Speaker
Description
Our Sun is a dynamic star that produces energetic events known as coronal mass ejections (CMEs). These ejections are driven by the Sun's magnetic fields, which facilitate their movement through the heliosphere. The propagation of CMEs is primarily affected by the ambient solar wind medium, which ultimately influences their arrival time. In general, the magnetic field configurations on the Sun and the background solar wind play a significant role in how CMEs travel through interplanetary space, determining their travel time and their magnetic field properties when they impact the Earth. Thus, CMEs play a crucial role in shaping space weather, influencing both the heliosphere and geospace. As the solar activity varies with time, the effects of CMEs in the near-Earth environment can also significantly vary and differ from one event to another.
I will discuss the effects of coronal mass ejections (CMEs) on Earth, focusing on the geoeffective event of Solar Cycle 25 in April 2023, which resulted in an intense geomagnetic storm. We employ advanced observational and modeling methods and integrating multi-wavelength and multi-point remote sensing observations of this event, to study the propagation of the CME from the Sun to Earth. Further, we utilize the interplanetary flux rope simulator (INFROS) model to forecast the magnetic vectors of the interplanetary CME (ICME) at 1 AU. Additionally, we combined INFROS with the Drag-Based Model (DBM) and empirical Dst prediction models to create a space weather modeling framework aimed at estimating the severity of the related geomagnetic storm. The April 2023 event offered a distinctive chance to assess the space weather implications i.e. ionospheric and geomagnetic effects. The study demonstrates significant longitudinal asymmetries in ionospheric response and highlights the varying geomagnetic signatures associated with ICME substructures. The combined analysis underscores the importance of electric fields, neutral winds, and solar wind drivers in governing magnetosphere–ionosphere coupling during intense space weather events. I will also discuss the limitations and challenges linked to modeling such occurrences for improving space weather forecasting.