When the Tonga volcano erupts, people feel ripples in space
On January 15 of this year, the world felt ripples as a shock wave from the Hunga Tonga-Hunga Ha’apai volcano swept across the planet, the ripples also crossing the boundaries of Earth to reach space.
Scientists have found unusual wind formations at lightning speeds and unusual electrical currents in the ionosphere, the electrically charged upper layer of Earth’s atmosphere at the edge of space. Streams of water are formed several hours after the eruption.
Scientists detect sudden change in space as they analyzed data from NASA’s Ionospheric Connection Explorer, or ICON, and ESA (European Space Agency) Swarm satellites. The icon works to determine how Earth’s weather interacts with weather from space, a relatively new idea that replaces 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 that we have seen in the modern era. It is allowing us to examine a poorly understood link between the lower atmosphere and space,” said Brian Harding, a physicist at the University of California.
The spacecraft was passing through South America when it observed disturbances in the ionosphere caused by South Pacific volcanoes.
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.
According to researchers, when the volcano erupted, it sent a huge amount of gas, water vapor and dust into the sky. The explosion also created large pressure disturbances in the atmosphere, resulting in strong winds.
As these winds expand upward into thinner layers of the atmosphere, they begin to move faster. Upon reaching the ionosphere and the edge of space, ICON throttled wind speeds up to 450 mph, making them the strongest winds below 120 miles. as measured by the mission since launch.
“These results are an exciting look at how events on Earth can affect space weather, beyond how space weather affects Earth. Understanding space weather holistically Jim Spann, Nasa’s space weather team leader.
In the ionosphere, extreme winds also affect electric currents. Particles in the ionosphere regularly form an eastward current known as an equatorial current supplied by winds in the lower atmosphere. After the eruption, the equatorial jet increased to 5 times its normal peak power and reversed direction abruptly, flowing westward for a short time.