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The magnetic field structures of the global solar corona derived with a data-driven MHD simulation using time-series HMI vector-magnetic-field data

Presentation #407.07 in the session Understanding Solar Eruptions Using Data-driven Models and Multi-height Observations of the Solar Atmosphere I.

Published onOct 20, 2022
The magnetic field structures of the global solar corona derived with a data-driven MHD simulation using time-series HMI vector-magnetic-field data

The coronal magnetic field is one of the key objects in the field of solar physics and space weather. The large-scale magnetic field in the coronal streamers and coronal holes is a primary factor determining the structures of the solar wind and the entire heliosphere. The small-scale active-region magnetic field stores the free energy that will be released through eruptive events such as the solar flares and coronal mass ejections (CMEs). These potential-like large-scale magnetic features and nonpotential small-scale features are found in the corona simultaneously. The capability of reproducing the realistic potential and nonpotential magnetic features from the solar-surface observations is a critical element in studying the dynamics of the solar corona and solar wind.

We recently developed a time-dependent three-dimensional magnetohydrodynamics (MHD) simulation model for the global solar corona that can introduce the time-series SDO/HMI vector magnetic-field synoptic map data as the time-dependent three-component magnetic field boundary conditions. This MHD model uses an electric-field inversion method, named SEE3Po, that yields the boundary electric field vectors, curl of which matches the temporal variation of the specified solar-surface boundary vector magnetic field. The simulated magnetic field driven through the induction equation satisfies the divergence-free condition of the magnetic field and match the specified solar-surface boundary magnetic field vector data. The boundary treatment for the sub-Alfvenic solar surface boundary has a switch to determine whether all three component or only the radial component of the boundary magnetic field will follow the specified boundary data.

In this presentation, we demonstrate the current status of our new model. We will compare the time-relaxed quasi-steady states obtained with this new model and those with the conventional approach where only the radial component of the solar-surface magnetic field is introduced as the boundary value. We will also present full-data-driven time-dependent simulation with continuously varying solar-surface boundary magnetic field data for several Carrington rotation periods that numerically produces large-scale magnetic-field eruptions. These simulated magnetic-field structures are compared with the SDO/AIA coronal image data. Our solar wind MHD model is used to extend the time-dependent coronal/solar-wind solution to 1 AU for comparisons with the in-situ measurements of solar-wind MHD variables

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