New York, Jan 6:
In a new study that sheds light on space weather’s impact on Earth, researchers have shown for the first time that plasma waves buffeting the planet’s radiation belts are responsible for scattering charged particles into the atmosphere.
The solar system and the bulk of the universe comprises matter which is mostly in the form of a plasma. Plasma is a very hot gas in which the electrons have been stripped from atoms to form a gas of negatively charged electrons and positively charged ions.
The belts are impacted by fluctuations in space weather caused by solar activity that can disrupt global positioning system satellites, communication systems, power grids and manned space exploration.
The space physicists at Dartmouth College are part of a NASA-sponsored team that studied the Van Allen radiation belts, which are doughnut-shaped belts of charged particles held in place by the Earth’s magnetosphere – the magnetic field surrounding our planet.
To study this phenomenon, balloons were launched from Antarctica where some of the best observations could be made.
As the falling electrons collide with the atmosphere, they produce X-rays and that is what the balloon instruments recorded.
“We are measuring those atmospheric losses and trying to understand how the particles are getting kicked into the atmosphere,” said study co-author Robyn Millan, associate professor at Dartmouth’s department of physics and astronomy.
The researchers obtained measurements in Antarctica in 2013 when the balloons and both the Geostationary Operational Environmental Satellite (GOES) and the Van Allen Probe satellites were near the same magnetic field line.
They put the satellite data into their model that tested the wave-particle interaction theory.
The results suggested the wave scattering was the cause of the particle fallout.
“This is the first real quantitative test of the theory,” Millan added.
The results appeared in the journal Geophysical Research Letters. (IANS)