High-speed solar wind emanating from the sun may play a role in creating lightning strikes on Earth.
Lightning is still a mysterious phenomenon in many ways. One of the questions surrounding the events is how they happen at all. Air is an excellent electrical insulator, and physics suggest there is not enough of a charge in thunderstorms to create bolts of lightning.
Christopher Scott of the University of Reading in the UK believes cosmic rays may be responsible for triggering these events. The meteorologist theorizes that as charged particles from the solar wind strike atmosphere, they could strip electrons from the molecules in the air. This process ionizes the atoms, rendering them electrically conductive. This could then provide a pathway for electrical charges to travel. Cosmic rays are believed to cause a similar effect.
The solar wind is a large-scale release of plasma from our sun, which fluctuates temperature, pressure and velocity over time. This effect is periodic, with peaks happening once every 27 days. This solar wind, consisting of moving, charged particles, has its own magnetic field.
Scott suggests that when electrical storms are forming, meteorologists may be able to use knowledge of current conditions in solar wind, in order to better predict the severity of the tempest.
"[M]odulation of lightning by regular and predictable solar wind events may be beneficial to medium range forecasting of hazardous weather," researchers wrote in an article detailing their study.
Meterologists understand that liquid and ice particles colliding in the lower atmosphere can generate an electrical charge. These forces build, and will discharge to another cloud or to the ground when the electrical build-up overcomes resistance.
Lightning occurs most often between higher-level darker clouds and lower-altitude lighter clouds that deliver most of the precipitation. Many of the ultimate forces behind the formation of lightning still remain unknown.
"The paper finds that conditions in outer space are somehow affecting the production of lightning in thunderstorms. This is a very puzzling result, since it is not obvious how the two are connected. However, scientists still do not understand how lightning is initiated inside thunderstorms, so perhaps this work is providing a clue," Joseph Dwyer at the Florida Institute of Technology in Melbourne, Florida, told the media.
Temperatures within lightning can exceed 50,000 degrees Fahrenheit, several times hotter than the surface of the sun. Around 24,000 people are struck each year by lightning.
Study of the effect of solar wind on the production of lightning strikes on Earth was published in the journal Environmental Research Letters.