EGU23-10625, updated on 26 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Modification of magnetosheath jet occurrence and properties within CMEs and SIRs

Florian Koller1, Ferdinand Plaschke2, Luis Preisser3, Manuela Temmer1, Owen Roberts3, and Zoltan Vörös3,4
Florian Koller et al.
  • 1University of Graz, Institute of Physics, IGAM, Graz, Austria
  • 2Institut für Geophysik und extraterrestrische Physik, TU Braunschweig, Germany
  • 3Space Research Institute, Austrian Academy of Sciences, Graz, Austria
  • 4Institute of Earth Physics and Space Science, ELRN, Sopron, Hungary

Large-scale solar wind (SW) structures like coronal mass ejections (CMEs) and stream interaction regions (SIRs) significantly alter the plasma within the Earth’s magnetosheath and change the foreshock region. Thus, they modulate the number and the parameters of dynamic pressure transients in the magnetosheath, which we call magnetosheath jets. We use THEMIS spacecraft data from 2008 to 2022 to detect these jets in the magnetosheath and OMNI data for the SW within the same time range. We investigate which properties in each SW structure primarily influence the jet occurrence. We find that CMEs cause a reduction in jet occurrence due to the mix of high magnetic field strength, high plasma beta, low Mach number, and high cone angles. These conditions most likely disrupt the building of a proper foreshock region and thus hinder the major generation mechanism for jets in the magnetosheath. On the other hand, high speed streams in SIRs show favorable conditions for jet generation in all plasma parameters, most importantly due to the high probability for low cone angles, the low density, high velocity, and low magnetic field strength. We analyze how the jet parameters differ in each type of  SW structure and discuss how this influences the geoeffectiveness of jets.

How to cite: Koller, F., Plaschke, F., Preisser, L., Temmer, M., Roberts, O., and Vörös, Z.: Modification of magnetosheath jet occurrence and properties within CMEs and SIRs, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10625,, 2023.