Orbiting Satellite Missions Detected that Space Also Felt the Effects of the Tonga Volcanic Eruption

This illustration shows the effects of the Hunga Tonga-Hunga Ha’apai eruption on the ocean, layers of the atmosphere, and space. Credit: NASA’s Goddard Space Flight Center/Mary Pat Hyrbyk-Keith.

On January 15, 2022, the Hunga Tonga-Hunga Ha’apai submarine volcano erupted in the Pacific Ocean, 65 kilometers north of Tonga’s main island, Tongatapu. The eruption sent atmospheric shockwaves around the world several times, produced an ash cloud the size of France in area, and has been deemed the largest explosive eruption of the 21st century. At the time of the eruption, NASA’s Ionospheric Connection Explorer (ICON) mission and ESA’s Swarm satellites were monitoring the dynamic zone where Earth’s atmospheric weather and space weather meet, also known as the ionosphere. Before the launch of the ICON mission, it was uncertain if weather from Earth could interact with weather from space due to electromagnetic radiation and charged particles emitted by the Sun interacting with Earth’s electromagnetic field. However, in the hours following the eruption, these satellites detected hurricane-speed winds and electric currents in the ionosphere showing that the Tonga eruption caused the largest disturbance in space detected this century.

Based on the data from the ICON mission, Brian Harding (University of California, Berkeley) and his team hypothesized that the large pressure disturbances from the Tonga eruption created strong winds that expanded as they migrated into the thinner upper atmosphere. These fast winds in the upper atmosphere, in turn, affected the electrical currents in the ionosphere. Usually, particles in the ionosphere follow an eastward electric current, known as the equatorial electrojet. During the Tonga eruption, the equatorial electrojet surged in power by up to approximately five times and flowed in an opposite westward direction for a short period. The Tonga volcanic eruption proved to be an insightful opportunity, showing that Earth’s lower atmosphere events can measurably impact space weather in the ionosphere. READ MORE