Dawn chorus (electromagnetic)
The electromagnetic dawn chorus is a phenomenon that occurs most often at or shortly after dawn local time. With the proper radio equipment, dawn chorus can be converted to sounds that resemble birds' dawn chorus (by coincidence).
The electromagnetic dawn 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. These energetic electrons are generally injected into the inner magnetosphere at the onset of the substorm expansion phase. Dawn choruses occur more frequently during magnetic storms.
- Auroral chorus
- Hiss (electromagnetic)
- Whistler (radio)
- Cluster One, a Pink Floyd track using sferics and dawn chorus as an overture
- 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. Bibcode:1997JGR...10227083N. doi:10.1029/97JA02518.
- Trakhtengerts, V. Y. (1999). "A generation mechanism for chorus emission". Ann. Geophys. 17: 95–100. Bibcode:1999AnGeo..17...95T. doi:10.1007/s00585-999-0095-4.
- Stephen P. McGreevy's ground-based ELF-VLF recordings at the Library of Congress Web Archives (archived 2002-09-13)
- Natural VLF Radio - Sounds of Space Weather
- Space-Weather Sounds - the Mysterious and Beautiful Natural Radio Phenomena of Earth at the Wayback Machine (archived August 22, 2014)
- Clearest record yet (2012) by NASA spacecraft