[1] The ELF measurements in Russian observatories Lovozero (the Kola Peninsula) and Lekhta (Karelija) during the solar proton event of 14 July 2000 show the decrease of frequencies of the first and second Schumann resonance modes of $0.4 Hz and the increase of the first-mode bandwidth from 0.8 to 1.5 Hz. The solar X-ray burst, preceding the proton precipitation, is accompanied by the increase of the first-mode frequency. Approximate formulas for frequencies and qualities of the two first modes are found for a two-layer model of the Schumann resonator (SR). The changes of the SR parameters are a response of the Earth-ionosphere resonator to large-scale disturbances of the polar ionosphere.

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[1] Variations of the first mode Schumann resonance frequency in the Kola Peninsula and of the first and second mode frequencies in Kamchatka during seven days of MarchApril 2001, when the intensive solar X-ray bursts occurred, are studied with 5 min averaging. All X-ray bursts were accompanied by $0.2 Hz increase in the first mode frequency, at least in one of the magnetic components. Duration of the increases coincided with that of the bursts. For the second mode the increase (in average by $0.3 Hz) was registered in most events, when the ELF noise level was not very high.

Abstract. The variations of the ®rst mode of Schumann resonance are analyzed using data from Kola peninsula stations during the solar proton event of 6 November 1997. On this day the intensive¯ux of energetic protons on GOES-8 and the 10% increase of the count rate of the neutron monitor in Apatity between 1220 and 2000 UT were preceded by a solar X-ray burst at 1155 UT. This burst was accompanied by a simultaneous increase of the Schumann frequency by 3.5%, and the relativistic proton¯ux increase was accompanied by 1% frequency decrease. These e ects are explained by changes of the height and dielectric permeability of the Earth-ionosphere cavity.

Abstract. The variations of the ®rst mode of Schumann resonance are analyzed using data from Kola peninsula stations during the solar proton event of 6 November 1997. On this day the intensive¯ux of energetic protons on GOES-8 and the 10% increase of the count rate of the neutron monitor in Apatity between 1220 and 2000 UT were preceded by a solar X-ray burst at 1155 UT. This burst was accompanied by a simultaneous increase of the Schumann frequency by 3.5%, and the relativistic proton¯ux increase was accompanied by 1% frequency decrease. These eects are explained by changes of the height and dielectric permeability of the Earth-ionosphere cavity.