Lightning is one of nature’s most spectacular and mysterious phenomena, yet there is much scientists still don’t know about it.
British researchers have found evidence that high-energy particles, which are blown toward Earth on the solar wind, play a role in triggering lightning on Earth.
These energized solar particles can travel from the sun at a rate as high as 800 kilometers per second, according to NASA.
The scientists from the University of Reading’s Department of Meteorology discovered a large and significant increase in lightning strikes across Europe for up to 40 days after solar winds struck our atmosphere.
The British study comes on the heels of a report released about a year ago by Russian researchers who found evidence that cosmic rays ‒ high-energy radiation generated by exploding stars deep in the universe that travel through the cosmos at the speed of light ‒ play a role in initiating lightning strikes.
Of course, the atmospheric conditions needed to produce lightning must first be present before it can be triggered either by cosmic rays, solar particles, or other phenomena, says the new study’s lead author, Chris Scott from the University of Reading.
While the specific mechanism behind the causes of lightning still remains a mystery, study scientists think the air’s electrical properties change when the charged solar particles hit the atmosphere.
The team’s research found the sun can generate particles that ‒ while not as energetic as cosmic rays ‒ are nonetheless able to penetrate our atmosphere, helping to enhance and speed the lightning process.
Solar wind is the continuous expulsion of material from the sun into space.
“It’s a bit like steam rising from a sauce-pan,” Scott said. “It’s the most energetic particles in the solar atmosphere that are able to escape and move out into space.”
He also suggested that if you think of the sun as a “leaky football,” it has various different jets that produce fast and relatively slower solar winds that can cause gusts and concentrations within the solar wind, all of which can intensity the sun’s magnetic field in space.
This concentration of the sun’s magnetic field also shields Earth from cosmic rays because they’re deflected by that magnetic field, which also accelerates the solar particles ahead of it in much the same way as a “surfer is accelerated by the wave he’s riding,” said Scott.
The research team noticed an increase in lightning when the streams of accelerated solar particles blew toward our planet.
They were able to make their findings after examining and analyzing lightning strike data from 2000 to 2005 recorded by the Met Office – the UK’s weather service – and its lightning detection system. They focused on lightning strikes that took place within a 500-kilometer radius in central England.
They compared that with data provided by NASA’S Advanced Composition Explorer (ACE) spacecraft, which has studied and measured the high energy particles contained within the solar wind since August 1997.
Scott and his team found that, for 40 days prior to the arrival of a solar wind at Earth, there was an average of 321 lightning strikes across the UK. But for the 40-day period after the arrival of the solar wind, that number increased to about 422. Their studies also revealed that the number of lightning strikes peaked between 12 and 18 days after the solar wind’s arrival.Video from the University of Reading Explains Where Lightning Comes From