Threaded-Field-Lines Model for the Low Solar Corona Powered by the Alfven Wave Turbulence. (arXiv:1609.04379v3 [astro-ph.SR] UPDATED)

Threaded-Field-Lines Model for the Low Solar Corona Powered by the Alfven Wave Turbulence. (arXiv:1609.04379v3 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Sokolov_I/0/1/0/all/0/1">Igor V. Sokolov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Holst_B/0/1/0/all/0/1">Bart van der Holst</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Manchester_W/0/1/0/all/0/1">Ward B. Manchester</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ozturk_D/0/1/0/all/0/1">Doga Can Su Ozturk</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Szente_J/0/1/0/all/0/1">Judit Szente</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Taktakishvili_A/0/1/0/all/0/1">Aleksandre Taktakishvili</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toth_G/0/1/0/all/0/1">Gabor T&#xf3;th</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jin_M/0/1/0/all/0/1">Meng Jin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gombosi_T/0/1/0/all/0/1">Tamas I. Gombosi</a>

We present an updated global model of the solar corona, including the
transition region. We simulate the realistic tree-dimensional (3D) magnetic
field using the data from the photospheric magnetic field measurements and
assume the magnetohydrodynamic (MHD) Alfv’en wave turbulence and its
non-linear dissipation to be the only source for heating the coronal plasma and
driving the solar wind. In closed field regions the dissipation efficiency in a
balanced turbulence is enhanced. In the coronal holes we account for a
reflection of the outward propagating waves, which is accompanied by generation
of weaker counter-propagating waves. The non-linear cascade rate degrades in
strongly imbalanced turbulence, thus resulting in colder coronal holes.

The distinctive feature of the presented model is the description of the low
corona as almost-steady-state low-beta plasma motion and heat flux transfer
along the magnetic field lines. We trace the magnetic field lines through each
grid point of the lower boundary of the global corona model, chosen at some
heliocentric distance, $R=R_{b}sim1.1 R_odot$ well above the transition
region. One can readily solve the plasma parameters along the magnetic field
line from 1D equations for the plasma motion and heat transport together with
the Alfv’en wave propagation, which adequately describe physics within the
heliocentric distances range, $R_{odot}<R<R_{b}$, in the low solar corona. By
interfacing this threaded-field-lines model with the full MHD global corona
model at $r=R_{b}$, we find the global solution and achieve a
faster-than-real-time performance of the model on $sim200$ cores.

We present an updated global model of the solar corona, including the
transition region. We simulate the realistic tree-dimensional (3D) magnetic
field using the data from the photospheric magnetic field measurements and
assume the magnetohydrodynamic (MHD) Alfv’en wave turbulence and its
non-linear dissipation to be the only source for heating the coronal plasma and
driving the solar wind. In closed field regions the dissipation efficiency in a
balanced turbulence is enhanced. In the coronal holes we account for a
reflection of the outward propagating waves, which is accompanied by generation
of weaker counter-propagating waves. The non-linear cascade rate degrades in
strongly imbalanced turbulence, thus resulting in colder coronal holes.

The distinctive feature of the presented model is the description of the low
corona as almost-steady-state low-beta plasma motion and heat flux transfer
along the magnetic field lines. We trace the magnetic field lines through each
grid point of the lower boundary of the global corona model, chosen at some
heliocentric distance, $R=R_{b}sim1.1 R_odot$ well above the transition
region. One can readily solve the plasma parameters along the magnetic field
line from 1D equations for the plasma motion and heat transport together with
the Alfv’en wave propagation, which adequately describe physics within the
heliocentric distances range, $R_{odot}<R<R_{b}$, in the low solar corona. By
interfacing this threaded-field-lines model with the full MHD global corona
model at $r=R_{b}$, we find the global solution and achieve a
faster-than-real-time performance of the model on $sim200$ cores.

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