Physical Effects of the Yushu Meteoroid: 3

Abstract

A comprehensive modeling of the processes in all geospheres caused by the fall and explosion of the Yushu meteoroid in the Qinghai Province (People’s Republic of China) on December 22, 2020, was performed. The magnetic, electrical, electromagnetic, ionospheric, and seismic effects, as well as the effects of acoustic-gravity waves, were estimated. It is shown that the magnetic effect of turbulence was insignificant. The magnetic effect of the ionospheric currents and the current in the meteoroid’s wake could be significant (~1 nT). Due to the capture of electrons in the field of the atmospheric gravity wave, the magnetic effect could reach the order of 1 nT. The effect of the external electric field could lead to a short-term current pulse of up to 10⁴ A. The electrostatic effect could be accompanied by the accumulation of a charge of 1–10 mC with an electric field strength of approximately 1 MV/m. The flow of electric current in the wake could lead to the emission of an electromagnetic pulse in the frequency range of approximately 10 kHz with a strength of 3–30 V/m. It was found that the electromagnetic effect of infrasound could be significant (approximately 3–20 V/m and 10–60 nT). Absorption of the shock wave at the heights of the dynamo region of the ionosphere (100–150 km) could be accompanied by the generation of secondary atmospheric gravity waves with a relative amplitude of 0.1–1. The passage of the meteoroid led to the formation of a plasma wake and to a noticeable disturbance of not only the lower but also the upper atmosphere at distances of at least 1000 km. The occurrence of an electrophonic effect seems unlikely. The possibilities of generating ion and magnetic sound by infrasound as well as gradient-drift and drift-dissipative instabilities are discussed. The magnetic, electrical, and electromagnetic effects discussed in this article partially fill in the gaps in the theory of the physical effects of meteoroids in the Earth–atmosphere–ionosphere–magnetosphere system. The magnitude of the earthquake caused by the meteoroid explosion did not exceed 2.5. The average fall rate of celestial bodies similar to the Yushu meteoroid is 0.49 year^–1.