Tonga volcano eruption impacts observed up to edge of space

An explosive volcano that erupted near the Pacific island nation of Tonga in January sent hurricane-force winds and electric currents into the edge of space, according to an analysis of NASA data released Tuesday.

The Hunga Tonga-Hunga Ha'apai volcano erupted Jan. 15, sending a large plume of ash some 26 miles into the atmosphere and creating a shockwave that traveled about 1,000 feet per second and a tsunami that struck Nuku'alofa, Tonga, and American Samoa. The eruption killed at least six people.

The blast also caused atmospheric impacts, reaching into the ionosphere across the globe, according to a paper published in the journal Geophysical Research Letters.

The researchers said NASA data showed the volcano sent strong winds into thinner atmospheric layers, where they moved faster -- up to 450 mph -- until reaching the ionosphere and the edge of space.

Once in the upper atmosphere, the winds affected the equatorial electrojet, a thin ribbon of electrical current that flows east to west in the equatorial region of the ionosphere. The equatorial electrojet increased to five times its normal power and reversed directions.

"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."

NASA said the new research informs scientists' understanding of how events on Earth impact the upper atmosphere and the edge of space. A strong equatorial electrojet, for example, can disrupt GPS and radio signals in the region.


Photo file      Caption: Hunga Tonga-Hunga Ha'apai volcano erupted Jan. 15,