Flux Transport and Plasma Parameters: Distinguishing Spatial Artifacts from Temporal Signatures of Electron-Only Reconnection
Presentation Type
Talk
Presenter Format
In Person Meeting Talk
Topic
Nightside Science
Start Date
11-5-2022 1:15 PM
Abstract
Magnetic reconnection is a ubiquitous process in solar and magnetospheric plasmas and the origin of explosive phenomena across the Solar System. A new type of reconnection driven solely by electron kinetics, dubbed electron-only (EO) reconnection, was recently observed in Earth’s magnetosphere. Subsequent 2D particle-in-cell (PIC) simulations displayed that EO reconnection in Earth’s magnetotail can quickly arise from a quiet, non-reconnecting current sheet and transition into an ion-coupled, reconnecting current sheet. An important question stemming from these results is: How can one distinguish an EO reconnection observation from a fortuitous, N-directed crossing of a traditionally reconnecting electron diffusion region (EDR), where ion response is relatively obscured? In this study, we use MMS data to survey Earth’s magnetotail for EO reconnection events, EDRs, and Ion Diffusion Regions (IDRs). We find that ions are significantly heated relative to the surrounding plasma sheet in both the IDR and the EDR, but not in EO reconnection, regardless of spacecraft trajectory. In addition, we find that the plasma density within the IDR and EDR decreases at the current sheet center for L-directed orbits and remains constant at the current sheet center for N-directed orbits, while EO reconnection consistently displays increased plasma density. We also calculate the flux transport velocity of EO reconnection events to test if it is consistent with previously confirmed diffusion regions. These features are consistent with the picture of electron-only reconnection as a transition phase from a quiet current sheet to traditional reconnection described in previously mentioned PIC simulations.
Flux Transport and Plasma Parameters: Distinguishing Spatial Artifacts from Temporal Signatures of Electron-Only Reconnection
Magnetic reconnection is a ubiquitous process in solar and magnetospheric plasmas and the origin of explosive phenomena across the Solar System. A new type of reconnection driven solely by electron kinetics, dubbed electron-only (EO) reconnection, was recently observed in Earth’s magnetosphere. Subsequent 2D particle-in-cell (PIC) simulations displayed that EO reconnection in Earth’s magnetotail can quickly arise from a quiet, non-reconnecting current sheet and transition into an ion-coupled, reconnecting current sheet. An important question stemming from these results is: How can one distinguish an EO reconnection observation from a fortuitous, N-directed crossing of a traditionally reconnecting electron diffusion region (EDR), where ion response is relatively obscured? In this study, we use MMS data to survey Earth’s magnetotail for EO reconnection events, EDRs, and Ion Diffusion Regions (IDRs). We find that ions are significantly heated relative to the surrounding plasma sheet in both the IDR and the EDR, but not in EO reconnection, regardless of spacecraft trajectory. In addition, we find that the plasma density within the IDR and EDR decreases at the current sheet center for L-directed orbits and remains constant at the current sheet center for N-directed orbits, while EO reconnection consistently displays increased plasma density. We also calculate the flux transport velocity of EO reconnection events to test if it is consistent with previously confirmed diffusion regions. These features are consistent with the picture of electron-only reconnection as a transition phase from a quiet current sheet to traditional reconnection described in previously mentioned PIC simulations.
