The sun might be around 149 million kilometres away from Earth but solar storms could still interfere with radio communications on our planet.
A team of researchers from Denmark, Canada and the United States reached this conclusion after they conducted a study on the solar storm that reached Earth on February 19, 2014.
This solar storm affected the ionosphere in all of Earth’s northern latitudes, NASA said. Scientists said solar storms can cause excessive electrical charge. In contrast, these can also deplete electrically charged particles in the Earth’s upper atmosphere.
A network of global navigation satellite systems (GNSS) documented the effects of solar storms on Greenland. Several geomagnetic observatories also monitored the occurrence.
According to NASA, solar storms usually include an eruption on the sun, called a coronal mass ejection (CME). A CME is a ‘vast cloud of electrically charged particles tossed into space.’ When these particles are hurled into space, they affect the interplanetary magnetic field in the solar system.
Subsequently, the CME’s cause ‘perturbations in the Earth’s magnetic field,’ NASA explained. These perturbations, called geomagnetic storms, result in unstable patches of excess electrons in the ionosphere.
Researchers observed this effect at an atmospheric region about 50 miles or 80 kilometers above the Earth.
Earth’s Ionosphere Loses Electrons After Solar Storms
Two powerful Earth-directed CMEs caused the 2014 geomagnetic storm. Initially, the solar storms caused patches of extra electrons in the ionosphere over northern Greenland.
Subsequently, scientists found broad areas south of the patches about 300 to 600 miles (500 to 1,000 kilometers) where electrons were almost non-existent. Per Hoeg of the National Space Research Institute said the electrons were ‘almost vacuumed out.’ This situation continued for several days.
Usually, electrons in the ionosphere reflect radio waves back to the ground level. Because of this, electrons make long-distance communications possible. Any depletion or increase of electron in the ionosphere can lead to failure in radio communications.
Whichever of the two situations occur, it will reduce the accuracy of GPS systems. In a worst-case scenario, a CME could damage satellites and harm electrical grids.
“We don’t know exactly what causes the depletion,” Attila Komjathy said in an article on NASA website. Komjathy of NASA’s Jet Propulsion Laboratory, Pasadena, California developed the software used to process the GNSS data.
He said there are two possible explanations on the occurrence. The CME could have caused the electrons to recombine with positively charged ions thus resulting in lack of excess electrons.
On the other hand, Komjathy cited a possible redistribution. In this instance, electrons are displaced and pushed away from the region.
Tibor Durgonics, a doctoral student at the Technical University of Denmark, is the lead author of the study. Meanwhile, Richard Langley of the University of New Brunswick, Canada contributed data sets and interpretation. The journal Radio Science published case study.