Evolution of sheaths and magnetic obstacle from the inner to the outer heliosphere.
- 1Universidad de Alcalá, Science faculty, Physics and Mathematics, Alcalá de Henares, Spain (carlos.larrodera@uah.es)
- 2Institute of Physics, University of Graz, Graz, Austria (manuela.temmer@uni-graz.at)
Our study covers a comprehensive analysis of Interplanetary Coronal Mass Ejections (ICMEs) across a wide distance from 0.25-5.42 AU and temporal range from 1975-2022. Our primary focus is a statistical examination of a variety of physical parameters for the structures within ICMEs, specifically the sheath and magnetic obstacle (MO). Our methodological approach integrates data merging from 13 individual ICME catalogs into a unified catalog, facilitating a comprehensive evaluation of in-situ measurements obtained from diverse spacecraft. This approach offers an opportunity to discern variances across different solar cycles. Our empirical findings provide intriguing insights. Notably, MOs preceded by a sheath exhibit a marked increase in size upon reaching 1 AU from the Sun. Furthermore, both structures, MO and sheath, experience a strong increase in size around 0.75 AU, correlating with a decrease in the measured density at this distance. Moreover, our analysis reveals a shift in the spatial positioning of material accumulation proximate to the sheath interface. This transformation suggests a potential transition in the underlying mechanism governing sheath formation, indicating a shift from externally driven to internally accumulated material processes.
How to cite: Larrodera, C. and Temmer, M.: Evolution of sheaths and magnetic obstacle from the inner to the outer heliosphere. , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10017, https://doi.org/10.5194/egusphere-egu24-10017, 2024.