The generation of whistler, lower hybrid, and magnetosonic waves by satellites passing through ionospheric magnetic field aligned irregularities

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A numerical study is carried out for the generation of lower hybrid, whistler, and compressional Alfvén (magnetosonic) waves by satellites crossing magnetic field aligned irregularities or striations. Satellites and space debris propagating at an altitude of about 300 km with a velocity of 7.7 km/s perpendicular to the magnetic field generate a wake of lower hybrid waves with a wavelength of ∼1 m and frequencies near the lower hybrid frequency ∼7.87 kHz. In the presence of small-scale striations having widths below 0.5 m, the satellite-generated lower hybrid waves efficiently mode convert to whistler waves with frequencies slightly above the lower hybrid frequency, which propagate within a cone ∼19.5° to the background magnetic field. For larger striations having widths of 1 m and above, the interaction with satellites leads to modulated pulses of whistler waves as well as to magnetosonic waves propagating at large angles to the magnetic field, with frequencies below the lower hybrid frequency. The results are consistent with recent observations during conjunctures between satellites, where the observed frequencies ranged from the ion cyclotron frequency to the lower hybrid frequency [Bernhardt et al., Phys. Plasmas 30, 092106 (2023)].