An optimization principle for computing stationary MHD equilibria with solar wind flow

Thomas Wiegelmann; Thomas Neukirch; Dieter Nickeler; Iulia Chifu

doi:10.1007/s11207-020-01719-8

An optimization principle for computing stationary MHD equilibria with solar wind flow

Thomas Wiegelmann^*, Thomas Neukirch, Dieter Nickeler, Iulia Chifu

^*Corresponding author for this work

Applied Mathematics

Research output: Contribution to journal › Article › peer-review

Abstract

In this work we describe a numerical optimization method for computing stationary MHD-equilibria. The newly developed code is based on a nonlinearforce-free optimization principle. We apply our code to model the solar corona using synoptic vector magnetograms as boundary condition. Below about two solar radii the plasma β and Alfvén Mach number M_A are small and the magnetic field configuration of stationary MHD is basically identical to a nonlinear force-free field, whereas higher up in the corona (where β and M_A are above unity) plasma and flow effects become important and stationary MHD and force-free configuration deviate significantly. The new method allows the reconstruction of the coronal magnetic field further outwards than with potential field, nonlinear force-free or magneto-static models. This way the model might help to provide the magnetic connectivity for joint observations of remote sensing and in-situ instruments on Solar Orbiter and Parker Solar Probe.

Original language	English
Article number	145
Number of pages	14
Journal	Solar Physics
Volume	295
Issue number	10
Early online date	29 Oct 2020
DOIs	https://doi.org/10.1007/s11207-020-01719-8
Publication status	Published - Oct 2020

Keywords

Magnetic fields, corona
Magnetic fields, models
Magnetohydrodynamics
Velocity fields, solar wind

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Wiegelmann-2020_An_Optimization_Principle_SolarPhys-145-CCBY
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Final published version, 2.17 MBLicence: CC BY

https://arxiv.org/abs/2010.02945

Solar and Magnetospheric: Solar and Magnetospheric Magnetohydrodynamics and Plasmas: Theory and Application
Hood, A. W. (PI), Archontis, V. (CoI), De Moortel, I. (CoI), Mackay, D. H. (CoI), Neukirch, T. (CoI), Parnell, C. E. (CoI) & Wright, A. N. (CoI)
Science & Technology Facilities Council
1/04/19 → 31/03/22
Project: Standard

Cite this

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title = "An optimization principle for computing stationary MHD equilibria with solar wind flow",

abstract = "In this work we describe a numerical optimization method for computing stationary MHD-equilibria. The newly developed code is based on a nonlinearforce-free optimization principle. We apply our code to model the solar corona using synoptic vector magnetograms as boundary condition. Below about two solar radii the plasma β and Alfv{\'e}n Mach number MA are small and the magnetic field configuration of stationary MHD is basically identical to a nonlinear force-free field, whereas higher up in the corona (where β and MA are above unity) plasma and flow effects become important and stationary MHD and force-free configuration deviate significantly. The new method allows the reconstruction of the coronal magnetic field further outwards than with potential field, nonlinear force-free or magneto-static models. This way the model might help to provide the magnetic connectivity for joint observations of remote sensing and in-situ instruments on Solar Orbiter and Parker Solar Probe.",

keywords = "Magnetic fields, corona, Magnetic fields, models, Magnetohydrodynamics, Velocity fields, solar wind",

author = "Thomas Wiegelmann and Thomas Neukirch and Dieter Nickeler and Iulia Chifu",

note = "TW acknowledges financial support by DLR-grant 50 OC 1701 and DFG-grant WI 3211/5-1. TN acknowledges financial support by the UK{\textquoteright}s Science and Technology Facilities Council (STFC) via Consolidated Grant ST/S000402/1. The Astronomical Institute of the Czech Academy of Sciences is supported by the project RVO:67985815. IC acknowledges funding by DFG-grant WI 3211/5-1. ",

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doi = "10.1007/s11207-020-01719-8",

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T1 - An optimization principle for computing stationary MHD equilibria with solar wind flow

AU - Wiegelmann, Thomas

AU - Neukirch, Thomas

AU - Nickeler, Dieter

AU - Chifu, Iulia

N1 - TW acknowledges financial support by DLR-grant 50 OC 1701 and DFG-grant WI 3211/5-1. TN acknowledges financial support by the UK’s Science and Technology Facilities Council (STFC) via Consolidated Grant ST/S000402/1. The Astronomical Institute of the Czech Academy of Sciences is supported by the project RVO:67985815. IC acknowledges funding by DFG-grant WI 3211/5-1.

PY - 2020/10

Y1 - 2020/10

N2 - In this work we describe a numerical optimization method for computing stationary MHD-equilibria. The newly developed code is based on a nonlinearforce-free optimization principle. We apply our code to model the solar corona using synoptic vector magnetograms as boundary condition. Below about two solar radii the plasma β and Alfvén Mach number MA are small and the magnetic field configuration of stationary MHD is basically identical to a nonlinear force-free field, whereas higher up in the corona (where β and MA are above unity) plasma and flow effects become important and stationary MHD and force-free configuration deviate significantly. The new method allows the reconstruction of the coronal magnetic field further outwards than with potential field, nonlinear force-free or magneto-static models. This way the model might help to provide the magnetic connectivity for joint observations of remote sensing and in-situ instruments on Solar Orbiter and Parker Solar Probe.

AB - In this work we describe a numerical optimization method for computing stationary MHD-equilibria. The newly developed code is based on a nonlinearforce-free optimization principle. We apply our code to model the solar corona using synoptic vector magnetograms as boundary condition. Below about two solar radii the plasma β and Alfvén Mach number MA are small and the magnetic field configuration of stationary MHD is basically identical to a nonlinear force-free field, whereas higher up in the corona (where β and MA are above unity) plasma and flow effects become important and stationary MHD and force-free configuration deviate significantly. The new method allows the reconstruction of the coronal magnetic field further outwards than with potential field, nonlinear force-free or magneto-static models. This way the model might help to provide the magnetic connectivity for joint observations of remote sensing and in-situ instruments on Solar Orbiter and Parker Solar Probe.

KW - Magnetic fields, corona

KW - Magnetic fields, models

KW - Magnetohydrodynamics

KW - Velocity fields, solar wind

U2 - 10.1007/s11207-020-01719-8

DO - 10.1007/s11207-020-01719-8

M3 - Article

SN - 0038-0938

VL - 295

JO - Solar Physics

JF - Solar Physics

IS - 10

M1 - 145

ER -

An optimization principle for computing stationary MHD equilibria with solar wind flow

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Keywords

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Solar and Magnetospheric: Solar and Magnetospheric Magnetohydrodynamics and Plasmas: Theory and Application

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