The massive plume of Tonga’s volcano has reached the mesosphere – 38 miles into the atmosphere

The train from Hunga Tonga-Hunga Ha’apai behaved like a mega-thunderstorm that rose 58 kilometers (38 miles) into the atmosphere.

If en an eruption of an underwater volcano occurred near a small uninhabited island c Hunga Tonga-Hunga Haapai in January 2022, two weather satellites were in a unique location to observe the height and width of the plume. Together they captured what is probably the highest plume in the satellite record.

Scientists in[{” attribute=””>NASA’s Langley Research Center analyzed data from NOAA’s Geostationary Operational Environmental Satellite 17 (GOES-17) and the Japanese Aerospace Exploration Agency’s (JAXA) Himawari-8, which both operate in geostationary orbit and carry very similar imaging instruments. The team calculated that the plume from the January 15 volcanic eruption rose to 58 kilometers (36 miles) at its highest point. Gas, steam, and ash from the volcano reached the mesosphere, the third layer of the atmosphere.

Prior to the Tonga eruption, the largest known volcanic plume in the satellite era came from Mount Pinatubo, which spewed ash and aerosols up to 35 kilometers (22 miles) into the air above the Philippines in 1991. The Tonga plume was 1.5 times the height of the Pinatubo plume.

“The intensity of this event far exceeds that of any storm cloud I have ever studied,” said Kristopher Bedka, an atmospheric scientist at NASA Langley who specializes in studying extreme storms. “We are fortunate that it was viewed so well by our latest generation of geostationary satellites and we can use this data in innovative ways to document its evolution.”

The animation above shows a stereo view of Tonga’s eruption plume as it rose, evolved and dissipated for 13 hours on January 15, 2022. The animation was based on infrared observations obtained every 10 minutes by GOES-17 and Himawari- 8. According to these observations, the initial explosion quickly rose from the ocean surface to 58 kilometers in about 30 minutes. Shortly thereafter, the secondary pulse rose above 50 kilometers (31 miles) and then split into three parts.

Typically, atmospheric scientists calculate cloud height using infrared instruments to measure cloud temperature and then comparing it to a temperature and altitude model. However, this method is based on the assumption that the temperature decreases at a higher altitude, which is true in the troposphere, but not necessarily in middle and upper atmosphere. Scientists needed another method to calculate height: geometry.

Hunga Tonga-Hunga Ha’apai is located in the Pacific Ocean about halfway between Himawari-8, which is in geostationary orbit at 140.7 ° east longitude, and GOES-17, in geostationary orbit at 137.2 ° west. “From two satellite angles, we were able to recreate a three-dimensional picture of the clouds,” said Konstantin Khlopenkov, a NASA scientist Langley.

Annotated stereoscopic observations of Tongan volcano

January 15, 2022

This sequence of photos from GOES-17 shows a plume at various stages on January 15th. Notice how the highest parts of the plume in the stratosphere and mesosphere cast shadows on the lower parts.

Khlopenkov and Bedko used a technique they originally developed to study strong thunderstorms that penetrate the stratosphere. Their algorithm compares simultaneous observations of the same cloud scene from two satellites and then uses stereoscopy to construct a three-dimensional profile of elevated clouds. (This is similar to how the human brain perceives things in three dimensions using two images from our eyes.) Khlopenkov then tested stereoscopic measurements using the length of the shadows that the highest plumes cast on the wide clouds of ash below. They also compared their measurements with an analysis of NASA’s GEOS-5 model to determine the local height of the stratosphere and troposphere that day.

The uppermost part of the train sublimated almost immediately due to extremely dry conditions in the mesosphere. However, an umbrella of ashes and gas stretched out stratosphere at an altitude of about 30 kilometers (20 miles), eventually covering an area of ​​157,000 square kilometers (60,000 square miles), more than the state of Georgia.

“If volcanic material rises so high into the stratosphere, where the winds are not so strong, volcanic ash, sulfur dioxide, carbon dioxide and water vapor can spread across the Earth,” said Khlopenkov. Within two weeks, the main plume of volcanic material flew around the globe, as observed by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), as well as Ozone Mapping and Profiler Suite on Suomi-NPP.

The aerosols from the plume remain in the stratosphere for almost a month after the eruption and may remain for a year or more, said athematic scientist Hassan Taha of NASA’s Goddard Space Flight Center. Volcanic emissions can potentially affect local weather and global climate. However, Taha noted that it now seems unlikely that Tonga’s plume will have significant climate effects because it was low in sulfur dioxide – a volcanic emission that causes cooling – but high in water vapor, which explains its impressive height.

“The combination of volcanic heat and the amount of superheated moisture from the ocean has made this eruption unprecedented. It was like hyperfuel for a meganowner, ”Bedka said. “The plume rose 2.5 times higher than any thunderstorm we’ve ever seen, and the eruption spawned an incredible amount of lightning. That’s what makes it important from a meteorological point of view. “

Images and videos from NASA’s Earth Observatory, taken by Joshua Stevens, using data provided by Christopher Bedk and Konstantin Khlopenkov / NASA’s Langley Research Center, and images of GOES-17 from NOAA and the National Environmental Satellite Service (NES). The story of Sophie Bates, NASA’s Earth Science News Group, with Mike Karlovich. The massive plume of Tonga’s volcano has reached the mesosphere – 38 miles into the atmosphere

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