruption on January 14. Photo by Maxar via Getty Images

The Hunga Tonga-Hunga Ha’apai (HT-HH) volcano eruption in Tonga last January propelled a record-breaking amount of water vapor into the Earth’s stratosphere—enough to fill more than 58,000 Olympic-size swimming pools, according to research from NASA. 

“We’ve never seen anything like it,” Luis Millán, an atmospheric scientist at NASA’s Jet Propulsion Laboratory in Southern California, says in a statement. “We had to carefully inspect all the measurements in the plume to make sure they were trustworthy.” 

In a paper published in Geophysical Research Letters, scientists analyzed data from the Microwave Limb Sounder, an instrument that measures gasses like water vapor and ozone from NASA’s Aura satellite, per the statement. They found that the undersea volcano’s plume reached altitudes up to about 35 miles, a “record in the satellite era.” The plume released 146 teragrams of water vapor into the stratosphere, which is equivalent to about 10 percent of the total water already in that layer of the atmosphere.

While previous volcanic blasts have caused a temporary cooling effect on the Earth because of ash and dust that reflect sunlight back into space, this one will likely raise temperatures because of water vapor’s heat-trapping properties, per the study. 

“This is just a temporary warming, and then it will go back to whatever it was supposed to go back to,” Millán, the lead author on the study, tells the Washington Post’s Kasha Patel. “It’s not going to exacerbate climate change.”

The January eruption in Tonga was the world's largest in the 21st century, and possibly the most powerful since Krakatoa in 1883, per CNN’s Katie Hunt. The explosion rained ash down on Tonga and triggered a tsunami, which damaged more than 100 homes and killed three people. 

Scientists say the explosion was more powerful than hundreds of atomic bombs and produced a shockwave that circled the Earth for days. The resulting water vapor may remain in the atmosphere for five to 10 years, and the warming effect will likely begin in three years, Millán tells the Post

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