Surface-to-space atmospheric waves from Hunga Tonga-Hunga Ha'apai eruption

Area of Science:

• Atmospheric Science
• Geophysics
• Volcanology

Background:

• The Hunga Tonga-Hunga Ha'apai eruption in January 2022 was an exceptionally explosive volcanic event.
• It generated a volcanic plume reaching over 50 km in altitude.
• The eruption triggered atmospheric waves that propagated globally, an unprecedented phenomenon.

Purpose of the Study:

• To detail the global atmospheric wave response to the Hunga Tonga-Hunga Ha'apai eruption.
• To quantify the wave characteristics from the Earth's surface to the ionosphere.
• To analyze the eruption as a natural experiment for atmospheric dynamics.

Main Methods:

• Utilized a comprehensive suite of satellite and ground-based observations.
• Analyzed atmospheric wave propagation speeds and patterns.
• Quantified the contribution of latent heat release from the volcanic plume.

Main Results:

• Observed a broad spectrum of atmospheric waves, including Lamb waves and gravity waves.
• Measured Lamb wave speeds at the surface (318.2±6 m/s) and stratosphere (308±5 to 319±4 m/s).
• Recorded stratospheric gravity wave speeds between 238±3 and 269±3 m/s.
• Identified sub-ionospheric gravity waves propagating globally from this single source.
• Latent heat release from the plume was the dominant gravity wave source for over 12 hours.

Conclusions:

• The Hunga Tonga eruption generated a unique, global-scale atmospheric wave response.
• The observed gravity waves at sub-ionospheric heights and their speeds are unprecedented.
• The eruption serves as a critical natural experiment for understanding atmospheric responses to abrupt changes.
• Findings will aid in improving weather and climate models.