By Casey Frye, CCNN Writer
Lightning is one of nature’s most mysterious forces. Even though it strikes 4 million times a day across the globe, just how exactly it forms inside a thunder cloud defies logic. Now, scientists believe our very own Sun may be influencing the sky-brightening zigzags of electricity, increasing their frequency with cosmic rays.
In order for researchers to create a lightning spark in the lab, they need an energy field of approximately 150 volts per meter. Since volts are basically a unit for measuring electric potential, there needs to be a fair amount in order for lightning to actually have the potential to take shape. However, what’s confusing is that there’s only 30 volts per meter inside thunder clouds, so how exactly does lightning ignite?
Well, according to one theory, the atmosphere that protects our Earth with a layer of gases gets electrically charged by cosmic rays sent rocketing through space by exploding stars. Because our Sun’s magnetic field can keep cosmic rays from entering our atmosphere, most scientists believe that increased solar activity would actually reduce lightning on Earth.
However, despite past studies showing anti-lightning effects from the Sun, researchers looked at solar activity within a much shorter period of a few weeks. Apparently, solar winds – streams of energy released from the upper atmosphere of the Sun – increased the chances of lightning, despite a reduction in cosmic rays charging up Earth’s atmosphere. One possible explanation is that charged particles from the Sun are hitchhiking on the winds, and while they aren’t as speedy as cosmic rays, they may very well increase electrical potential. This shocking breakthrough will certainly require more attention, since it’s overturning long-held assumptions about the Sun’s influence on lightning.
The Sun and other stars often have an aura of plasma called the corona, which is Latin for “crown”, and it reaches millions of kilometers into space. Sometimes, flashes of electromagnetic waves explode from solar flares near an active sunspot, kind of like a fiery space volcano. The National Oceanic and Atmospheric Administration says that this recent storm was very huge on the space weather scale. Yes, that’s a thing. Fortunately, the Earth has a magnetic field surrounding it, called the magnetosphere, which isn’t to be confused with Professor X’s archenemy. Still, such storms can cause spacecraft and satellite glitches! Mostly, though, it just resulted in some early 4th of July-style fireworks, by blasting the skies with auroral displays like the aurora borealis.
Images courtesy of NASA.