The Hunga Tonga-Hunga Haapai eruption

The devastating Hunga Tonga-Hunga Haapai eruption in January 2022 produced the tallest volcanic plume ever recorded, a brand new evaluation by Oxford College researchers has discovered. The ash cloud from the 57 km (35 mi) eruption can also be the primary to be seen within the mesosphere, a layer of the environment extra generally related to capturing stars.

Utilizing satellite tv for pc photos, researchers have confirmed that the January 2022 eruption of the Hunga Tonga-Hunga Haapai volcano produced the very best plume ever recorded. The huge eruption can also be the primary instantly noticed to have penetrated the mesospheric layer of the environment. Outcomes from a workforce of scientists[{” attribute=””>University of Oxford’s Department of Physics and RAL Space, were published on November 3 in the journal Science.

On January 15, 2022, Hunga Tonga–Hunga Haʻapai, a submarine volcano in the Tongan archipelago in the southern Pacific Ocean, violently erupted. The explosion was one of the most powerful ever observed, sending shock waves around the world and triggering devastating tsunamis that left thousands homeless. A towering column of ash and water was ejected into the atmosphere – but until now, scientists lacked an accurate way to measure just how tall this was.

Normally, the height of a volcanic plume can be estimated by measuring the temperature recorded at the top by infrared-based satellites and comparing this to a reference vertical temperature profile. This is because in the troposphere (the first and lowest layer of the Earth’s atmosphere), temperature decreases with height. But if the eruption is so large that the plume penetrates into the next layer of the atmosphere (the stratosphere), this method becomes ambiguous because the temperature begins to increase again with height (due to the ozone layer absorbing solar ultraviolet radiation).

A zoomed-in view of the Hunga Tonga-Hunga Haapai eruption on January 15, 2022, as recorded by NOAA’s GOES-17 climate satellite tv for pc. Credit score: Simon Proud and Simeon Schmaus / Uni Oxford, RALSpace NCEO / NOAA

To beat this drawback, the researchers used a brand new technique based mostly on the phenomenon referred to as “parallax impact”. That is the obvious distinction within the place of an object when considered from a number of viewpoints. You possibly can see this for your self by closing your proper eye and holding out one hand with a thumbs up. For those who then swap your eyes in order that your left is closed and your proper is open, your thumb will seem to float barely into the background. By measuring this obvious change in place and mixing it with the identified distance between your eyes, you’ll be able to calculate your thumb distance.

The situation of the Tonga volcano is roofed by three geostationary climate satellites, so the researchers have been in a position to apply the parallax impact to the aerial photos taken. Crucially, throughout the eruption itself, satellites recorded photos each 10 minutes, permitting the speedy modifications within the plume’s trajectory to be documented.

The outcomes confirmed that the plume reached an altitude of 57 kilometers (35 miles) at its peak. That is considerably greater than the earlier document holders: the 1991 eruption of Mount Pinatubo within the Philippines (40 km / 25 miles on the highest level), and the 1982 eruption of El Chichon in Mexico (31 km / 19 miles). It additionally makes the plume the primary observational proof {that a} volcanic eruption injects materials into the stratosphere and instantly into the mesosphere, beginning about 50 km (31 mi) above Earth’s floor.

“That is the primary time now we have ever recorded a volcanic plume reaching the mesosphere. Krakatau within the 1800s might have accomplished it too, however we did not see it in sufficient element to substantiate,” mentioned Dr Simon Proud, senior scientist on the Nationwide Earth Remark Heart on the College of Oxford and senior scientist on the Science and Know-how Establishments Council. RAL House facility.

“It is a unprecedented consequence as a result of we have by no means seen a cloud this excessive earlier than,” Proud added. “Moreover, the power to estimate altitude the best way we did (utilizing the parallax technique) is barely attainable now that now we have good satellite tv for pc protection. That would not have been attainable a decade in the past.”

Now Oxford researchers intend to construct an automatic system to calculate the heights of volcanic plumes utilizing the parallax technique.

Dr Andrew Prata, co-author of the Division of Atmospheric, Oceanic and Planetary Physics, added: “We might additionally like to use this system to different eruptions and develop a set of plume heights that can be utilized by volcanologists and atmospheric scientists. to mannequin the dispersion of volcanic ash within the environment. Additional scientific questions we want to perceive are: Why did the Tonga pole get so excessive? What would be the local weather influence of this eruption? And what precisely was the feather fabricated from?’

Reference. “Hunga Tonga-Hunga Haapai Volcano’s January 2022 Eruption Reaches the Mesosphere” Simon R. Prudy, Andrew T. By Prata and Simeon Schmaus November 3, 2022 Science.
DOI: 10.1126/science.abo4076

Along with the College of Oxford, the Rutherford Appleton Laboratory and the Harwell Nationwide Heart for Earth Remark and the Munich College of Utilized Sciences additionally participated within the analysis.

The three satellites used to detect and assess the eruption are GOES-17 (USA), Himawari-8 (Japan), and GeoKompSat-2A (Korea). The open entry knowledge was developed by the UK’s Jasmin Supercomputer on the Science and Know-how Establishments Council’s Rutherford Appleton Laboratory.