EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Modification of the magnetosheath due to the high-speed jets propagation.

Oleksandr Goncharov1, Herbert Gunell1, Maria Hamrin1, Linus Norenius1, and Olga Gutynska2
Oleksandr Goncharov et al.
  • 1Umea University, Faculty of Science and Technology, Department of Physics, Umea, Sweden
  • 2Charles University, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, Prague, Czech Republic

Plasmoids, defined as plasma entities with a higher anti-sunward velocity component than the surrounding plasma, have been observed in the magnetosheath in recent years. Among other denominations, plasmoids are also called “magnetosheath jets” and can be classified by transient localized enhancements in dynamic pressure. Propagating through the magnetosheath, jets do not only affect the magnetopause and magnetosphere. Jets pushed slower ambient magnetosheath plasma out of their way. As a result, plasma moves around the jets, and it is slowed down or could even be pushed in the sunward direction. Consequently, jets may create anomalous flows and be a source of additional turbulence. Using the magnetosheath measurements by the Magnetospheric Multiscale (MMS) and THEMIS spacecraft, and comparing several criteria, we have identified several thousand events in the wide range of bow shock distances. Previous statistical studies have shown that jet occurrence is almost exclusively controlled by the angle between the IMF and the Earth–Sun line (cone angle), and jets are predominantly observed when this cone angle is small. However, high-speed jets downstream of the quasi-perpendicular bow shock are very common. Our statistical analysis shows differences of jets evolution in the quasi-parallel and quasi-perpendicular magnetosheath regions. We discuss their properties, nature and relation to anomalies regions in the magnetosheath.

How to cite: Goncharov, O., Gunell, H., Hamrin, M., Norenius, L., and Gutynska, O.: Modification of the magnetosheath due to the high-speed jets propagation., EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-3335,, 2020