Turbulent heating of coronal active regions

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Magnetohydrodynamic turbulence has been proposed as a mechanism for the heating of coronal active regions, and has therefore been actively investigated in recent years. According to this scenario, a turbulent regime is driven by footpoint motions. The energy being pumped this way into active region...

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Autores principales:	Gómez, D.O., Dmitruk, P.
Formato:	Artículo publishedVersion
Publicado:	2007
Materias:	Coronal heating Mhd turbulence Nanoflares Solar corona
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_17439213_v3_nS247_p269_Gomez http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_17439213_v3_nS247_p269_Gomez_oai
Aporte de:	Repositorio Digital de la Universidad de Buenos Aires (UBA) de Universidad de Buenos Aires

id	I28-R145-paper_17439213_v3_nS247_p269_Gomez_oai
record_format	dspace
spelling	I28-R145-paper_17439213_v3_nS247_p269_Gomez_oai2020-10-19 Gómez, D.O. Dmitruk, P. 2007 Magnetohydrodynamic turbulence has been proposed as a mechanism for the heating of coronal active regions, and has therefore been actively investigated in recent years. According to this scenario, a turbulent regime is driven by footpoint motions. The energy being pumped this way into active region loops, is efficiently transferred to small scales due to a direct energy cascade. The ensuing generation of fine scale structures, which is a natural outcome of turbulent regimes, helps to enhance the dissipation of either waves or DC currents. We present an updated overview of recent results on turbulent coronal heating. To illustrate this theoretical scenario, we simulate the internal dynamics of a coronal loop within the reduced MHD approximation. The application of a stationary velocity field at the photospheric boundary leads to a turbulent stationary regime after several photospheric turnover times. This regime is characterized by a broadband power spectrum and energy dissipation rate levels compatible with the heating requirements of active region loops. Also, the energy dissipation rate displays a complex superposition of impulsive events, which we associate to the so-called nanoflares. A statistical analysis yields a power law distribution as a function of their energies, which is consistent with those obtained from observations. We also study the distributions of peak dissipation rate and duration of these events. © 2008 International Astronomical Union. Fil:Gómez, D.O. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Dmitruk, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. application/pdf http://hdl.handle.net/20.500.12110/paper_17439213_v3_nS247_p269_Gomez info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar Proc. Int. Astron. Union 2007;3(S247):269-278 Coronal heating Mhd turbulence Nanoflares Solar corona Turbulent heating of coronal active regions info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_17439213_v3_nS247_p269_Gomez_oai
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-145
collection	Repositorio Digital de la Universidad de Buenos Aires (UBA)
topic	Coronal heating Mhd turbulence Nanoflares Solar corona
spellingShingle	Coronal heating Mhd turbulence Nanoflares Solar corona Gómez, D.O. Dmitruk, P. Turbulent heating of coronal active regions
topic_facet	Coronal heating Mhd turbulence Nanoflares Solar corona
description	Magnetohydrodynamic turbulence has been proposed as a mechanism for the heating of coronal active regions, and has therefore been actively investigated in recent years. According to this scenario, a turbulent regime is driven by footpoint motions. The energy being pumped this way into active region loops, is efficiently transferred to small scales due to a direct energy cascade. The ensuing generation of fine scale structures, which is a natural outcome of turbulent regimes, helps to enhance the dissipation of either waves or DC currents. We present an updated overview of recent results on turbulent coronal heating. To illustrate this theoretical scenario, we simulate the internal dynamics of a coronal loop within the reduced MHD approximation. The application of a stationary velocity field at the photospheric boundary leads to a turbulent stationary regime after several photospheric turnover times. This regime is characterized by a broadband power spectrum and energy dissipation rate levels compatible with the heating requirements of active region loops. Also, the energy dissipation rate displays a complex superposition of impulsive events, which we associate to the so-called nanoflares. A statistical analysis yields a power law distribution as a function of their energies, which is consistent with those obtained from observations. We also study the distributions of peak dissipation rate and duration of these events. © 2008 International Astronomical Union.
format	Artículo Artículo publishedVersion
author	Gómez, D.O. Dmitruk, P.
author_facet	Gómez, D.O. Dmitruk, P.
author_sort	Gómez, D.O.
title	Turbulent heating of coronal active regions
title_short	Turbulent heating of coronal active regions
title_full	Turbulent heating of coronal active regions
title_fullStr	Turbulent heating of coronal active regions
title_full_unstemmed	Turbulent heating of coronal active regions
title_sort	turbulent heating of coronal active regions
publishDate	2007
url	http://hdl.handle.net/20.500.12110/paper_17439213_v3_nS247_p269_Gomez http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=artiaex&d=paper_17439213_v3_nS247_p269_Gomez_oai
work_keys_str_mv	AT gomezdo turbulentheatingofcoronalactiveregions AT dmitrukp turbulentheatingofcoronalactiveregions
_version_	1766026798640922624

Turbulent heating of coronal active regions

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