GNGTS 2019 - Atti del 38° Convegno Nazionale

296 GNGTS 2019 S essione 2.1 Fig. 2 - The air ion counting during a thunderstorms at the Fermo Station shows that charge density inversions are measured; they occur during the intense stage of thunderstorms here indicated by vertical lines of the Electrodynamic Pluviometer in the middle, and violet color of the vertical electrode at the bottom. Fig. 3 - Charge density measured at Fermo Station contemporary to an electric oscillation detection; a charge density inversion is detected at the same time of the measured oscillation; However, further charge density inversions are revealed when electric oscillations does not appear.