Downstream high-speed plasma jet generation as a direct consequence of shock reformation

Savvas Raptis; Tomas Karlsson; Andris Vaivads; Craig Pollock; Ferdinand Plaschke; Andreas Johlander; Henriette Trollvik; Per-Arne Lindqvist

doi:10.1038/s41467-022-28110-4

Downstream high-speed plasma jet generation as a direct consequence of shock reformation

Nat Commun. 2022 Feb 1;13(1):598. doi: 10.1038/s41467-022-28110-4.

Authors

Savvas Raptis¹, Tomas Karlsson², Andris Vaivads², Craig Pollock³, Ferdinand Plaschke^{4

5}, Andreas Johlander^{6

7}, Henriette Trollvik², Per-Arne Lindqvist²

Affiliations

¹ Division of Space and Plasma Physics - KTH Royal Institute of Technology, Stockholm, Sweden. savvra@kth.se.
² Division of Space and Plasma Physics - KTH Royal Institute of Technology, Stockholm, Sweden.
³ Denali Scientific, Fairbanks, AK, 99709, USA.
⁴ Institute of Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig, Brunswick, Germany.
⁵ Space Research Institute, Austrian Academy of Sciences, Graz, Austria.
⁶ Department of Physics, University of Helsinki, Helsinki, Finland.
⁷ Swedish Institute of Space Physics, Uppsala, Sweden.

Abstract

Shocks are one of nature's most powerful particle accelerators and have been connected to relativistic electron acceleration and cosmic rays. Upstream shock observations include wave generation, wave-particle interactions and magnetic compressive structures, while at the shock and downstream, particle acceleration, magnetic reconnection and plasma jets can be observed. Here, using Magnetospheric Multiscale (MMS) we show in-situ evidence of high-speed downstream flows (jets) generated at the Earth's bow shock as a direct consequence of shock reformation. Jets are observed downstream due to a combined effect of upstream plasma wave evolution and an ongoing reformation cycle of the bow shock. This generation process can also be applicable to planetary and astrophysical plasmas where collisionless shocks are commonly found.