Magnetospheric Multiscale Observations of Turbulence-Driven Reconnection in Earth’s Magnetosheath
Presentation Type
Talk
Presenter Format
Virtual Meeting Talk
Topic
Dayside Science
Start Date
10-5-2022 10:30 AM
Abstract
Observations of Earth’s magnetosheath from the Magnetospheric Multiscale (MMS) mission have provided an unprecedented opportunity to examine the detailed structure of the multitude of thin current sheets that are generated by plasma turbulence, revealing that a novel form of magnetic reconnection, which has come to be known as electron-only reconnection, can occur within magnetosheath turbulence. Electron-only reconnection events occur at thin electron-scale current sheets and have super-Alfvénic electron outflows that can approach the electron Alfvén speed; however, they do not appear to have signatures of ion outflows. As such the presence of electron-only can potentially have implications for both the nonlinear behavior of the turbulence and the partition of energy between ions and electrons in turbulent dissipation. In this talk, we discuss a recent survey of 256 turbulence-driven magnetic reconnection events observed across 60 intervals of turbulence in the dayside magnetosheath by MMS. We examine the structure of the electric and magnetic fields and the particles within the reconnecting current sheets and demonstrate how the structure of the reconnection events are influenced by the magnetic correlation length of the turbulence, which constrains the length of current sheets formed by the turbulence environment, leading to electron-only reconnection.
Magnetospheric Multiscale Observations of Turbulence-Driven Reconnection in Earth’s Magnetosheath
Observations of Earth’s magnetosheath from the Magnetospheric Multiscale (MMS) mission have provided an unprecedented opportunity to examine the detailed structure of the multitude of thin current sheets that are generated by plasma turbulence, revealing that a novel form of magnetic reconnection, which has come to be known as electron-only reconnection, can occur within magnetosheath turbulence. Electron-only reconnection events occur at thin electron-scale current sheets and have super-Alfvénic electron outflows that can approach the electron Alfvén speed; however, they do not appear to have signatures of ion outflows. As such the presence of electron-only can potentially have implications for both the nonlinear behavior of the turbulence and the partition of energy between ions and electrons in turbulent dissipation. In this talk, we discuss a recent survey of 256 turbulence-driven magnetic reconnection events observed across 60 intervals of turbulence in the dayside magnetosheath by MMS. We examine the structure of the electric and magnetic fields and the particles within the reconnecting current sheets and demonstrate how the structure of the reconnection events are influenced by the magnetic correlation length of the turbulence, which constrains the length of current sheets formed by the turbulence environment, leading to electron-only reconnection.
