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hubie [soylentnews.org] writes:

New experiments have shown the source of the aurora borealis [energy.gov]

Researchers have demonstrated Alfvén waves accelerating electrons under conditions that correspond to Earth’s magnetosphere. The magnetosphere around the Earth contains ionized charged particles or plasma, one of the four types of matter along with solid, liquid, and gas. Plasmas are similar to both fluids and gases but also contain magnetic and electric fields. In 1942, Hannes Alfvén predicted that plasmas could support waves. These waves are today called Alfvén waves. The new experiments show that electrons “surf” on the electric field of the Alfvén wave in a phenomenon known as Landau damping. This means the energy of the wave is transferred to the accelerated electrons, like a surfer catching a wave and being continually accelerated as the surfer moves along with the wave. These electrons are the ultimate source of the light we call the aurora borealis.

The electrons stream along the magnetic field lines and run into atoms of oxygen and molecules of oxygen and nitrogen, knocking them into excited states resulting in their emissions of a wide range of colors [nps.gov].

Journal Reference:
Schroeder, J. W. R., et al., Laboratory measurements of the physics of auroral electron acceleration by Alfvén waves, Nature Communications 12, 3103 (2021).
DOI: 10.1038/s41467-021-23377-5 [doi.org]

Original Submission