Sun Burp Blasted Ozone Layer in 1859

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March 27, 2007 — A titanic burp of protons from the sun in 1859 appears to have temporarily weakened Earth's ozone layer, say scientists studying ice cores from Greenland. The evidence of the massive radiation event is in the form of an excessive amount of ozone-related nitrates in the ice from that year.

The huge September 1859 solar flare appears to have gushed 6.5 times the protons of the largest flare seen by modern science — which was in 1989. By modeling the space storm using nitrate data from the ice — compared with the modern event also detectable in the ice — the researchers estimate that more than three times as much ozone was destroyed by the 1859 event than in the 1989 blast.

The discovery is a hint at just how nasty the solar weather can get. Ozone is the gas that blocks ultraviolet-B (UV-B) light, which is particularly lethal to many life forms.

"The flare itself was observed directly," said researcher Brian Thomas of Washburn University in Kansas of the event. The flare was followed by a historic aurora light show and a geomagnetic storm that caused telegraph lines to spark and start fires.

In some places power surges created by the storm of charged solar particles blasting Earth’s magnetic field made it possible to operate telegraph systems without any added power, explains space weather forecaster Ron Zwickl, deputy director of NOAA’s Space Environment Center in Colorado.

"Most people right now think that’s the largest particle event," said Zwickl of the 1859 flare and storm of protons and other particles from the sun. The new research helps confirm that and zeroes-in on the effect the storm had on ozone worldwide.

Figuring out the 1859 event has been the center of study for many researchers because it seems to indicate that the sun is capable of much more violent weather than we’ve seen – or are prepared for, said Thomas.

Because much larger flares have been seen on nearby sun-like stars, it’s not impossible to imagine our sun doing the same, Thomas explained. The good news, adds Zwickl, is that those sorts of atmosphere-boiling solar events aren’t very common as a star grows older. Lucky for us that the sun is a middle-aged star.

It’s fairly certain that over the history of the Earth, exceptional solar activity has led to ozone destruction and allowed harmful UV-B rays to reach the ground, which may even have ties to some extinction events, according to some researchers.

"We’re not really sure what the upper limit of what the energy should be on these flares," Thomas told Discovery News.

A paper using the ice core data to model the historic solar blast’s effects on Earth’s atmosphere, with Thomas as the lead author, appears in the latest issue of Geophysical Research Letters.

"We need to know more about how these flares occur," said Thomas. "This gives us impetus to keep looking."