Schumann resonances This morning.

Above the frequencies of the findamentl F1, and harmonics F2,F3,F4 of Schumann resonances on earth. we see a slow increase of the frequency values, but their corresponding amplitudes are low as shown below. It all seems quiet!

[This global electromagnetic resonance phenomenon is named after physicist Winfried Otto Schumann who predicted it mathematically in 1952. Schumann resonances occur because the space between the surface of the Earth and the conductive ionosphere acts as a closed waveguide. The limited dimensions of the Earth cause this waveguide to act as a resonant cavity for electromagnetic waves in the ELF band. The cavity is naturally excited by electric currents in lightning. Schumann resonances are the principal background in the part of the electromagnetic spectrum^[1] from 3 Hz through 60 Hz,^[2] and appear as distinct peaks at extremely low frequencies (ELF) around 7.83 Hz (fundamental),^[3] 14.3, 20.8, 27.3 and 33.8 Hz]