How did a third radiation belt appear in the Earth's upper atmosphere?

Jun 20, 2013
NASA's Van Allen probes. Credit: JHU/APL

(Phys.org) —Since the discovery of the Van Allen radiation belts in in the Earth's upper atmosphere in 1958, space scientists have believed that these belts consisted of two doughnut-shaped rings of highly charged particles—an inner ring of high-energy electrons and energetic positive ions, and an outer ring of high-energy electrons.

However, in February of this year, a team of scientists reported in the journal Science the surprising discovery of a previously unknown third radiation ring. This narrow ring had briefly circled the Earth between the inner and outer rings in September 2012 and then almost completely disappeared.

How did this temporary radiation belt appear and dissipate?

In new research, the radiation belt group in the UCLA Department of Atmospheric and Oceanic Sciences explains the development of this third belt and its decay over a period of slightly more than four weeks. The research is available in the online edition of the journal Geophysical Research Letters and will be published in an upcoming print edition.

By performing a "quantitative treatment of the scattering of relativistic electrons by electromagnetic whistler-mode waves inside the dense plasmasphere," the investigators were able to account for the "distinctively slow decay of the injected flux" and demonstrate why this unusual third is observed only at energies above 2 mega-electron-volts.

Understanding the processes that control the formation and ultimate loss of such relativistic electrons is a primary science objective of the NASA Van Allen Probe Mission and has important practical applications, because the enormous amounts of radiation the Van Allen belts generate can pose a significant hazard to satellites and spacecraft, as well to astronauts performing activities outside a spacecraft.

The current research was funded by the NASA, which launched the twin Van Allen probes in the summer of 2012.

Explore further: The source of the sky's X-ray glow

More information: www.nasa.gov/mission_pages/rbsp/main/index.html

Related Stories

NASA's BARREL mission launches 20 balloons

May 21, 2013

(Phys.org) —In Antarctica in January, 2013 – the summer at the South Pole – scientists released 20 balloons, each eight stories tall, into the air to help answer an enduring space weather question: ...

20 NASA balloons studying the radiation belts

Feb 04, 2013

In the bright, constant sun of the Antarctic summer, a NASA-funded team is launching balloons. There are twenty of these big, white balloons, each of which sets off on a different day for a leisurely float ...

Tiny CREPT instrument to study the radiation belts

Feb 14, 2013

A smaller version of an instrument now flying on NASA's Van Allen Probes has won a coveted spot aboard an upcoming NASA-sponsored Cubesat mission—the perfect platform for this pint-size, solid-state telescope.

The radiation belt storm probes

Aug 31, 2012

(Phys.org)—Since the dawn of the Space Age, mission planners have tried to follow one simple but important rule: Stay out of the van Allen Belts. The two doughnut-shaped regions around Earth are filled ...

Recommended for you

The source of the sky's X-ray glow

11 hours ago

In findings that help astrophysicists understand our corner of the galaxy, an international research team has shown that the soft X-ray glow blanketing the sky comes from both inside and outside the solar system.

End dawns for Europe's space cargo delivery role

20 hours ago

Europe will close an important chapter in its space flight history Tuesday, launching the fifth and final robot ship it had pledged for lifeline deliveries to the International Space Station.

Giant crater in Russia's far north sparks mystery

Jul 26, 2014

A vast crater discovered in a remote region of Siberia known to locals as "the end of the world" is causing a sensation in Russia, with a group of scientists being sent to investigate.

NASA Mars spacecraft prepare for close comet flyby

Jul 26, 2014

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

Bacteria manipulate salt to build shelters to hibernate

Jul 25, 2014

For the first time, Spanish researchers have detected an unknown interaction between microorganisms and salt. When Escherichia coli cells are introduced into a droplet of salt water and is left to dry, b ...

How do we terraform Venus?

Jul 25, 2014

It might be possible to terraform Venus some day, when our technology gets good enough. The challenges for Venus are totally different than for Mars. How will we need to fix Venus?

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Tangent2
2.3 / 5 (6) Jun 20, 2013
Gotta love how this article doesn't even mention the HOW this happened. I had to go to the actual archive article to find out, but I'll save the rest of you some time of digging through the article:

"The ring formed on September 3, 2012 during the main phase of a magnetic storm due to the partial depletion of the outer radiation belt for L > 3.5, and this remnant belt of relativistic electrons persisted at energies above 2 MeV, exhibiting only slow decay, until it was finally destroyed during another magnetic storm on October 1."