Carriers of the Field‐Aligned Currents in the Plasma Sheet Boundary Layer: An MMS Multicase Study. Issue 4 (30th April 2019)

• Record Type: Journal Article
• Authors: Chen, YuanQiang; Wu, Mingyu; Wang, Guoqiang; Schmid, Daniel; Zhang, Tielong; Nakamura, Rumi; Baumjohann, Wolfgang; Burch, James L.; Giles, Barbara J.; Russell, Christopher T.
• Is Part Of: Journal of geophysical research. Volume 124:Issue 4(2019)
• Page Start: 2873
• Page End: 2886
• Publication Date: 2019-04-30
• Subjects: field‐aligned current -- PSBL -- current carrier -- magnetosphere; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2018JA026216
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: With the advantage of fast plasma measurements of the Magnetospheric Multiscale (MMS) mission in the magnetotail, we first investigate the particle carriers of field‐aligned currents (FACs) in the plasma sheet boundary layer for three cases. In all cases, electrons are the main carriers of FACs, while the contribution of ions can be neglected. The analysis of these cases indicate that thermal electrons (energy range from 0.5 T e to 5 T e, where T e is the electron parallel temperature) are the main carrier of the FACs. However, cold electrons (energy less than 0.5 T e ) can also significantly contribute to the FACs. In one of three cases, suprathermal electrons (energy greater than 5 T e ) contribute but a small portion to the total current. The difference between the cases may depend on the local dynamics in the magnetotail. Then a statistical analysis was performed, which also shows that the thermal electrons are dominant in most of the FACs, while the cold electrons can be dominant in some cases. However, the suprathermal electrons cannot support the FACs solely, and they and the cold electrons are more often supporting the FACs together with the thermal electrons. Key Points: The FACs observed in the PSBL are mainly carried by electrons, while ionic contributions are less important Further investigation using particle energy flux demonstrates that the main contribution to the FACs comes from thermal electrons Weak suprathermal and cold electron contributions to the FACs are observed in some cases