Researchers identified a "plasma plume" that protects Earth from dangerous solar storms.
The Earth's magnetic field spans from the Earth's core into outer space until it hits solar wind, which is a stream of particles flowing from the Sun, a Massachusetts Institute of Technology (MIT) news release reported.
When the magnetic field comes in contact with the Sun's magnetic field (a process called "magnetic reconnection") it can allow powerful magnetic storms to enter Earth's atmosphere. These storms can interfere with high-flying planes and spacecrafts.
Researchers have determined a process in the magnetosphere that helps keep out these forces. The researchers observed a "plume of low-energy plasma "that moves across magnetic field lines. Scientists have named the where the region where magnetic fields meet the "merging point."
"The Earth's magnetic field protects life on the surface from the full impact of these solar outbursts," John Foster, associate director of MIT's Haystack Observatory, said in the news release. "Reconnection strips away some of our magnetic shield and lets energy leak in, giving us large, violent storms. These plasmas get pulled into space and slow down the reconnection process, so the impact of the sun on the Earth is less violent."
The researchers used a ground-based system called GPS-TEC to absorb the plasma plume, which monitors radiowaves for signs of space-weather events.
The observations have helped researchers identify details about the plumes such as how often they occur and why some are more powerful than others.
The team looked at data from orbiting spacecrafts and found they had all passed through the same "cold, dense plasma plume" reaching all the way to the merging point.
"This higher-density, cold plasma changes about every plasma physics process it comes in contact with," Foster said. "It slows down reconnection, and it can contribute to the generation of waves that, in turn, accelerate particles in other parts of the magnetosphere. So it's a recirculation process, and really fascinating."
Foster compared the plume to a "river of particles" that works similarly to the Gulf stream by flowing in a strong circulation.
"What these types of studies are showing is just how dynamic this entire system is," Foster said.
