Solar Storms | During powerful solar storms, high-energy particles are sent streaming into space, causing the areas above the poles to gain excessive electrical charge when they hit Earth’s upper atmosphere. But now, a new study has found that these storms can also have the opposite effect, draining certain regions until they are nearly depleted of electrically charged particles. Solar storms can rain a deluge of charged particles on our planet, creating spectacular aurora but also damaging satellites and electronics. Scientists have now discovered that these storms also have the opposite effect – they can drain the upper atmosphere above the Earth of almost all its charge.
In the study, researchers from Denmark, the US, and Canada analyzed a solar storm that hit Earth on February 19, 2014. The international team of researchers found
that these “electrically empty” areas were between 500 to 1,000 kilometers (300 to 600 miles) across and remained depleted of electrons for several days after the storm.
The Sun is constantly emitting a stream of electrically charged particles, the so-called solar wind. But sometimes there is an excess in this stream due to activities in the Sun, like coronal mass ejections that erupt solar plasma into space at incredible speeds. There are many factors that influence the type of particles and interactions above our planet. Understanding how the Sun shapes Earth’s space weather is crucial to guarantee the safety of astronauts as well as the satellites that keep us connected.
The electrons in the ionosphere normally reflect radio waves back to ground level, enabling long-distance radio communications. Both electron depletion and electron increases in this layer can possibly cause radio communications to fail, reduce the accuracy of GPS systems, damage satellites and harm electrical grids.
“We don’t know exactly what causes the depletion,” Komjathy said. “One possible explanation is that electrons are recombining with positively charged ions until there are no excess electrons. There could also be redistribution — electrons being displaced and pushed away from the region, not only horizontally but vertically.”
The paper is titled “Multi-instrument observations of a geomagnetic storm and its effects on the Arctic ionosphere: A case study of the 19 February 2014 storm.” Lead author Tibor Durgonics is a doctoral student at the Technical University of Denmark. Richard Langley (University of New Brunswick, Canada) provided data sets and interpretation.