Magnetic cloud prediction model for forecasting space weather relevant properties of Earth-directed coronal mass ejections

Abstract

Context. Coronal mass ejections (CMEs) are major eruptive events on the Sun that result in the ejection of large-scale magnetic clouds (MCs) in interplanetary space, consisting of plasma with enhanced magnetic fields whose direction changes coherently when measured in situ. The severity of CME-induced geomagnetic perturbations and space weather impacts depends on the direction and strength of the interplanetary magnetic field (IMF), as well as on the speed and duration of the passage of the magnetic cloud associated with the storm. The coupling between the heliospheric environment and Earth's magnetosphere is strongest when the IMF direction is persistently southward (i.e. negative B z ) for a prolonged period. Predicting the magnetic profile of such Earth-directed CMEs is therefore critical for estimating their space weather consequences; this remains an outstanding challenge, however. Aims. Our aim is to build upon and integrate diverse techniques towards the development of a comprehensive magnetic cloud prediction (MCP) model that can forecast the magnetic field vectors, Earth-impact time, speed, and duration of passage of solar storms. Methods. The configuration of a CME is approximated as a radially expanding force-free cylindrical structure. Combining near-Sun geometrical, magnetic, and kinematic properties of CMEs with the probabilistic drag-based model and cylindrical force-free model, we propose a method for predicting the Earth-arrival time, propagation speed, and magnetic vectors of MCs during their passage through 1 AU. Our model is able to predict the passage duration of the storm without recourse to computationally intensive timedependent dynamical equations. Results. Our method is validated by comparing the MCP model output with observations of ten MCs at 1 AU. In our sample, we find that eight MCs show a root mean square (rms) deviation smaller than 0.1 between the predicted and observed magnetic profiles, and the passage durations of seven MCs fall within the predicted range. Conclusions. Based on the success of this approach, we conclude that predicting the near-Earth properties of MCs based on an analysis and modelling of near-Sun CME observations is a viable endeavour with potential applications for the development of early-warning systems for space weather and enabling mitigation strategies.

Global insight into a complex-structured heliosphere based on the local multi-point analysis

“…If a CME originates close to CHs, its expansion and propagation are prohibited in the direction of CH open fields and its propagation path is deflected by the magnetic gradient resulting from the difference in the magnetic field strength of the surrounding flux system (Manchester et al, 2017;Heinemann et al, 2019). These effects alter the initial ICME properties close to the Sun and can lead to significant errors in predictions of ICME arrival time and geoeffectiveness (Pal et al, 2022b).…”

“…This calls for improvement in tools such as data assimilation, statistical analysis, and synthesis of observations and models (Daglis et al, 2021). Several studies have analyzed interacting large-scale solar wind phenomena using multipoint observations supported by heliospheric modeling and their space weather impacts (Farrugia et al, 2011;Winslow et al, 2021;Pal et al, 2022b). However, the existence of a series of solar wind transients (similar or different kinds) and their interactions are not very usual.…”

Using Solar Orbiter as an Upstream Solar Wind Monitor for Real Time Space Weather Predictions

“…Such parameters influence the dynamic pressure of the CME and its ability to trigger magnetic reconnection at the magnetopause (Vasyliunas et al., 1982), which leads to the onset of geomagnetic storms. The orientation of the magnetic field in the CME, whether B z is positive or negative, is the primary indicator of storm severity (Gonzalez et al., 1999; Tsurutani et al., 1988; Vasyliunas et al., 1982), although predicting this property remains a challenging problem for CME models (Kay et al., 2017; Möstl et al., 2018; Pal et al., 2022; Reiss et al., 2021; Sarkar et al., 2020; Savani et al., 2015). Therefore, it would be a major advantage if the transient structures seen by a spacecraft within 1 au were correlated with those subsequently seen at Earth.…”

Collection, Collation, and Comparison of 3D Coronal CME Reconstructions

“…Forecasting the southward magnetic field is one of the most important factors in determining the severity of a near‐Earth CME impact. In fact, many works have focused on connecting CME axial orientations estimated at the Sun and subsequently at 1 au (e.g., Martinić et al., 2023; Pal et al., 2022; Palmerio et al., 2017), finding often striking discrepancies between the two tilts (e.g., Palmerio et al., 2018; Xie et al., 2021; Yurchyshyn et al., 2007). Even more so, it has been proposed that (at least some) CMEs propagate through interplanetary space as significantly kinked structures, and the axis orientation encountered at Earth (or any other point in the heliosphere) only reflects the local conditions of the portion of the cloud that is sampled by a spacecraft (Bothmer & Mrotzek, 2017).…”