Scientists map waves in Earth’s radiation beltJune 1st, 2009 - 3:34 pm ICT by ANI
Washington, June 1 (ANI): Scientists at NASA have mapped chorus waves, a type of electromagnetic emission generated by electrons in Earth’s radiation belt.
Chorus waves play an important role in both accelerating and removing the energetic radiation belt electrons that can disrupt satellite electronics and disturb communications with ground-based operators.
To improve understanding of the origin and location of chorus waves, W. Li, J. Bortnik, B. Ni and R. M. Thorne, from the Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, California, US, use data from NASA’s five Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellites to create a new map of their distribution.
The authors find, in agreement with previous studies, that nightside chorus occurs only near the equator, whereas dayside chorus extends to higher latitudes.
In addition, they observe that amplitudes of chorus waves depend strongly on geomagnetic activity.
The most important new finding, the authors note, is that at a distance of more than 7 Earth radii (about 45,000 kilometers) on Earth’s dayside, moderate chorus is present more than 10 percent of the time (a much higher occurrence rate than on the night side) and persists even during periods of low geomagnetic activity.
The scientists believe that the new information could provide additional clues about the origin of dayside and night side chorus waves. (ANI)
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