Investigating the Dynamics and Variability of ICME Sheaths and Magnetic Obstacles Across Solar Cycles

We conducted a comprehensive statistical analysis of the evolution of coronal mass ejections (CMEs) and their embedded magnetic obstacles with and without driving a sheath. Specifically, we explored the thermal and magnetic pressure within the different CME regions, alongside with the open solar flux (OSF) through various solar cycles. Preliminary results indicate significant differences in the fluctuations of the mean and standard deviation of the magnetic field between solar cycles 23 and 24. The analysis reveals that the sheath total pressure is higher than that of magnetic obstacles, with a notable decrease in pressure from solar cycle 23 to 24. Likewise, the OSF shows a decrease from solar cycle 23 to 24, correlating with the observed CME pressure trends. These findings suggest that the characteristics of ICME sheath regions and magnetic obstacles vary depending on the ambient solar wind conditions present during each individual cycle. This research represents an initial step towards a more comprehensive understanding of the dynamics and variability of ICME sheaths, with implications for space weather forecasting and modeling.