EGU24-10017, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-10017
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evolution of sheaths and magnetic obstacle from the inner to the outer heliosphere. 

Carlos Larrodera1 and Manuela Temmer2
Carlos Larrodera and Manuela Temmer
  • 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.