A NASA-sponsored research team from Dartmouth demonstrated that plasma waves pounding the planet’s radiation belts are responsible for distributing charged particles into the atmosphere. This type of solar activity can fluctuate and disrupt communication systems, GPS satellites, manned space exploration and power grids.
The research team frequently studies the Van Allen radiation belts, which are donut shaped belts of charged particles in the Earth’s magnetic field. The Dartmouth researchers wanted to better study these radiation belts, so they launched an instrument-laden BARREL (Balloon Array for Radiation belt Relativistic Electron Losses) balloon over Antarctica.
The purpose of the balloon was to evaluate the fallout of electrons from the Earth’s radiation belts due to electromagnetic waves. They aimed to simultaneously obtain measurements of plasma and scattered particles near the equator, and measurements of a plasma wave known as electromagnetic ion cyclotron waves.
“The Van Allen Probes measure particle, electric and magnetic fields, or basically everything in the radiation belt environment, including the electrons, which descend following the Earth’s magnetic field lines that converge at the poles. This is why the balloons are launched from Antarctica, where some of the best observations can be made. As the falling electrons collide with the atmosphere, they produce X-rays and that is what the balloon instruments are actually recording,” according to researchers.
“We are measuring those atmospheric losses and trying to understand how the particles are getting kicked into the atmosphere. Our main focus has been really on the processes that are occurring out in space. Particles in the Van Allen belts never reach the ground, so they don’t constitute a health threat. Even the X-rays get absorbed, which is why we have to go to balloon altitudes to see them,” Robyn Millan, associate professor at Dartmouth, said.
Researchers also gathered measurements from balloons in 2013 over Antarctica from the Geostationary Operational Environmental Satellite (GOES) and Van Allen Probe satellites, however; these recent studies yield the most detailed data ever collected via balloons and satellites.
