IIA researchers develop 3D model to forecast arrival of Coronal Mass Ejections

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

The CMEs are gigantic eruptions of magnetised plasma hurled from the sun at millions of kmph 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 eruptions lie magnetic flux ropes (MFRs), which are twisted bundles of magnetic field lines embedded in the plasma, and are widely regarded as the primary triggers of the CME.

“Yet, how the magnetic energy builds up, and is then released during the CMEs has remained one of solar physics’ most stubborn mysteries through the violent expulsion has been poorly understood until now,” the department said.

This 3D model traces, step by step, how the reconnection flux changes as a magnetic flux rope rises, stretches the surrounding ambient magnetic field, and ultimately erupts.

The model begins with a realistic coronal setup of a solar atmosphere, which is threaded by a magnetic field configuration resembling a coronal streamer in observation.

“A twisted magnetic flux rope is gradually introduced into this from below, mimicking how new magnetic flux emerges from beneath the solar surface,” the department added. It further added that as the flux rope rises, the team observed in their computer models that the overlying magnetic field is significantly stretched and compressed beneath it.

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

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

Samriddhi Sankar Maity (postdoc at NASA & Georgia State University, U.S.), Piyali Chatterjee, IIA and Ijas S. Mytheen (PhD student, Eotvos University, Hungary) and Ranadeep Sarkar from the University of Helsinki, Finland, were part of the study which was published in Astrophysical Journal.