Relativistic electron beams above thunderclouds

Abstract. Non-luminous relativistic electron beams above thunderclouds are detected by radio remote sensing with low frequency radio signals from 40–400 kHz. The electron beams occur 2–9 ms after positive cloud-to-ground lightning discharges at heights between 22–72 km above thunderclouds. The positive lightning discharges also cause sprites which occur either above or before the electron beam. One electron beam was detected without any luminous sprite occurrence which suggests that electron beams may also occur independently. Numerical simulations show that the beamed electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of 7 MeV to transport a total charge of 10 mC upwards. The impulsive current associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

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Relativistic electron beams above thunderclouds

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-7747-2011 ◽

2011 ◽

Vol 11 (15) ◽

pp. 7747-7754 ◽

Cited By ~ 18

Author(s):

M. Füllekrug ◽

R. Roussel-Dupré ◽

E. M. D. Symbalisty ◽

J. J. Colman ◽

O. Chanrion ◽

...

Keyword(s):

Electron Beam ◽

Relativistic Electron ◽

Electron Beams ◽

Low Frequency ◽

Electric Circuit ◽

Total Charge ◽

Relativistic Electron Beams ◽

Radio Signals ◽

Lightning Discharges ◽

Cloud To Ground Lightning

Abstract. Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency ∼40–400 kHz which they radiate. The electron beams occur ∼2–9 ms after positive cloud-to-ground lightning discharges at heights between ∼22–72 km above thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of ∼7 MeV to transport a total charge of ∼−10 mC upwards. The impulsive current ∼3 × 10−3 Am−2 associated with relativistic electron beams above thunderclouds is directed downwards and needs to be considered as a novel element of the global atmospheric electric circuit.

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Electromagnetic instability and stopping power of plasma for relativistic electron beams

Journal of Plasma Physics ◽

10.1017/s0022377800022431 ◽

1980 ◽

Vol 23 (3) ◽

pp. 423-432 ◽

Cited By ~ 18

Author(s):

Toshio Okada ◽

Keishiro Niu

Keyword(s):

Electron Beam ◽

Relativistic Electron ◽

Relativistic Electron Beam ◽

Electron Beams ◽

Collisionless Plasma ◽

Particle Interaction ◽

Stopping Power ◽

Relativistic Electron Beams ◽

Renormalization Theory ◽

Electromagnetic Instability

The stopping power of a plasma for a relativistic electron beam (REB) is derived by taking a Weibel-type electromagnetic instability into account in a collisionless plasma. A quasi-linear theory is developed to derive the stopping power of the plasma due to the electromagnetic instability. The wave–particle interaction by use of the renormalization theory leads to a saturation level of instability. Thus the purely growing electromagnetic instability, including the effect of the beam temperature, decides an effective stopping length of the REB in the plasma.

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