Radiation Belts Around Earth Adversly Affecting Satellites

December 07, 1998

Much of the energetic electron activity in Earth's radiation belts, once thought to be generated by the sun and solar wind, actually is accelerated to light-speed by Earth's own magnetic shell, creating periodic havoc with satellites.

Daniel Baker, director of the University of Colorado at Boulder's Laboratory for Atmospheric and Space Physics, said new findings indicate that electrons in the Van Allen radiation belts circling Earth are energized to speeds much higher than researchers had thought. The Van Allen belts are two main zones in Earth's magnetosphere where charged particles are confined by the planet's magnetic fields.

"We used to think that the Van Allen Belts slowly waxed and waned and were not particularly dynamic," he said. "But these belts have now been shown to be powerful, energetic particle accelerators, generating excitement and awe in the scientific community."

Named for physicist James Van Allen who discovered them in 1958, the belts consist of two doughnut-shaped regions containing electrons and protons centered thousands of miles above Earth's surface.

Speeding particles in the near-Earth environment from the sun, solar wind and Earth's magnetosphere -- commonly known as "killer electrons" -- have had a dramatic effect on human technological systems, said Baker. "This includes many of the satellites that are up there now and future spacecraft like the space station, which have the potential to be severely impaired electronically by light-speed electrons."

Baker presented his latest findings at the fall meeting of the American Geophysical Union held Dec. 6 to Dec. 10 in San Francisco.

A paper authored by Baker and colleagues in the Oct. 6 issue of Eos, a publication of AGU, indicate an intense flux of electrons from Earth's magnetosphere likely played an important role in the failure of the Galaxy 4 spacecraft last May. The event led to a temporary loss of pager service to 45 million customers.

Activity in the two known Van Allen radiation belts grew so intense in May 1998 that a new belt was created, said Baker. The activity was detected by several NASA spacecraft, including NASA's WIND, SAMPEX and Polar satellites, all part of the multi-agency International Solar and Terrestrial Physics Program.

"We have gotten a much clearer picture of cosmic particle acceleration in the Van Allen Belts from these satellites," said Baker, an investigator on the Polar and WIND experiments. "New observations indicate very rapid changes in these belts on timescales of months, weeks, days, hours and even seconds."

The new findings that killer electrons can be accelerated inside the Van Allen belts may help scientists better protect satellites by powering them down or using back-up systems during electronic storms. "This knowledge will help us better prepare for the next solar maximum period when the sun is most active, expected in late 2000 or early 2001," said Baker.

Scientists plan to coordinate observations from more than a dozen spacecraft, which may allow them to produce "space weather" maps of particle acceleration that could be potentially damaging to satellites. "In many ways, every spacecraft will act as a high-energy detector," said Baker.

In addition, CU-Boulder recently was selected to design, build, operate and control a NASA satellite that will study the response of Earth's Van Allen radiation belts to the powerful solar wind. The $12.8 million satellite project, known as the Inner Magnetosphere Explorer, or IMEX, is being directed by Professor John Wygant of the University of Minnesota in Minneapolis.

Co-Investigators include Baker and LASP Associate Researcher Xinlin Li. CU-Boulder is expected to receive about half of the funding for the project.

IMEX will study the energetic charged particles -- primarily protons and electrons -- comprising Earth's radiation zones. In 1996, Baker's research indicated the operational failure of a Canadian communications satellite. Anik E1, appeared to be linked to severe space weather.
-end-


University of Colorado at Boulder

Related Solar Wind Articles from Brightsurf:

Wind beneath their wings: Albatrosses fine-tuned to wind conditions
A new study of albatrosses has found that wind plays a bigger role in their decision to take flight than previously thought, and due to their differences in body size, males and females differ in their response to wind.

New research deepens understanding of Earth's interaction with the solar wind
A team of scientists at PPPL and Princeton University has reproduced a process that occurs in space to deepen understanding of what happens when the Earth encounters the solar wind.

Hydropower plants to support solar and wind energy in West Africa
Study maps smart electricity mix composed of solar, wind and hydropower for West Africa -- regional cooperation can provide up to 60% reliable and clean electricity

Solar and wind energy sites mapped globally for the first time
Researchers at the University of Southampton have mapped the global locations of major renewable energy sites, providing a valuable resource to help assess their potential environmental impact.

New research helps explain why the solar wind is hotter than expected
When the sun expels plasma, the solar wind cools as it expands through space -- but not as much as the laws of physics would predict.

Solar wind samples suggest new physics of massive solar ejections
A new study led by the University of Hawai'i (UH) at Mānoa has helped refine understanding of the amount of hydrogen, helium and other elements present in violent outbursts from the Sun, and other types of solar 'wind,' a stream of ionized atoms ejected from the Sun.

Supporting structures of wind turbines contribute to wind farm blockage effect
Much about the aerodynamic effects of larger wind farms remains poorly understood.

Parker Solar Probe traces solar wind to its source on sun's surface: coronal holes
New data from the Parker Solar Probe, which got closer to the sun than any other spacecraft, allowed physicists to map the source of a major component of the solar wind that continually peppers Earth.

Closest-ever approach to the sun gives new insights into the solar wind
The Parker Solar Probe spacecraft, which has flown closer to the sun than any mission before, has found new evidence of the origins of the solar wind.

SwRI-built instrument confirms solar wind slows farther away from the Sun
Measurements taken by the Solar Wind Around Pluto (SWAP) instrument aboard NASA's New Horizons spacecraft are providing important new insights from some of the farthest reaches of space ever explored.

Read More: Solar Wind News and Solar Wind Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.