Abstract Details


Name: Wageesh Mishra
Affiliation: Indian Institute of Astrophysics, Bengaluru
Conference ID: TVS202510307
Title: Thermal State of CMEs and Its Space Weather Implications
Authors and Co-Authors:
Abstract Type: Invited by SOC
Abstract: Coronal Mass Ejections (CMEs) are powerful solar eruptions that expel magnetized plasma into the heliosphere, often driving severe space weather at Earth. While their large-scale kinematics and magnetic structures are relatively well understood, their internal thermodynamic evolution remains less explored. In this study, we investigate the thermal state of CMEs using in-situ observations at 1 AU, with a particular focus on the polytropic index as a diagnostic. A statistical analysis of magnetic ejecta (MEs) across Solar Cycles 23–25 shows that nearly half of the events experience net heating during propagation, especially near solar maxima. Cycle-dependent trends indicate a shift toward more cooling-dominated states in Cycle 24. Magnetic clouds (MCs) consistently emerge as the most geoeffective structures, characterized by strong magnetic fields, low plasma beta, and suppressed polytropic index values. Superposed epoch analyses further reveal systematic thermodynamic and magnetic variations across distinct ICME substructures. Together, these results provide a unified thermodynamic perspective of CMEs, emphasizing their variable heating behavior and its implications for CME modeling and space weather prediction.