Energy Transformation Mechanism in the Solar Atmosphere Associated with Magnetofluid Coupling: Explosive and Eruptive Events

Abstract

By modeling the closed field structures in the solar atmosphere by ``slowly'' evolving double Beltrami two-fluid equilibria (created by the interaction of the magnetic and velocity fields), the conditions for catastrophic transformations of the original state are derived. The analysis for predicting sudden changes is carried out through a set of algebraic equations obtained by relating the four characteristic parameters (two eigenvalues and two amplitudes) of the equilibrium to the macroscopic constants of motion (helicities and energy). It is shown that a catastrophic loss of equilibrium occurs when the macro scale of a closed structure, interacting with its local surroundings, decreases below a critical value; the catastrophe is possible only if the total energy of the structure (for given helicities) also exceeds a well-defined threshold. It is further shown that at the transition much of the magnetic energy of the original state is converted to the flow kinetic energy.