A data-driven MHD model of the global solar corona within Multi-Scale Fluid-Kinetic Simulation Suite (MS-FLUKSS)

Mehmet Sarp Yalim,Yang Liu,Nikolai Pogorelov

doi:10.1088/1742-6596/837/1/012015

Abstract

We have developed a data-driven magnetohydrodynamic (MHD) model of the global solar corona which uses characteristically-consistent boundary conditions (BCs) at the inner boundary. Our global solar corona model can be driven by different observational data including Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI) synoptic vector magnetograms together with the horizontal velocity data in the photosphere obtained by the time-distance helioseismology method, and the line-of-sight (LOS) magnetogram data obtained by HMI, Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI), National Solar Observatory/Global Oscillation Network Group (NSO/GONG) and Wilcox Solar Observatory (WSO). We implemented our model in the Multi-Scale Fluid-Kinetic Simulation Suite (MS-FLUKSS) – a suite of adaptive mesh refinement (AMR) codes built upon the Chombo AMR framework developed at the Lawrence Berkeley National Laboratory. We present an overview of our model, characteristic BCs, and two results we obtained using our model: A benchmark test of relaxation of a dipole field using characteristic BCs, and relaxation of an initial PFSS field driven by HMI LOS magnetogram data, and horizontal velocity data obtained by the time-distance helioseismology method using a set of non-characteristic BCs.

Highlights

The solar wind (SW) emerging from the Sun is the main driving mechanism of solar events which may lead to geomagnetic storms which are the primary causes of space weather disturbances that affect the magnetic environment of Earth and may have hazardous effects on the space-borne and ground-based technological systems as well as human health
Relaxation of a dipole magnetic field to a quasi-steady state We present the results of a benchmark test that we performed to validate our characteristic boundary conditions (BCs) formulations
We relax this configuration to a quasi-steady state using our characteristic BCs. We performed another simulation with exactly the same grid, numerical schemes and initial conditions, but this time, using a set of non-characteristic BCs (i.e., n = 1.5 × 108 cm−3, Br = (Br)Dipole, Bθ = (Bθ)Dipole, vθ = vφ = 0, while Bφ, vr, and p have zero derivative in the radial direction) instead. Notice that both sets of BCs have the same physical BCs corresponding to the subslow inflow case in Table 1, whereas the rest of the variables are either obtained from the compatibility equations or their radial derivatives are assumed to be zero

Summary

Introduction

The solar wind (SW) emerging from the Sun is the main driving mechanism of solar events which may lead to geomagnetic storms which are the primary causes of space weather disturbances that affect the magnetic environment of Earth and may have hazardous effects on the space-borne and ground-based technological systems as well as human health. Our model is driven by Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI ) synoptic vector magnetograms together with the horizontal velocity data in the photosphere obtained, e.g., with the time-distance helioseismology method [9].

Results

Conclusion