Formation of double layers during magnetic reconnection in the presence of flat-top distributions of particles: Theory and observations
Presentation Type
Talk
Presenter Format
Virtual Meeting Talk
Topic
Fundamental Processes in Comparative Magnetospheres
Start Date
13-5-2022 1:15 PM
Abstract
Several satellite missions have confirmed the existence of unipolar parallel electric fields in various regions of the terrestrial magnetosphere, including the plasma sheet region, the auroral region, and the magnetopause/magnetotail reconnection sites. Recently, Magnetospheric Multiscale (MMS) mission observed parallel electric field fluctuations up to 100 mV/m at the magnetic reconnection site of the Earth's magnetopause. These parallel electric fields are interpreted as double layers (DLs), which may cause secondary reconnection. Furthermore, DLs may occur within the reconnection exhaust, regulating the partitioning of the released magnetic energy during magnetic reconnection. In addition to DLs, particle distributions with superthermal tails and shoulders (flat-top distribution) have been reported in the literature based on MMS data. Motivated by the reported literature, we investigate DLs and their associated electric fields at the magnetopause magnetic reconnection site by using a simple analytical model in which the DLs associated with kinetic Alfvén waves are examined in a two-component flat-top distributed plasma. The flat-top distribution affects the DL's strength (as defined by the potential drop) and its associated parallel electric field. Our findings are consistent with previous research on DLs in the Earth's magnetosphere. Additionally, we discuss the implications of our findings on charged particle energization in the separatrix region of the Earth's magnetosphere using MMS data.
Formation of double layers during magnetic reconnection in the presence of flat-top distributions of particles: Theory and observations
Several satellite missions have confirmed the existence of unipolar parallel electric fields in various regions of the terrestrial magnetosphere, including the plasma sheet region, the auroral region, and the magnetopause/magnetotail reconnection sites. Recently, Magnetospheric Multiscale (MMS) mission observed parallel electric field fluctuations up to 100 mV/m at the magnetic reconnection site of the Earth's magnetopause. These parallel electric fields are interpreted as double layers (DLs), which may cause secondary reconnection. Furthermore, DLs may occur within the reconnection exhaust, regulating the partitioning of the released magnetic energy during magnetic reconnection. In addition to DLs, particle distributions with superthermal tails and shoulders (flat-top distribution) have been reported in the literature based on MMS data. Motivated by the reported literature, we investigate DLs and their associated electric fields at the magnetopause magnetic reconnection site by using a simple analytical model in which the DLs associated with kinetic Alfvén waves are examined in a two-component flat-top distributed plasma. The flat-top distribution affects the DL's strength (as defined by the potential drop) and its associated parallel electric field. Our findings are consistent with previous research on DLs in the Earth's magnetosphere. Additionally, we discuss the implications of our findings on charged particle energization in the separatrix region of the Earth's magnetosphere using MMS data.
