Solar-Terrestrial Simulations of CMEs with a Realistic Initiation Mechanism: Case Study for Active Region 10069

TL;DR

This paper presents realistic 3D MHD simulations of CMEs originating from active region 10069, demonstrating how magnetic reconnection influences CME deflection, connectivity, and solar energetic particle fluxes, with validation against in situ ACE data.

Contribution

It introduces a simulation approach that models CME initiation from active region magnetic field evolution, improving understanding of CME propagation and magnetic connectivity.

Findings

CME deflection is influenced by magnetic reconnection with neighboring structures.

Simulations match observed CME speeds and trajectories.

Altered magnetic connectivity affects solar energetic particle predictions.

Abstract

Most simulations of coronal mass ejections (CMEs) to date either focus on the interplanetary propagation of a giant plasma "blob" without paying too much attention to its origin and to the formation process or they focus on the complex evolution of the coronal magnetic field due to (sub-)photospheric motions which result in an eruption. Here, we present global simulations of CMEs where coronal motions are used to produce a realistic evolution of the coronal magnetic field and cause an eruption. We focus on active region 10069, which produced a number of eruptions in late August 2002, including the August 24, 2002 CME - a fast (~2000 km/s) eruption originating from W81-, as well as a slower eruption on August 22, 2002 (originating from W62). Using a three-dimensional magneto-hydrodynamic (MHD) simulation of these ejections with the Space Weather Modeling Framework (SWMF), we show how a realistic initiation mechanism enables us to study the deflection of the CME in the corona and in the heliosphere. Reconnection of the erupting magnetic field with that of neighboring streamers and active regions modify the solar connectivity of the field lines connecting to Earth and change the expected solar energetic particle fluxes. Comparing the results at 1 AU of our simulations with in situ observations by the ACE spacecraft, we propose an alternate solar origin for the shock wave observed at L1 on August 26.