POLARIZATION OF THE SCHUMANN RESONANCE HORIZONTAL MAGNETIC FIELD IN THE ANISOTROPIC EARTH-IONOSPHERE CAVITY

摘要

We present the polarization characteristics of the horizontal magnetic field component in the Schumann resonance band (4-40 Hz). The resonance is observed in the spherical Earth-ionosphere cavity driven by emission of the global thunderstorm activity. The upper boundary of the cavity in formed by the anisotropic plasma of the lower ionosphere, which is found in the geomagnetic field. The plasma anisotropy may cause a peculiar behavior of the resonance electromagnetic field. We treat the formal electromagnetic problem first and compute the expected impact of Earth's magnetic field on the polarization of resonance waves. The simplest model is used of a single compact equatorial thunderstorm center that circles the planet during the day. In the second part of the report, we present durable experimental data on the polarization of the Schumann resonance fields. Finally, we compare the data computed with the experimental results and demonstrate their exceptional consistency. A conclusion is made that elliptic polarization of natural ELF radio signal around peak frequencies proves that there exists the splitting of the Schumann resonance lines caused by the geomagnetic field.