When the Hunga Tonga-Hunga Ha‘apai volcano erupted on Jan. 15, 2022, it sent atmospheric shock waves, sonic booms, and tsunami waves around the world. Now, scientists are finding the volcano’s effects also reached space.
Analyzing data from NASA’s Ionospheric Connection Explorer, or ICON, mission and ESA’s (the European Space Agency) Swarm satellites, scientists found that in the hours after the eruption, hurricane-speed winds and unusual electric currents formed in the ionosphere – Earth’s electrified upper atmospheric layer at the edge of space.
[...] When the volcano erupted, it pushed a giant plume of gases, water vapor, and dust into the sky. The explosion also created large pressure disturbances in the atmosphere, leading to strong winds. As the winds expanded upwards into thinner atmospheric layers, they began moving faster. Upon reaching the ionosphere and the edge of space, ICON clocked the windspeeds at up to 450 mph – making them the strongest winds below 120 miles altitude measured by the mission since its launch.
In the ionosphere, the extreme winds also affected electric currents. Particles in the ionosphere regularly form an east-flowing electric current – called the equatorial electrojet – powered by winds in the lower atmosphere. After the eruption, the equatorial electrojet surged to five times its normal peak power and dramatically flipped direction, flowing westward for a short period.
Brian J. Harding, Yen-Jung Joanne Wu, Patrick Alken, et al., Impacts of the January 2022 Tonga Volcanic Eruption on the Ionospheric Dynamo: ICON-MIGHTI and Swarm Observations of Extreme Neutral Winds and Currents, Geo. Res. Lett., 49, 9, 2022
DOI: 10.1029/2022GL098577 [doi.org]