Assessing the Influence of Input Magnetic Maps on Global Modeling of the Solar Wind and CME-Driven Shock in the 2013 April 11 Event

In the past decade, significant efforts have been made in developing physics-based solar wind and coronal mass ejection (CME) models, which have been or are being transferred to national centers (e.g., SWPC, Community Coordinated Modeling Center) to enable space weather predictive capability. However, the input data coverage for space weather forecasting is extremely limited. One major limitation is the solar magnetic field measurements, which are used to specify the inner boundary conditions of the global magnetohydrodynamic (MHD) models. In this study, using the Alfven wave solar model, we quantitatively assess the influence of the magnetic field map input (synoptic/diachronic vs. synchronic magnetic maps) on the global modeling of the solar wind and the CME-driven shock in the 11 April 2013 solar energetic particle event. Our study shows that due to the inhomogeneous background solar wind and dynamical evolution of the CME, the CME-driven shock parameters change significantly both spatially and temporally as the CME propagates through the heliosphere. The input magnetic map has a great impact on the shock connectivity and shock properties in the global MHD simulation. Therefore this study illustrates the importance of taking into account the model uncertainty due to the imperfect magnetic field measurements when using the model to provide space weather predictions. Plain Language Summary As the origin of space weather, solar wind and coronal mass ejection (CMEs) play an important part in the space weather prediction. Similar as the terrestrial weather forecast, advanced models are developed driven by the available observations. However, the input data coverage for space weather forecasting is extremely limited. One major input data used to drive the solar wind and CME models is the solar surface magnetic field, for which the current telescopes can only observe less than half of the surface therefore assumptions are needed for the rest that leads to different types of magnetic maps. In this study, we quantitatively assess the influence of the two widely used magnetic maps on the global modeling of the solar wind the CME-driven shock in the 11 April 2013 event. Our result suggests that the input magnetic map has a great impact on the simulated background solar wind, CME-driven shock properties, as well as the spacecraft connectivity. Our study illustrates the importance of considering the model uncertainty due to the limited magnetic field coverage when using the model for research or space weather forecasting purposes.

Automated summary

This study quantitatively assesses the influence of magnetic field map input on the global modeling of solar wind and CME-driven shock. The results show that the input magnetic map significantly affects the simulated background solar wind, CME-driven shock properties, and spacecraft connectivity. The study highlights the importance of considering the model uncertainty due to limited magnetic field coverage when using the model for research or space weather forecasting.