Successful and Failed Flux Tube Emergence in the Solar Interior
| Autor: | Vasilis Archontis, P. Syntelis, A. W. Hood |
|---|---|
| Přispěvatelé: | Science & Technology Facilities Council, University of St Andrews. Applied Mathematics |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Magnetohydrodynamics (MHD)
010504 meteorology & atmospheric sciences Field (physics) Astrophysics::High Energy Astrophysical Phenomena NDAS Flux FOS: Physical sciences 01 natural sciences 0103 physical sciences QB Astronomy Astrophysics::Solar and Stellar Astrophysics activity [Sun] 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Numerical [Methods] QB 0105 earth and related environmental sciences Physics Photosphere Condensed matter physics Flux tube interior [Sun] Astronomy and Astrophysics Radius Magnetic flux Magnetic field magnetic fields [Sun] Convection zone Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Physics::Space Physics |
| Popis: | We report on our three-dimensional (3D) magnetohydrodynamic (MHD) simulations of cylindrical weakly twisted flux tubes emerging from 18 Mm below the photosphere. We perform a parametric study, by varying the initial magnetic field strength ($B_0$), radius ($R$), twist ($\alpha)$ and length of the emerging part of the flux tube ($\lambda$) to investigate how these parameters affect the transfer of the magnetic field from the convection zone to the photosphere. We show that the efficiency of emergence at the photosphere (i.e. how strong the photospheric field will be in comparison to $B_0$) depends not only on the $B_0$ but also the morphology of the emerging field and the twist. We show that parameters such as $B_0$ and magnetic flux cannot alone determine whether a flux tube will emerge to the solar surface. For instance, high-$B_0$ (weak-$B_0$) fields may fail (succeed) to emerge at the photosphere, depending on their geometrical properties. We also show that the photospheric magnetic field strength can vary greatly for flux tubes with the same $B_0$ but different geometric properties. Moreover, in some cases we have found scaling laws, whereby the magnetic field strength scales with the local density as $B\propto \rho^\kappa$, where $\kappa \approx 1$ deeper in the convection zone and $\kappa Comment: 22 pages, 10 pages |
| Databáze: | OpenAIRE |
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