Elusive atmospheric wave detected during Tonga volcanic eruption
Satellite image of Tonga volcanic eruption, 2022. Credit: NASA Worldview, NOAA / NESDIS / STAR

The atmospheric wave that has been missing for the past 85 years was triggered by the eruption of the Hunga Tonga–Hunga Haapai volcano. State-of-the-art observational data and computer simulations were used by researchers from the University of Hawaii at Mnoa.

The study was published in a scientific journal.

The most powerful explosion the world has experienced since the famous 1883 eruption of Mt. Hood was caused by the eruption in the South Pacific. There is a town in Indonesia. Pressure waves in the atmosphere are caused by the rapid release of energy.

Thousands of miles away, an isolated wave front traveled at more than 650 miles per hour as it spread outward from the eruption. The air pressure changes associated with the initial wave front were visible on thousands of records.

Kevin Hamilton, a professor of atmospheric sciences at the UH Mnoa School of Ocean and Earth Science and Technology, said that a physical theory for the wave was developed by an English scientist.

The motions are called Lamb waves. A second wave solution with a slower horizontal speed was suggested by Chaim Pekeris in 1937. After the Krakatau eruption, Pekeris attempted to find evidence for his slower wave in the pressure observations.


It was possible to identify the wave successfully.

Scientists used a wide range of tools, including satellite observations, computer simulations, and dense networks of air pressure observations, to identify the Pekeris wave in the atmosphere.

Shingo Watanabe is the deputy director of the Japan Agency for Marine- Earth Science and Technology's Research Center for Environmental Modeling.

The properties of the slower wave front were similar to those predicted by Pekeris almost a century ago.

More information: Shingo Watanabe et al, First Detection of the Pekeris Internal Global Atmospheric Resonance: Evidence from the 2022 Tonga Eruption and from Global Reanalysis Data, Journal of the Atmospheric Sciences (2022). DOI: 10.1175/JAS-D-22-0078.1