The electromagnetic dawn chorus is an unexplained phenomenon that occurs most often at sunrise or shortly after, that (with the proper radio equipment) resembles the sound of the birds' dawn chorus. Chorus is believed to be generated by a Doppler-shifted cyclotron interaction between anisotropic distributions of energetic (> 40 keV) electrons and ambient background VLF noise.[1][2] Dawn choruses occur more frequently during magnetic storms.
This phenomenon also occurs during aurorae, when it is termed an auroral chorus.
[edit] See also
- ^ Nunn, D.; Omura, Y.; Matsumoto, H.; Nagano, I.; Yagitani, S. (1997). "The numerical simulation of VLF chorus and discrete emissions observed on the Geotail satellite using a Vlasov code". J. Geophys. Res. 102: 27083–27098. doi:10.1029/97JA02518.
- ^ Trakhtengerts, V. Y. (1999). "A generation mechanism for chorus emission". Ann. Geophys. 17: 95–100. doi:10.1007/s00585-999-0095-4.
[edit] Further reading
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ELF/VLF Electromagnetic emissions
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Optical emissions
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