Variation of amplitude versus frequency

Amplitude and frequency of the resonance carry different types of information and behave differently. The amplitude is generally more variable than the frequency and primarily reflects the intensity of lightning activity — how much energy flows into the Earth-ionosphere cavity overall. The frequency of the peaks, on the other hand, is more stable and reflects rather the distribution and distance of the sources (see #45), not just their instantaneous strength.

This distinction has a practical consequence for interpretation. A sudden rise in amplitude can be attributed to an intensification of storm activity, whereas a shift in frequency points rather to a relocation of the center of gravity of the sources or to a change in the conductivity conditions of the cavity. Reading both quantities together — "stronger, or just closer?" — is therefore the basis of the inversion, in which the global lightning dynamics are reconstructed from the resonance parameters Satori 2024.