Connection of the magnetosheath jet-like structures with the foreshock and impact on the magnetopause

Abstract

Plasma structures with enhanced dynamic pressure, density or speed are often observed in Earth’s magnetosheath. These structures, known as jets and fast plasmoids, can be registered in the magnetosheath, downstream of both the quasi-perpendicular and quasi-parallel bow shocks Using measurements by the Magnetospheric Multiscale (MMS) spacecraft, Goncharov et al., (2020) showed similarities in the plasma properties of the jets and fast plasmoids. On the other hand, they pointed out that the different magnetic fields inside the structures suggest that the formation mechanisms are not the same. Hybrid simulations by Preisser et al., (2020) have shown differences in the mechanisms of jet and embedded plasmoid formation. Previous studies established that foreshock structures can be a source of the jets (Raptis et al., 2022). Xirogiannopoulou et al. (2023) found that the subsolar foreshock contains several types of structures with enhanced density or/and magnetic field magnitude, like plasmoids, SLAMS and mixed structures. Following the results of Xirogiannopoulou et al. (2023) and Goncharov et al., (2020), we compare our MMS measurements with THEMIS observations. Based on our comparative analysis, we discuss features of jet-like structures, their properties, occurrence, evolution, relation to the foreshock, and impact on the magnetopause.