A.S. Potapovb aSchmidt Institute of Physics of the Earth of the Russian Academy of Sciences, Bolshaya Gruzinskaya ul. 10, Moscow, 123995, Russian Federation bInstitute of Solar-Terrestrial Physics, Lermontova str. 125a, Irkutsk, 664033, Russian Federation
This review is devoted to ultra-low-frequency electromagnetic waves of a natural origin. A variety of frequency-modulated waves whose sources are located in the ionosphere, in the radiation belt, on the periphery of the magnetosphere, and in the solar wind in front of the magnetosphere bow shock are considered. The main focus is on the mechanisms of the formation of frequency modulation. Analysis of frequency modulation gives us information about the processes of excitation and propagation of waves, as well as about physical conditions in places of excitation and along signal propagation paths. Relevant open question about the physics of frequency-modulated waves are indicated.
Keywords: plasma, solar wind, magnetosphere, radiation belt, electromagnetic waves, ion cyclotron instability, dispersion, Doppler effect PACS:94.20.ws, 94.30.−d, 94.30.Ms (all) DOI:10.3367/UFNe.2020.06.038777 URL: https://ufn.ru/en/articles/2021/5/b/ Citation: Guglielmi A V, Potapov A S "Frequency-modulated ULF waves in near-Earth space" Phys. Usp.64 452–467 (2021)