Formation and primary heating of the solar corona: Theory and simulation

Abstract

An integrated Magneto-Fluid model, that accords full treatment to the Velocity fields associated with the directed plasma motion, is developed to investigate the dynamics of coronal structures. It is suggested that the interaction of the fluid and the magnetic aspects of plasma may be a crucial element in creating so much diversity in the solar atmosphere. It is shown that the structures which comprise the solar corona can be created by particle (plasma) flows observed near the Sun's surface -the primary heating of these structures is caused by the viscous dissipation of the flow kinetic energy.

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

“…As opposed to the fast initial heating, the second stage of additional, supporting heating may last for much longer time, at least for quasi-equilibrium structures. It needs to be emphasized that, in the approach of Mahajan et al (2001), Mahajan & Yoshida (1998), Yoshida & Mahajan (1999), and this paper, the flows are not extraneous to the structure but are an integral part of it-it is not the thermalization of an external flow that heats a preformed structure; the same flow provides the matter as well as the energy (eventually seen as heat) contained in the structure. This distinction is important.…”

“…The final result, fortunately, is the same: we obtain the set of double Beltrami-Bernoulli states (used in this paper) as the expression of self-organization. The system is amenable to the same treatment even for varying density as long as a polytropic equation of state is allowed (see Mahajan et al 2001). …”

“…Realistic transport processes are generally not included in the models that are often lower dimensional or steady state. Recently, in Goodman (2001) the necessity to account for transport processes was emphasized; it was also shown (based on estimates of energy fluxes required to heat the chromosphere and the corona) that the mechanism that transports mechanical energy from the convection zone to the chromosphere (to sustain its heating rate) could also supply the energy to heat the corona and accelerate the SW. A model for the general global dynamics that may operate in a given atmospheric region was proposed in Mahajan et al (1999Mahajan et al ( , 2001). …”

“…A systematic treatment of loop models that include flows was developed by Orlando, Peres, & Serio (1995a, 1995b and Mahajan et al (1999Mahajan et al ( , 2001 even though, at that time, there did not exist abundant evidence for a widespread occurrence of flows in the inner corona. More recently, a variety of investigators have begun to argue for the existence of flows in the solar atmosphere and have begun to speculate about the mechanisms of their creation.…”

“…We take this opportunity to remind the reader that the general unified model of Mahajan et al (2001) is based on the stipulation that the coronal structures are created from the evolution and reorganization of a relatively cold plasma flow emerging from the subcoronal regions and interacting with the ambient solar magnetic field. It is likely that this interaction may be the cause of the immense diversity of the observed coronal structures Mahajan & Yoshida 1998;Yoshida & Mahajan 1999).…”