On the structure of magnetosheath jets

Plasma structures with the enhanced dynamic pressure, density, or speed are often observed in the Earth’s magnetosheath. These structures, known as magnetosheath (MSH) jets, can be detected downstream quasi-perpendicular and quasi-parallel bow shocks. The structures are highly turbulent and dynamic, and their properties can change significantly, depending on their location and actual orientation of the interplanetary magnetic field (IMF). Recent hybrid-kinetic simulations by Fatemi et al. (2024) have shown that magnetosheath jets, previously emphasized to be simple geometric forms, are complex and interconnected structures that frequently merging or splitting as they move through the magnetosheath. Furthermore, hybrid simulation results have shown that the plasma surrounding these jets can exhibit flow directions perpendicular to or even sunward relative to the solar wind. This highlights the potential for in situ measurements to resolve these small-scale structures and their peculiarities, thereby providing insights into the applicability of such hybrid-kinetic simulations. In the work, we aim to study such a complex magnetosheath jet structure using multi-point spacecraft measurements (THEMIS/MMS) and to compare them with outputs of hybrid simulations.