Numerical study of the propagation characteristics of coronal mass ejections in a structured ambient solar wind

Abstract

Using a three‐dimensional (3‐D) magnetohydrodynamics (MHD) model, we analyze and study the propagation characteristics of coronal mass ejections (CMEs) launched at different positions in a realistic structured ambient solar wind. Here the ambient solar wind structure during the Carrington rotation 2095 is selected, which is the characteristics of activity rising phase. CMEs with a simple spherical plasmoid structure are initiated at different solar latitudes with respect to the heliospheric current sheet (HCS) and the Earth in the same ambient solar wind. Then, we numerically obtained the evolution process of the CMEs from the Sun to the interplanetary space. When the Earth and the CME launch position are located on the same side of the HCS, the arrival time of the shock at the Earth is faster than that when the Earth and the CME launch position are located on the opposite side of the HCS. The disturbance amplitudes for the same side event are also larger than those for the opposite side event. This may be due to the fact that the HCS between the CME and the Earth for the opposite side event hinders its propagation and weaken it. The CMEs tend to deflect toward the HCS in the latitudinal direction near the corona and then propagate almost parallel to the HCS in the interplanetary space. This deflecting tendency may be caused by the dynamic action of near‐Sun magnetic pressure gradient force on the ejected coronal plasma.

Origins of the Ambient Solar Wind: Implications for Space Weather

“…CME flux ropes can be accelerated or decelerated by drag-like interactions with the surrounding solar wind (Gopalswamy et al 2000;Vršnak et al 2010;). Large-scale spatial structures in the wind can also distort CMEs, deflect their trajectories, and affect their overall strengths (Riley et al 1997;Odstrčil and Pizzo 1999;Wang et al 2004;Isavnin et al 2014;Zhou and Feng 2017). Thus, being able to predict the properties of the ambient solar wind appears to be a necessary component of predicting CME geoeffectiveness.…”

CESE‐HLL Magnetic Field‐Driven Modeling of the Background Solar Wind During Year 2008

“…Although the most severe space weather events result from a coronal mass ejection (CME) hitting Earth, the ambient solar wind is also a vital ingredient in space weather events (Schwenn, ). It has long been recognized that the propagation of CMEs are significantly influenced by the ambient solar wind lying in its path (Temmer et al, ; Zhou & Feng, ). Owens et al () suggest that besides being accelerated, decelerated, or deflected by the ambient solar wind, CMEs may also lose their coherent magnetohydrodynamics (MHD) structure when interacting with the structured solar wind background.…”

Unifying the Validation of Ambient Solar Wind Models

“…Third, the solar wind sets the conditions through which the most extreme forms of space weather, interplanetary coronal mass ejections, propagate (Gosling & Pizzo, 1999). Ample evidence shows that solar wind flows can distort and deflect interplanetary coronal mass ejections and thereby affect their severity (Riley et al, 1997;Odstrčil & Pizzo, 1999;Case et al, 2008;Zhou & Feng, 2017).…”