SWASTi: A physics-based modelling toolkit for space weather

Abstract

Space weather poses significant risks to technical systems and the global economy, making it a critical area of research. Coronal mass ejections (CMEs) are the primary drivers of space weather and can cause intense geomagnetic disturbances. The solar wind (SW) governs CME propagation in the heliosphere and drives geomagnetic storm activities. Understanding the evolution of SW stream interaction regions (SIRs), CMEs, and their interactions in the inner heliosphere is essential for accurately predicting their arrival times and mitigating their impacts. This study presents a review of Space Weather Adaptive Simulation (SWASTi), an indigenous three-dimensional magnetohydrodynamic (MHD) modelling framework, with a focus on its SW and CME modules. Comparative analysis with in situ observations demonstrates the model’s robustness, revealing the significant role of ambient SW conditions in shaping the morphological and dynamical properties of CMEs. The geo-effective impact of CME-CME interactions are also explored with a particular focus on the recent Gannon storm. Furthermore, the study discusses how in situ measurements from the Aditya-L1 mission can synergise with the SWASTi framework. This integrated approach, leveraging Aditya-L1 data and SWASTi’s 3D MHD simulations, provides new insights into the complex behaviour of solar wind, SIRs, and CMEs, promising significant advancements in near-real-time space weather forecasting. © 2025 Elsevier B.V., All rights reserved.