When Tonga volcano erupted, ripples were felt in space

On January 15 this year, the world felt ripples as a shockwave from the Hunga Tonga-Hunga Ha‘apai volcano swept throughout the planet, the ripples also crossed the boundary of Earth to reach space.

Scientists have found an unusual formation of hurricane-speed winds and unusual electric currents in the ionosphere — Earth’s electrified upper atmospheric layer at the edge of space. The currents were formed hours after the eruptions.

Scientists found the sudden change in space when they analysed data from NASA’s Ionospheric Connection Explorer, or ICON, mission and ESA’s (the European Space Agency) Swarm satellites. Icon works to identify how Earth’s weather interacts with weather from space a relatively new idea supplanting previous assumptions that only forces from the Sun and space could create weather at the edge of the ionosphere.

“The volcano created one of the largest disturbances in space we’ve seen in the modern era. It is allowing us to test the poorly understood connection between the lower atmosphere and space,” Brian Harding, a physicist at the University of California said.

The spacecraft was passing over South America when it observed the earthly disturbance in the ionosphere triggered by the South Pacific volcano.

The study published in the journal Geophysical Research Letters is adding to scientists’ understanding of how the ionosphere is affected by events on the ground as well as from space.

What happened?

According to researchers, 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.

When these 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.

“These results are an exciting look at how events on Earth can affect the weather in space, in addition to space weather affecting Earth. Understanding space weather holistically will ultimately help us mitigate its effects on society,” Jim Spann, Nasa’s space weather lead said.

In the ionosphere, 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.