How coronal mass ejections are influenced by the morphology and toroidal flux of their source magnetic flux ropes?

TL;DR

This study investigates how the morphology and toroidal flux of solar magnetic flux ropes influence the properties and propagation of coronal mass ejections, enhancing space weather prediction capabilities.

Contribution

It introduces a novel dataset of flux ropes with varied shapes and fluxes, and uses MHD simulations to link source magnetic structures to CME characteristics.

Findings

Projection shape affects CME magnetic structure at 20 R_sun.

Toroidal flux correlates with CME speed and eruption success.

Source flux rope parameters are key for predicting CME behavior.

Abstract

Coronal mass ejections (CMEs) stand as intense eruptions of magnetized plasma from the Sun, playing a pivotal role in driving significant changes of the heliospheric environment. Deducing the properties of CMEs from their progenitors in solar source regions is crucial for space weather forecasting. Deducing the properties of CMEs from their progenitors in solar source regions is crucial for space weather forecasting. The primary objective of this paper is to establish a connection between CMEs and their progenitors in solar source regions, enabling us to infer the magnetic structures of CMEs before their full development. To this end, we create a dataset comprising a magnetic flux rope series with varying projection shapes, sizes and toroidal fluxes, using the Regularized Biot-Savart Laws (RBSL). Thereafter, we simulate the propagation of these flux ropes from the solar surface to a distance of 25$R_{\odot}$ with our global coronal MHD model which is named COCONUT. Our parametric survey reveals significant impacts of source flux ropes on the consequent CMEs. We find that the projection shape can influence the magnetic structures of CMEs at 20$R_{\odot}$, albeit with minimal impacts on the propagation speed. However, these impacts diminish as source flux ropes become fat. In terms of toroidal flux, our simulation results demonstrate a pronounced correlation with the propagation speed of CMEs, as well as the successfulness in erupting. This work builds the bridge between the CMEs in the outer corona and their progenitors in solar source regions. Our parametric survey suggests that the projection shape, cross-section radius and toroidal flux of source flux ropes are crucial parameters in predicting magnetic structures and propagation speed of CMEs, providing valuable insights for space weather prediction.