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.
The Hunga Tonga-Hunga Ha’apai eruption on Jan. 15, 2022, caused many effects, some illustrated here, that were felt around the world and even into space. Some of those effects, like extreme winds and unusual electric currents were picked up by NASA’s ICON mission and ESA’s (the European Space Agency) Swarm. Image not to scale. Credits: NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith
“The volcano created one of the largest disturbances in space we’ve seen in
the modern era,” said Brian Harding, a physicist at University of California,
Berkeley, and lead author on a new paper discussing the findings. “It is
allowing us to test the poorly understood connection between the lower
atmosphere and space.”
ICON launched in 2019 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. In January 2022, as the spacecraft passed over South America, it
observed one such earthly disturbance in the ionosphere triggered by the South
Pacific volcano.
“These results are an exciting look at how events on Earth can affect
weather in space, in addition to space weather affecting Earth,” said Jim
Spann, space weather lead for NASA’s Heliophysics Division at NASA Headquarters
in Washington, D.C. “Understanding space weather holistically will ultimately
help us mitigate its effects on society.”
The GOES-17 satellite captured images of an umbrella cloud generated by the
underwater eruption of the Hunga Tonga-Hunga Ha’apai volcano on Jan. 15, 2022.
Crescent-shaped bow shock waves and numerous lighting strikes are also visible.
Credits: NASA Earth Observatory image by Joshua Stevens using GOES
imagery courtesy of NOAA and NESDIS
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.
“It's very surprising to see the electrojet be greatly reversed by
something that happened on Earth's surface,” said Joanne Wu, a physicist at
University of California, Berkeley, and co-author on the new study. “This is
something we’ve only previously seen with strong geomagnetic storms, which are
a form of weather in space caused by particles and radiation from the Sun.”
The new research, 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. A strong
equatorial electrojet is associated with redistribution of material in the
ionosphere, which can disrupt GPS and radio signals that are transmitted
through the region.
Understanding how this complex area of our atmosphere reacts in the face of
strong forces from below and above is a key part of NASA research. NASA’s
upcoming Geospace Dynamics Constellation, or GDC, mission will use a fleet of
small satellites, much like weather sensors on the ground, to track the electrical
currents and atmospheric winds coursing through the area. By better
understanding what affects electrical currents in the ionosphere, scientists
can be more prepared to predict severe problems caused by such disturbances.
Related Links
- Strong Winds
Power Electric Fields in the Upper Atmosphere, NASA’s ICON Finds
- Learn
more about ICON
- Learn
more about GDC
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Source: NASA
Mission Finds Tonga Volcanic Eruption Effects Reached Space | NASA
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