Plasma from the sun may generate lightning on Earth, say scientists

Lightning strikes are more frequent after streams of charged particles emanating from the sun strike the Earth's atmosphere, a new study has found.

David Rankin | www.rankinstudio.com
Lightning electrifies the evening sky over Utah, as an intense storm charges across southern Utah and northern Arizona. Photographer David Rankin captured this incredible scene from the southern end of Lake Powell, Utah, just after a sunset in Sept. 2013.

Solar winds hitting Earth may trigger an increase in lightning, a new study suggests.

The research finds an increase in the number of lightning strikes after the streams of plasma and particles known as solar wind arrive on Earth from the sun. Exactly why this correlation exists is unclear, but researchers say the interaction of solar particles might somehow prime the atmosphere to be more susceptible to lightning.

"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," study researcher Chris Scott, a professor in space and atmospheric physics at the University of Reading, said in a statement. [Images: Weird Red Sprite Lightning Caught on Camera]

Triggering lightning

The idea that lightning has roots in space is not a new one. In 2013, researchers found evidence that cosmic rays, which are high-energy beams of particles that likely originate in supernovas, may trigger lightning when they enter Earth's atmosphere. As they stream through the atmosphere, cosmic rays knock electrons off of atoms, potentially causing a chain reaction when those electrons knock into other atoms, dislodging even more electrons. In the 2013 study, researchers found that thunderclouds contain already-charged water droplets and ice crystals, meaning a normal level of cosmic rays could push these clouds over the edge into lightning territory.

Not all researchers are convinced that cosmic rays play a role in generating lightning. But if they do, strong solar winds' magnetism should strengthen the magnetic field that surrounds Earth, Scott said in a video about the new findings

Sun-lightning link?

That's not what Scott and his colleagues found, however. The researchers compared a record of lightning strikes from the U.K. Met Office lightning detection program from between 2000 and 2005. They focused on strikes within a 310-mile (500 kilometers) radius of central England. They then analyzed the lightning strikes in comparison with solar wind data from NASA's Advanced Composition Explorer (ACE) spacecraft.

Instead of seeing solar winds strengthening Earth's protective magnetic field, keeping cosmic rays out and preventing lightning, the researchers found the opposite. There were more lightning strikes after a significant gust of solar wind than before. After the arrival of a strong solar wind, there were an average of 422 lightning strikes in the study area over the next 40 days, compared with 321 on average in the 40 days prior.

The measurements might be the result of a greater number of lightning strikes, the researchers note, or it might be that strikes are stronger and are thus picked up on weather-monitoring instruments.

The lightning peaked 12 to 18 days after the solar winds arrived, researchers report today (May 14) in the journal Environmental Research Letters.

"As one of these streams washes past the Earth, it brings with it a population of energetic particles that penetrate the atmosphere and appear to help modulate lightning rates," Scott said in the video.

Solar winds are predictable, Scott said, so if the phenomenon proves legitimate, it might be possible to forecast times of increased lightning risk.

Follow Stephanie Pappas on Twitter and Google+. Follow us @livescienceFacebook & Google+. Original article onLive Science.

Copyright 2014 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.