The Sun as a MHD generator: application of a new heating mechanism for the coronal loops and closed magnetic structures

Abstract

We investigate a possibility of heating of the loops and other closed magnetic structures in active regions of the solar corona by the flow of solar wind (plus other flows that may be present) across the magnetic field lines (that are perpendicular to the flow), in a similar manner as a conventional MHD generator works. A simple model is formulated which allows to calculate the typical currents generated by this mechanism. This enables to make a judgement whether the loops in solar active regions can be heated by the proposed mechanism through the associated Ohmic dissipation. It is shown that even if the heating region width is of the order of a few proton Larmor radii (this effectively means that a loop is represented by {\it nano-threads}, by analogy with the nano-flare coronal heating mechanism, with width of a few proton Larmor radii) and the plasma flow speed is 50 km s${}^{-1}$ then only about 1% of the heating requirement of coronal loops could be met under this conjecture. Other implications of the model, such as a predicted spatial heat distribution along the loop as well as application of the model to the other places e.g. chromosphere and corotating interaction region structures in the solar wind are discussed.

final, accepted in Astron. Astrophys. version

References in corpus (7)

• Plasmoid-Induced-Reconnection and Fractal Reconnection
• Particle-In-Cell simulations of circularly polarised Alfvén wave phase mixing: a new mechanism for electron acceleration in collisionless plasmas
• A Three Dimensional Magnetohydrodynamic Pulse in a Transversely Inhomogeneous Medium
• A Strongly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium
• A Weakly Nonlinear Alfvenic Pulse in a Transversely Inhomogeneous Medium
• Phase mixing of a three dimensional magnetohydrodynamic pulse
• Phase mixing of shear Alfven waves as a new mechanism for electron acceleration in collisionless, kinetic plasmas

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• Heating of solar chromosphere by electromagnetic wave absorption in a plasma slab model