AbstractThe dynamics of the solar corona as well as its very existence are due to the dynamics of plasmas and magnetic fields which, at the global scales of coronal loops, prominences and helmet streamers may be described by magnetohydrodynamics. Here, we discuss the importance and role of nonlinear interactions in the heating of the solar corona, which relies on the transfer, storage and dissipation of the mechanical energy present in photospheric motion [Einaudi, G., Velli, M., Phys. Plasmas 6, 4146, 1999]. Nonlinear interactions including the coupling of coronal fields to the motions and emerging flux through the photosphere determine both the rate of heating and the topology of coronal magnetic fields.We present the first results of a 3D reduced MHD simulation that models the small-scale magnetic activity of coronal flux tubes. The equations are solved inside a box of dimensions l×l×L (axial direction), with an aspect ratio L/l of the order of 10. The box is initially threaded by a constant sinusoidal velocity field at one base (corresponding to one photospheric footpoint of the loop), of amplitude 1km/s, (the axial Alfvén speed is about 1000km/s), whereas the other footpoint is anchored, i.e., no photospheric motions are present. In the transverse directions, periodicity is assumed. Our numerical calculations show that the magnetic field lines change their topology continuously and often reconnect at small scales, forming typical coronal loop-like structures. Energy release events which provide a steady supply of energy are associated with the reconnection.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Nonlinear interactions in coronal heating


    Contributors:
    Rappazzo, A.F. (author) / Dahlburg, R.B. (author) / Einaudi, G. (author) / Velli, M. (author)

    Published in:

    Advances in Space Research ; 37 , 7 ; 1335-1341


    Publication date :

    2005-12-20


    Size :

    7 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Nonlinear interactions in coronal heating

    Rappazzo, A. F. / Dahlburg, R. B. / Einaudi, G. et al. | British Library Conference Proceedings | 2006


    Nonlinear interactions in coronal heating

    Rappazzo, A.F. | Online Contents | 2006


    Coronal Heating (Abstract)

    Axford, W. I. / McKenzie, J. F. / The Committee on Space Research | British Library Conference Proceedings | 2002


    Coronal heating mechanisms

    Serio, Salvatore | Elsevier | 1982


    Coronal heating - Numerical experiments

    Galsgaard, K. | British Library Conference Proceedings | 2006