Daily frequency range (DFR) and the size of storm regions

The daily frequency range (DFR) is the difference between the highest and lowest value of the peak frequency during the day, that is, \text{DFR} = f_\text{max} - f_\text{min}. This quantity is not merely a technical detail — it carries information about the average size (extent) of the storm regions that contribute to the resonance during the day Satori 2024.

The connection arises from the way the extent of the source region and its movement during the day modulate the effective source-observer distance (see #45) and thereby the daily swing of the observed frequency. The DFR thus serves as a diagnostic indicator: from the magnitude of the daily frequency range one can infer the characteristic spatial extent of the active storm centers Satori 2024.