Researchers at the University of Colorado Boulder, led by undergraduate student Max Feinland, have discovered a new link between weather on Earth and space weather. Using satellite data, the team found that lightning storms on Earth can knock high-energy electrons out of the inner radiation belt, a region of space surrounding Earth. These “killer electrons” can be dangerous to satellites and astronauts in space and can even penetrate metal and circuit boards. The study was published in the journal Nature Communications.
The Earth’s radiation belts, generated by the planet’s magnetic field, consist of two regions: the inner belt starting over 600 miles above the surface and the outer belt beginning around 12,000 miles from Earth. These belts trap charged particles from the sun, forming a barrier between Earth’s atmosphere and the rest of the solar system. While scientists have known that high-energy electrons can fall from the outer belt to Earth, Feinland and his colleagues were the first to observe a similar phenomenon in the inner belt, highlighting the interconnectedness of Earth and space weather.
Lightning plays a crucial role in the process, as radio waves from lightning strikes can knock electrons out of the radiation belts, affecting the chemistry of Earth’s atmosphere. Feinland’s analysis of NASA data revealed clumps of high-energy electrons in the inner belt, contradicting the belief that the inner belt was stable and devoid of such particles. By comparing electron surges in the inner belt to records of lightning strikes in North America, the team found a correlation between the timing of lightning strikes and the appearance of high-energy electrons in the inner belt.
Following a lightning strike, radio waves set off a chain reaction in space, causing high-energy electrons to bounce between Earth’s northern and southern hemispheres. This process results in some electrons falling out of the belt and into the atmosphere. The team believes that these events may occur during periods of high solar activity, when the sun releases a significant number of high-energy electrons into the inner belt. Understanding these events better could help predict when they are likely to happen and improve the safety of people and electronics in orbit.
Feinland expressed his enthusiasm for the project, noting that it has fueled his passion for research. By studying the interaction between lightning storms on Earth and space weather, the team has shed light on a previously unknown phenomenon. This discovery underscores the importance of considering the interconnected nature of Earth and space, as events on our planet can have far-reaching consequences in space. With further research, scientists hope to better predict and mitigate the impacts of high-energy electrons on satellites and astronauts in space.