May 16, 2014
Lightning Strikes May Be More Intense Due To Solar Wind Activity
Brett Smith for redOrbit.com - Your Universe Online
From the ancient Greeks to Benjamin Franklin, man has long been fascinated by lightning.Previous research has found that the electrical bolts are caused by cosmic radiation and a new study has found that streams of high-energy particles from the Sun accelerated by the solar wind also play a role.
Published in the journal Environmental Research Letters, the new study revealed a considerable raise in lightning rates throughout Europe in the 40 days following the arrival of high-speed solar winds, which can move at over a million miles per hour from the Sun.
"Our main result is that we have found evidence that high-speed solar wind streams can increase lightning rates. This may be an actual increase in lightning or an increase in the magnitude of lightning, lifting it above the detection threshold of measurement instruments,” said study author Chris Scott, a space and atmospheric physics professor at the University of Reading.
"Cosmic rays, tiny particles from across the Universe accelerated to close to the speed of light by exploding stars, have been thought to play a part in thundery weather down on Earth, but our work provides new evidence that similar, if lower energy, particles created by our own Sun also affect lightning,” he added.
After analyzing data on lightning strikes and solar wind activity, the study team suggested that the electric properties in the air are in some way changed as the inbound charged solar particles from the solar wind clash with the atmosphere.
[ Watch the video: Where Does Lightning Come From? ]
Following the arrival of solar wind, the scientists found there was an average of 422 lightning strikes across the United Kingdom in the ensuing 40 days, compared to an average of 321 lightning strikes in the 40 days before the appearance of the solar wind. The pace of lightning strikes peaked between 12 and 18 days after the solar wind arrived.
"We propose that these particles, while not having sufficient energies to reach the ground and be detected there, nevertheless electrify the atmosphere as they collide with it, altering the electrical properties of the air and thus influencing the rate or intensity at which lightning occurs,” Scott said.
The researchers noted that the results could be essential for weather forecasters, since solar winds rotate with all the Sun, moving past the Earth at standard intervals and accelerating particles into Earth's atmosphere. Because these streams could be tracked, the study offers the possibility of predicting the severity of hazardous weather events weeks in advance.
"As the Sun rotates every 27 days these high-speed streams of particles wash past our planet with predictable regularity. Such information could prove useful when producing long-range weather forecasts,” Scott said.
"In increasing our understanding of weather on Earth we are learning more about its important links with space weather,” added study author Giles Harrison, head of Reading's Department of Meteorology. “Bringing the topics of Earth Weather and Space Weather ever closer requires more collaborations between atmospheric and space scientists, in which the University of Reading is already leading the way."