ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL

Cargill, P J; Bradshaw, S J

doi:10.1088/0004-637X/752/2/161

Title: ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL

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Abstract

This paper develops the zero-dimensional (0D) hydrodynamic coronal loop model 'Enthalpy-based Thermal Evolution of Loops' (EBTEL) proposed by Klimchuk et al., which studies the plasma response to evolving coronal heating, especially impulsive heating events. The basis of EBTEL is the modeling of mass exchange between the corona and transition region (TR) and chromosphere in response to heating variations, with the key parameter being the ratio of the TR to coronal radiation. We develop new models for this parameter that now include gravitational stratification and a physically motivated approach to radiative cooling. A number of examples are presented, including nanoflares in short and long loops, and a small flare. The new features in EBTEL are important for accurate tracking of, in particular, the density. The 0D results are compared to a 1D hydro code (Hydrad) with generally good agreement. EBTEL is suitable for general use as a tool for (1) quick-look results of loop evolution in response to a given heating function, (2) extensive parameter surveys, and (3) situations where the modeling of hundreds or thousands of elemental loops is needed. A single run takes a few seconds on a contemporary laptop.

Authors:

Cargill, P J ^[1]; Bradshaw, S J ^[2]

Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)
Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States)

Publication Date:: Wed Jun 20 00:00:00 EDT 2012

OSTI Identifier:: 22036986

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 752; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; CHROMOSPHERE; COMPUTERIZED SIMULATION; DENSITY; ENTHALPY; HEATING; MASS; PLASMA; RADIATIVE COOLING; SOLAR CORONA; SOLAR FLARES; STAR EVOLUTION; STRATIFICATION; SUN; VARIATIONS

Citation Formats


                    Cargill, P J, Bradshaw, S J, and Klimchuk, J. A., E-mail: p.cargill@imperial.ac.uk. ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL.  United States: N. p., 2012. 
        Web.  doi:10.1088/0004-637X/752/2/161.

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                    Cargill, P J, Bradshaw, S J, & Klimchuk, J. A., E-mail: p.cargill@imperial.ac.uk. ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL.  United States.  https://doi.org/10.1088/0004-637X/752/2/161

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                    Cargill, P J, Bradshaw, S J, and Klimchuk, J. A., E-mail: p.cargill@imperial.ac.uk. 2012.  
        "ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL".  United States.  https://doi.org/10.1088/0004-637X/752/2/161.

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@article{osti_22036986,

  title        = {ENTHALPY-BASED THERMAL EVOLUTION OF LOOPS. II. IMPROVEMENTS TO THE MODEL},

  author       = {Cargill, P J and Bradshaw, S J and Klimchuk, J. A., E-mail: p.cargill@imperial.ac.uk},

  abstractNote = {This paper develops the zero-dimensional (0D) hydrodynamic coronal loop model 'Enthalpy-based Thermal Evolution of Loops' (EBTEL) proposed by Klimchuk et al., which studies the plasma response to evolving coronal heating, especially impulsive heating events. The basis of EBTEL is the modeling of mass exchange between the corona and transition region (TR) and chromosphere in response to heating variations, with the key parameter being the ratio of the TR to coronal radiation. We develop new models for this parameter that now include gravitational stratification and a physically motivated approach to radiative cooling. A number of examples are presented, including nanoflares in short and long loops, and a small flare. The new features in EBTEL are important for accurate tracking of, in particular, the density. The 0D results are compared to a 1D hydro code (Hydrad) with generally good agreement. EBTEL is suitable for general use as a tool for (1) quick-look results of loop evolution in response to a given heating function, (2) extensive parameter surveys, and (3) situations where the modeling of hundreds or thousands of elemental loops is needed. A single run takes a few seconds on a contemporary laptop.},

  doi          = {10.1088/0004-637X/752/2/161},

  url          = {https://www.osti.gov/biblio/22036986},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 2,

  volume       = 752,

  place        = {United States},

  year         = {Wed Jun 20 00:00:00 EDT 2012},

  month        = {Wed Jun 20 00:00:00 EDT 2012}

}

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