2010 August 1-2 sympathetic eruptions: II. Magnetic topology of the MHD background field

Abstract

Using a potential field source surface (PFSS) model, we recently analyzed the global topology of the background coronal magnetic field for a sequence of coronal mass ejections (CMEs) that occurred on 2010 August 1-2. Here we repeat this analysis for the background field reproduced by a magnetohydrodynamic (MHD) model that incorporates plasma thermodynamics. As for the PFSS model, we find that all three CME source regions contain a coronal hole that is separated from neighboring coronal holes by topologically very similar pseudo-streamer structures. However, the two models yield very different results for the size, shape, and flux of the coronal holes. We find that the helmet-streamer cusp line, which corresponds to a source-surface null line in the PFSS model, is structurally unstable and does not form in the MHD model. Our analysis indicates that generally, in MHD configurations, this line rather consists of a multiple-null separator passing along the edge of disconnected flux regions. Some of these regions are transient and may be the origin of so-called streamer blobs. We show that the core topological structure of such blobs is a three-dimensional "plasmoid", consisting of two conjoined flux ropes of opposite handedness, which connect at a spiral null point of the magnetic field. Our analysis reveals that such plasmoids appear also in pseudo-streamers on much smaller scales. These new insights into the coronal magnetic topology provide some intriguing implications for solar energetic particle events and for the properties of the slow solar wind.

arXiv comment29 pages, 7 figures

References in corpus (17)

• The Two Sources of Solar Energetic Particles
• A Model for the Sources of the Slow Solar Wind
• Structure, Stability, and Evolution of Magnetic Flux Ropes from the Perspective of Magnetic Twist
• Generalized Squashing Factors for Covariant Description of Magnetic Connectivity in the Solar Corona
• A model for magnetically coupled sympathetic eruptions
• Magnetic Topology of Coronal Hole Linkages
• A Model for the Escape of Solar-Flare Accelerated Particles
• 2010 August 1-2 sympathetic eruptions: I. Magnetic topology of the source-surface background field
• Non-linear Tearing of 3D Null Point Current Sheets
• May 12 1997 Cme Event: I. a Simplified Model of the Pre-Eruptive Magnetic Structure
• A Numerical Study of Long-Range Magnetic Impacts during Coronal Mass Ejections
• Pathways of large-scale magnetic couplings between solar coronal events
• Slip-Squashing Factors as a Measure of Three-Dimensional Magnetic Reconnection
• Dynamic Topology and Flux Rope Evolution During Non-linear Tearing of 3D Null Point Current Sheets
• QSL Squasher: A Fast Quasi-Separatrix Layer Map Calculator
• Disconnecting Solar Magnetic Flux
• Insight Into "Changing-Look" AGN Mrk 1018 from the Fe K$\alpha$ Line: The Reprocessing Gas Has Yet to Fully Respond to the Fading of the AGN

Cited by in corpus (8)

• Sun-to-Earth MHD Simulation of the 14 July 2000 "Bastille Day" Eruption
• Decoding the Pre-Eruptive Magnetic Field Configurations of Coronal Mass Ejections
• A Model for the Coupled Eruption of a Pseudostreamer and Helmet Streamer
• Energetic Proton Propagation and Acceleration Simulated for the Bastille Day Event of July 14, 2000
• Coupled MHD-Focused Transport Simulations for Modeling Solar Particle Events
• Optimization of Magnetic Flux Ropes Modeled with the RBSL method
• Flaring together: A preferred angular separation between sympathetic flares on the Sun
• Slip-Back Mapping as a Tracker of Topological Changes in Evolving Magnetic Configurations