Hostname: page-component-8448b6f56d-jr42d Total loading time: 0 Render date: 2024-04-20T01:47:39.642Z Has data issue: false hasContentIssue false
  • English
  • Français

Energy balance and cascade in MHD turbulence in the solar corona

Published online by Cambridge University Press:  01 September 2008

Francesco Malara ,
Giuseppina Nigro  and
Pierluigi Veltri
Francesco Malara
Affiliation:
Dipartimento di Fisica, Università della Calabria, via P. Bucci, I-87036, Rende (CS), Italy email: malara@fis.unical.it, nigro@fis.unical.it, veltri@fis.unical.it
Giuseppina Nigro
Affiliation:
Dipartimento di Fisica, Università della Calabria, via P. Bucci, I-87036, Rende (CS), Italy email: malara@fis.unical.it, nigro@fis.unical.it, veltri@fis.unical.it
Pierluigi Veltri
Affiliation:
Dipartimento di Fisica, Università della Calabria, via P. Bucci, I-87036, Rende (CS), Italy email: malara@fis.unical.it, nigro@fis.unical.it, veltri@fis.unical.it
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The dynamics of fluctuations in a closed coronal structure is regulated both by resonance with motions at bases that stores energy in the structure in form of discrete eigenmodes, and by nonlinear couplings that move this energy along the spectrum to smaller scales. The energy balance is evaluated both analytically and, numerically, using an hybrid shell model. The input energy flux is independent of nonlinear effects and is determined by slow (DC) perturbations. Coherent eigenmode couplings determine the nonlinear energy flux and, consequently, the level of fluctuations at large scales. The estimated velocity fluctuation level is in agreement with measures of nonthermal velocity in corona. The resulting turbulence spectrum contains both a pre-inertial range where coherent interactions dominate, and a standard inertial range where the turbulence behaves as in an unbounded system.

Keywords

Sun: corona(magnetohydrodynamics:) MHDturbulencewaves
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 4 , Symposium S257: Universal Heliophysical Processes , September 2008 , pp. 543 - 553
Copyright
Copyright © International Astronomical Union 2009

References

Boffetta, G., Carbone, V., Giuliani, P., Veltri, P., & Vulpiani, A., 1999, Phys. Rev. Lett., 83, 4662CrossRefGoogle Scholar
Buchlin, E. & Velli, M., 2007, ApJ, 662, 701CrossRefGoogle Scholar
Davila, J. M. 1987, ApJ, 317, 514CrossRefGoogle Scholar
Dmitruk, P. & Gomez, D. O., 1997, ApJ, 484, L83CrossRefGoogle Scholar
Einaudi, G., Velli, M., Politano, H., & Pouquet, A., 1996, ApJ, 457, L113CrossRefGoogle Scholar
Giuliani, P. & Carbone, V., 1998, Europhys. Lett., 43, 527CrossRefGoogle Scholar
Heyvaerts, J. & Priest, E. R., 1983, Astron. Astrophys., 117, 220Google Scholar
Ionson, J. A., 1982, ApJ, 254, 318CrossRefGoogle Scholar
Milano, L., Gomez, D. O., & Martens, P. C. H., 1997, ApJ, 490, 442CrossRefGoogle Scholar
Nigro, G., Malara, F., Carbone, V., Veltri, P. 2004, Phys. Rev. Lett., 92, 194501, 1.CrossRefGoogle Scholar
Nigro, G., Malara, F., & Veltri, P. 2008, ApJ, 685, 606CrossRefGoogle Scholar
Petkaki, P., Malara, F., & Veltri, P. 1998, ApJ, 500, 483CrossRefGoogle Scholar
Strauss, H. 1976, Phys. Fluids, 19, 134CrossRefGoogle Scholar
Sturrock, P. A. & Uchida, Y. 1981, ApJ, 246, 331CrossRefGoogle Scholar
Withbroe, G. L., 1988, ApJ, 325, 442CrossRefGoogle Scholar
Warren, H. P., Mariska, J. T., Wilhelm, K., & Lamaire, P. 1997, ApJ, 484, L91CrossRefGoogle Scholar