John Metcalfe was CityLab’s Bay Area bureau chief, covering climate change and the science of cities.
Scientists say the star's magnetic field may be ratcheting up strikes by 50 percent.
When one is caught in a major thunderstorm, with lightning bolts cracking left and right, what's on the brain is probably not, Damn you, sun! But perhaps we should blame our life-giving star for making storms extra-intense, say researchers who claim it's creating spikes in British lightning.
The sun is not only a gigantic ball of nuclear fire but an immense tangle of magnetic lines snaking into space, constantly changing in orientation and intensity. And that's where the connection to lightning begins, finds Matt Owens and other University of Reading scientists in Environmental Research Letters.
When the solar magnetic field bends one way, the earth's own field warps in another direction. That allows particles whipping through the universe called cosmic rays to more easily penetrate our atmosphere. Cosmic rays are known to play a role in sparking lightning during storms, thus the theory that there are fiercer electric fusillades when the solar field is "holding open" our planet's magnetic curtain.
After sorting through weather data, Owens and company calculated that the sun's field, when bent in a certain direction, increased thunderstorms by an astonishing 50 percent in the U.K. It has an effect outside the U.K., too, probably leading to dips in lightning activity elsewhere. "[W]e propose a redistribution of lightning, rather than a global change in the lightning rate," say the researchers.
So why should anybody care? If scientists know how the solar field is moving, it could help create better forecasts of major thunderstorms weeks before they happen. Says Owens:
"Scientists have been reliably predicting the solar magnetic field polarity since the 1970s by watching the surface of the Sun. We just never knew it had any implications on the weather on Earth. We now plan to combine regular weather forecasts, which predict when and where thunderclouds will form, with solar magnetic field predictions. This means a reliable lightning forecast could now be a genuine possibility."