Daytime geomagnetic pulsations accompanying sudden impulse of solar wind




ion-cyclotron wave, ultra-low frequency burst, charged particle flux, dynamic spectrum


This article describes in detail ultra-low frequency (ULF) burst of oscillations, which was observed on April 23, 2002 immediately after a sudden geomagnetic pulse. The source of the pulse was a sharp inhomogeneity of the solar wind, which was acting on the magnetosphere, accompanied by a jump in dynamic pressure. We used simultaneous measurements of the magnetic and electric fields, as well as plasma parameters from the Polar satellite and data from induction magnetometers at the Mondy and Borok observatories. Polar spacecraft and obs. Mondy were near the noon meridian at the time of the burst recording. Comparing the time regime of dynamic spectra of oscillations on Earth and in space with on-board records of variations in the intensity and anisotropy of charged particles, we assumed that the burst of ion-cyclotron waves was excited as a result of the effect of a sudden impulse on the magnetosphere. The packet of these waves ran along the field line to the conjugate point in the ionosphere, and then propagated along the ionospheric waveguide. These conclusions are compared with another event on June 28, 1999, also associated with a sudden impulse. In this case, the form of the dynamic spectrum of the burst is characteristic not of ion-cyclotron, but of fast magnetosonic waves. Possible burst generation mechanisms of both types are discussed.


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How to Cite

Battuulai, T., Potapov, A., & Baatar, N. (2022). Daytime geomagnetic pulsations accompanying sudden impulse of solar wind. Proceedings of the Mongolian Academy of Sciences, 62(02), 1–14.