A global wave-driven magnetohydrodynamic solar model with a unified treatment of open and closed magnetic field topologies

Journal Article · Sun Dec 01 00:00:00 EST 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/778/2/176· OSTI ID:22341906

Oran, R.; Van der Holst, B.; Landi, E.; Jin, M.; Sokolov, I. V.

We describe, analyze, and validate the recently developed Alfvén Wave Solar Model, a three-dimensional global model starting from the top of the chromosphere and extending into interplanetary space (out to 1-2 AU). This model solves the extended, two-temperature magnetohydrodynamics equations coupled to a wave kinetic equation for low-frequency Alfvén waves. In this picture, heating and acceleration of the plasma are due to wave dissipation and to wave pressure gradients, respectively. The dissipation process is described by a fully developed turbulent cascade of counterpropagating waves. We adopt a unified approach for calculating the wave dissipation in both open and closed magnetic field lines, allowing for a self-consistent treatment in any magnetic topology. Wave dissipation is the only heating mechanism assumed in the model; no geometric heating functions are invoked. Electron heat conduction and radiative cooling are also included. We demonstrate that the large-scale, steady state (in the corotating frame) properties of the solar environment are reproduced, using three adjustable parameters: the Poynting flux of chromospheric Alfvén waves, the perpendicular correlation length of the turbulence, and a pseudoreflection coefficient. We compare model results for Carrington rotation 2063 (2007 November-December) with remote observations in the extreme-ultraviolet and X-ray ranges from the Solar Terrestrial Relations Observatory, Solar and Heliospheric Observatory, and Hinode spacecraft and with in situ measurements by Ulysses. The results are in good agreement with observations. This is the first global simulation that is simultaneously consistent with observations of both the thermal structure of the lower corona and the wind structure beyond Earth's orbit.

• OSTI ID: 22341906
• Journal Information: Astrophysical Journal, Vol. 778, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ACCELERATION
ALFVEN WAVES
CHROMOSPHERE
COMPUTERIZED SIMULATION
CORRELATIONS
EXTREME ULTRAVIOLET RADIATION
INTERPLANETARY SPACE
KINETIC EQUATIONS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
ORBITS
PLASMA
SOLAR WIND
STAR MODELS
SUN
THERMAL CONDUCTION
THREE-DIMENSIONAL CALCULATIONS
TURBULENCE
X RADIATION