Fixed rings of electrically charged particles surround the earth and other planets. Now, a research group has conducted surveys on waves traveling through this magnetic, electrically charged environment, known as the magnetosphere, deepening the understanding of the region and its interaction with our own planet, and opening new ways of studying other planets across the galaxy.
The researchers, led by Eun-Hwa Kim, physicist at the US Department of Energy (DOE) Princeton Plasma Physics Laboratory (PPPL), examined a type of wave traveling through the magnetosphere. These waves, called electromagnetic ion cyclotron (EMIC) waves, reveal the temperature and density of the plasma particles within the magnetosphere, among other properties.
"Waves are a kind of signal from the plasma," said Kim, leading author of a paper that reported the results in JGR Space Physics . "Therefore, EMIC waves can be used as diagnostic tools to reveal some of the plasma properties."
Kim and researchers from Andrews University in Michigan and Kyung Hee University in South Korea focused their research on fashion transformation, how some EMIC waves are formed. During this process, other waves that compress along the direction they travel from outer space collide with the Earth's magnetosphere and trigger the formation of EMIC waves, which then zoom out at a certain angle and polarization ̵
Using PPPL computers, the researchers performed simulations showing that these fashion-converted EMIC waves can propagate through the magnetosphere along magnetic field lines at a normal angle less than 90 degrees relative to the boundary of the region of space. Knowing such properties enables physicists to identify EMIC waves and collect information about the magnetosphere with limited initial information.
A better understanding of the magnetosphere can provide detailed information on how soil and other planets interact with their space environment. For example, the waves can let scientists determine the density of elements such as helium and oxygen in the magnetosphere, and learn more about the flow of charged particles from the sun producing aurora borealis.
In addition, engineers use waves similar to EMIC waves to help heat plasma in donut-shaped magnetic fusion devices called tokamaker. So studying the behavior of the waves in the magnetosphere could deepen the insight about the creation of fusion energy, which occurs when plasma particles collide to form heavier particles. Researchers around the world are trying to replicate fusion on earth for a virtually inexhaustible power supply to generate electricity.
Knowledge of EMIC waves can thus offer great advantages. "We are really keen to understand the magnetosphere and how it mediates the effect space weather has on our planet," Kim said. "Being able to use EMIC waves as diagnostics would be very helpful."
With a spin on the plasma space towers with NASA observations
Eun-Hwa Kim et al., Electron inertia effects on linearly polarized electromagnetic ion cyclotron waves at Earth's magnetosphere, Journal of Geophysical Research: Space Physics (2019). DOI: 10,1029 / 2019JA026532
Scientists deepen understanding of magnetic fields surrounding the Earth and other planets (2019, July 12)
July 12, 2019
This document is subject to copyright. Except for any fair trade for private study or research, no
Some may be reproduced without written permission. The content is provided for informational purposes only.