FIREBIRD II and NASA mission locate whistling space electrons' origins

November 15, 2017 by Mara Johnson-Groh, NASA's Goddard Space Flight Center
The Van Allen Belts, shown in green in this illustration, are concentric doughnut-shaped belts filled with charged particles, trapped by Earth's magnetic field. Credit: Tony Phillips/NASA

Scientists have long known that solar-energized particles trapped around the planet are sometimes scattered into Earth's upper atmosphere where they can contribute to beautiful auroral displays. Yet for decades, no one has known exactly what is responsible for hurling these energetic electrons on their way. Recently, two spacecraft found themselves at just the right places at the right time to witness first hand both the impulsive electron loss and its cause.

New research using data from NASA's Van Allen Probes mission and FIREBIRD II CubeSat has shown that a common plasma wave in space is likely responsible for the impulsive loss of high-energy electrons into Earth's atmosphere. Known as whistler mode chorus, these waves are created by fluctuating electric and magnetic fields. The waves have characteristic rising tones—reminiscent of the sounds of chirping birds—and are able to efficiently accelerate electrons. The results have been published in a paper in Geophysical Review Letters.

"Observing the detailed chain of events between and electrons requires a conjunction between two or more satellites," said Aaron Breneman, researcher at the University of Minnesota in Minneapolis, and lead author on the paper. "There are certain things you can't learn by having only one satellite—you need simultaneous observations at different locations."

The study combined data from FIREBIRD II, which cruises at a height of 310 miles above Earth, and from one of the two Van Allen Probes, which travel in a wide orbit high above the planet. From different vantage points, they could gain a better understanding of the chain of cause and effect of the loss of these high-energy electrons.

Whistler waves as heard by the EMFISIS instrument aboard NASA’s Van Allen Probes as it passed around Earth. Credit: NASA/University of Iowa

Far from being an empty void, the space around Earth is a jungle of invisible fields and tiny . It's draped with twisted and swooping electrons and ions. Dictating the movements of these particles, Earth's magnetic environment traps electrons and ions in concentric belts encircling the planet. These belts, called the Van Allen Radiation Belts, keep most of the high-energy particles at bay.

Sometimes however, the particles escape, careening down into the atmosphere. Typically, there is a slow drizzle of escaping electrons, but occasionally impulsive bunches of particles, called microbursts, are scattered out of the belts.

Late on Jan. 20, 2016, the Van Allen Probes observed chorus waves from its lofty vantage point and immediately after, FIREBIRD II saw microbursts. The new results confirm that the chorus waves play an important role in controlling the loss of —one extra piece of the puzzle to understand how high-energy electrons are hurled so violently from the radiation belts. This information can additionally help further improve space weather predictions.

Explore further: NASA listens in as electrons whistle while they work

More information: A. W. Breneman et al. Observations directly linking relativistic electron microbursts to whistler mode chorus: Van Allen Probes and FIREBIRD II, Geophysical Research Letters (2017). DOI: 10.1002/2017GL075001

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cantdrive85
1 / 5 (4) Nov 15, 2017
"There are certain things you can't learn by having only one satellite—you need simultaneous observations at different locations."

This is a very salient fact that is relevant to many aspects of space plasma phenomena, don't tell jonesdumb though as he is convinced his narrow myopic POV is valid.
Captain Stumpy
5 / 5 (3) Nov 15, 2017
@idiot illiterate pseudoscience eu cult member
"There are certain things you can't learn by having only one satellite—you need simultaneous observations at different locations."

This is a very salient fact that is relevant to many aspects of space plasma phenomena...
1- false claim

because

2- PPPL.gov
and
https://scholar.g...+physics

epic fail showing that eu cult members are illiterate and don't know about the multiple plasma physics labs all around the world that prove their idiocy is cult driven dogma based upon delusional claims from non scientists attempting to create a new religion (a la Hubbard)
jonesdave
5 / 5 (3) Nov 15, 2017
"There are certain things you can't learn by having only one satellite—you need simultaneous observations at different locations."

This is a very salient fact that is relevant to many aspects of space plasma phenomena, don't tell jonesdumb though as he is convinced his narrow myopic POV is valid.


Oh, I think multiple spacecraft observations are just fine! Such as:

Ion-scale secondary flux ropes generated by magnetopause reconnection as resolved by MMS
http://onlinelibr...747/full
jonesdave
5 / 5 (2) Nov 15, 2017
And just in case CD doesn't know what MMS is:
https://en.wikipe..._Mission

There was an equivalent ESA mission called Cluster;
https://en.wikipe...cecraft)

It (they) saw some interesting things too:
Cluster encounter of a magnetic reconnection diffusion region in the near-Earth magnetotail on September 19, 2003
http://onlinelibr...794/full

Forrest Mozer is a co-author on that paper. He has co-authored with Falthammar, and was often cited by him.
jonesdave
5 / 5 (3) Nov 15, 2017
And one shouldn't forget THEMIS;

https://en.wikipe...i/THEMIS

THEMIS observations of modified Hall fields in asymmetric magnetic field reconnection
http://onlinelibr...033/full

Mozer, again.
cantdrive85
1 / 5 (5) Nov 15, 2017
One of these days you will understand the difference between measurements and interpretation. Claims of MRx involves interpretation of the measurements.
Captain Stumpy
5 / 5 (4) Nov 15, 2017
@idiot moronic illiterate pseudoscience eu cult member cd
One of these days you will understand the difference between measurements and interpretation. Claims of MRx involves interpretation of the measurements
well that should be easily proven then with experimentation and demonstration like the 100K measurements and experiments at PPPL

so where is your scientific refute?

not your "because [x] said so..." refute, which is argument from authority
nor your "because [x] is just wrong" which is argument from ignorance
nor your russels teapot
nor your "because thunderdolts..." pseudoscience

no claims
show where the MRX experiments are debunked using the same methodology that current electrical engineers use to show MRX is real

captain obvious says: idiot illiterate troll is illiterate idiot
jonesdave
5 / 5 (4) Nov 15, 2017
captain obvious says: idiot illiterate troll is illiterate idiot


Fair point.
jonesdave
5 / 5 (4) Nov 15, 2017
One of these days you will understand the difference between measurements and interpretation. Claims of MRx involves interpretation of the measurements.


And Mozer & Falthammar interpreted them as MRx. End of argument. Eh?
691Boat
5 / 5 (3) Nov 16, 2017
One of these days you will understand the difference between measurements and interpretation. Claims of MRx involves interpretation of the measurements.


Not quite sure what the point of taking measurements is if one can not interpret them.

"Look, I have 63MB of measurement data from the latest plasma ignoramus experiment we did! So many beautiful columns and rows of data!"
"Great. Go ahead and store that somewhere, since we can't analyze and interpret it per CD85. Good job taking those measurements."

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