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An MHD simulation model of time‐dependent global solar corona with temporally varying solar‐surface magnetic field maps
Author(s) -
Hayashi K.
Publication year - 2013
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2013ja018991
Subject(s) - corona (planetary geology) , physics , interplanetary magnetic field , dipole model of the earth's magnetic field , solar wind , magnetohydrodynamics , coronal hole , coronal mass ejection , nanoflares , coronal loop , computational physics , magnetic field , geophysics , quantum mechanics , astrobiology , venus
We present a model of a time‐dependent three‐dimensional magnetohydrodynamics simulation of the sub‐Alfvenic solar corona and super‐Alfvenic solar wind with temporally varying solar‐surface boundary magnetic field data. To (i) accommodate observational data with a somewhat arbitrarily evolving solar photospheric magnetic field as the boundary value and (ii) keep the divergence‐free condition, we developed a boundary model, here named Confined Differential Potential Field model, that calculates the horizontal components of the magnetic field, from changes in the vertical component, as a potential field confined in a thin shell. The projected normal characteristic method robustly simulates the solar corona and solar wind, in response to the temporal variation of the boundary B r . We conduct test MHD simulations for two periods, from Carrington Rotation number 2009 to 2010 and from Carrington Rotation 2074 to 2075 at solar maximum and minimum of Cycle 23, respectively. We obtained several coronal features that a fixed boundary condition cannot yield, such as twisted magnetic field lines at the lower corona and the transition from an open‐field coronal hole to a closed‐field streamer. We also obtained slight improvements of the interplanetary magnetic field, including the latitudinal component, at Earth.