Mechanisms of gas formation in eruptive clouds

Abstract

Continuous monitoring of electromagnetic radiation of natural origin in VLF range (3-30 kHz) allowed us to collect a long-term data base of thunderstorm activity in Kamchatka peninsula. The collected data base also includes lightning cells determined by «dirty thunderstorms» generated during volcanic explosive eruptions. The earlier analysis showed that two-stage scenario of development is typical for all «dirty thunderstorms». The first stage is accompanied by eruptive column formation and depends on eruption power and ash cloud height. The second stage, depending on eruption power and on eruptive cloud interaction during its propagation with meteorological clouds, is associated with eruptive cloud formation and propagation. The paper shows the mechanism of gas formation in eruptive clouds. It explains the sequence of two stages.