Causes of jets in the quasi-perpendicular magnetosheath

TL;DR

This study investigates the origins of magnetosheath jets in the quasi-perpendicular region, identifying multiple mechanisms beyond shock rippling, which could influence magnetopause interactions and magnetospheric dynamics.

Contribution

It reveals that magnetosheath jets in quasi-perpendicular regions can originate from various processes, not just shock rippling, expanding understanding of their formation mechanisms.

Findings

Jets associated with flux tubes connected to quasi-parallel bow-shock

Jets linked to non-reconnecting current sheets

Jets related to reconnection exhausts and mirror mode waves

Abstract

Magnetosheath jets are currently an important topic in the field of magnetosheath physics. It is thought that 97~\% of the jets are produced by the shock rippling at quasi-parallel shocks. Recently, large statistical studies of magnetosheath jets have been performed, however it is not clear whether rippling also produces jets found downstream of quasi-perpendicular shocks. We analyze four types of events in the quasi-perpendicular magnetosheath with signatures characteristic of magnetosheath jets, namely increased density and/or dynamic pressure, that were not produced by the shock rippling: 1) magnetic flux tubes connected to the quasi-parallel bow-shock, 2) non-reconnecting current sheets, 3) reconnection exhausts and 4) mirror mode waves. The flux tubes are downstream equivalents of the upstream traveling foreshocks. Magnetosheath jets can impact the magnetopause, so knowing the conditions under which they form may enable us to understand their signatures in the magnetosphere.