IIA researchers have developed a 3-D model to predict the arrival of a coronal mass ejection

Researchers from the Indian Institute of Astrophysics (IIA), along with their overseas collaborators, have developed a three-dimensional (3D) computer simulation model that can help more accurately predict the arrival and impact of coronal mass ejections (CMEs) before they reach Earth.

CMEs are massive explosions of magnetized plasma shot out from the Sun at millions of kilometers per hour, and when directed toward Earth, they can damage satellite systems, disrupt power grids, and interfere with global communications.

According to the Department of Science and Technology, at the heart of these explosions are magnetic flux ropes (MFRs), which are twisted bundles of magnetic field lines embedded in the plasma, and are widely considered the primary triggers of CMEs.

“However, how magnetic energy accumulates and then is released during a coronal ejection has remained one of the most stubborn mysteries of solar physics through violent ejection, and has not been well understood until now,” the ministry said.

This 3D model tracks, step-by-step, how the reconnection flux changes as the magnetic flux rope rises, the surrounding magnetic field expands, and eventually explodes.

The model starts with a realistic coronal setting of the solar atmosphere, which is coupled to a magnetic field configuration that resembles a coronal streamer in the observation.

“A twisted magnetic flux rope is gradually inserted from below, simulating how new magnetic flux emerges from beneath the surface of the Sun,” the administration added. She also added that as the flux rope rises, the team observed in their computer models that the overlying magnetic field expands and compresses dramatically beneath it.

“Reconnection does not begin explosively. Instead, it begins quietly with the slow formation of a thin layer of strong electrical current, a thin layer where opposing magnetic fields are pushed together. Over time, this process intensifies, culminating in the large-scale impulsive expulsion of the flux rope,” he added.

The researchers simulated two successive flux rope explosions in their model, and validated their findings with another researcher from the University of Helsinki, Finland, who collaborated with the Indian group to contribute to the analysis based on observational data from NASA’s Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Array (AIA), two of the most powerful instruments currently observing the Sun.

Samriddhi Sankar Maiti (postdoctoral researcher at NASA and Georgia State University, USA), Piyali Chatterjee, IIA and Ejas S. Mithin (PhD student, Eötvös University, Hungary) and Randeep Sarkar (PhD student, Eötvös University, Hungary).