Ion Charge States in a Time-Dependent Wave-Turbulence-Driven Model of the Solar Wind. (arXiv:1901.03748v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lionello_R/0/1/0/all/0/1">Roberto Lionello</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Downs_C/0/1/0/all/0/1">Cooper Downs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Linker_J/0/1/0/all/0/1">Jon A. Linker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mikic_Z/0/1/0/all/0/1">Zoran Mikić</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Raymond_J/0/1/0/all/0/1">John Raymond</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shen_C/0/1/0/all/0/1">Chengcai Shen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Velli_M/0/1/0/all/0/1">Marco Velli</a>
Ion fractional charge states, measured in situ in the heliosphere, depend on
the properties of the plasma in the inner corona. As the ions travel outward in
the solar wind and the electron density drops, the charge states remain
essentially unaltered or “frozen in”. Thus they can provide a powerful
constraint on heating models of the corona and acceleration of the solar wind.
We have implemented non-equilibrium ionization calculations into a 1D
wave-turbulence-driven (WTD) hydrodynamic solar wind model and compared modeled
charge states with the Ulysses 1994-5 in situ measurements. We have found that
modeled charge state ratios of $C^{6+}/C^{5+}$ and $O^{7+}/O^{6+}$, among
others, were too low compared with Ulysses measurements. However, a heuristic
reduction of the plasma flow speed has been able to bring the modeled results
in line with observations, though other ideas have been proposed to address
this discrepancy. We discuss implications of our results and the prospect of
including ion charge state calculations into our 3D MHD model of the inner
heliosphere.
Ion fractional charge states, measured in situ in the heliosphere, depend on
the properties of the plasma in the inner corona. As the ions travel outward in
the solar wind and the electron density drops, the charge states remain
essentially unaltered or “frozen in”. Thus they can provide a powerful
constraint on heating models of the corona and acceleration of the solar wind.
We have implemented non-equilibrium ionization calculations into a 1D
wave-turbulence-driven (WTD) hydrodynamic solar wind model and compared modeled
charge states with the Ulysses 1994-5 in situ measurements. We have found that
modeled charge state ratios of $C^{6+}/C^{5+}$ and $O^{7+}/O^{6+}$, among
others, were too low compared with Ulysses measurements. However, a heuristic
reduction of the plasma flow speed has been able to bring the modeled results
in line with observations, though other ideas have been proposed to address
this discrepancy. We discuss implications of our results and the prospect of
including ion charge state calculations into our 3D MHD model of the inner
heliosphere.
http://arxiv.org/icons/sfx.gif
