Observation of a Knotted Electron Diffusion Region in Earth's Magnetotail Reconnection
arXiv:2507.10842 · doi:10.1029/2025GL117612
Abstract
Magnetic reconnection is a fundamental plasma process that alters the magnetic field topology and releases magnetic energy. Most numerical simulations and spacecraft observations assume a two-dimensional diffusion region, with the electron diffusion region (EDR) embedded in the same plane as the ion diffusion region (IDR) and a uniform guide field throughout. Using observations from Magnetospheric Multiscale (MMS) mission, we report a non-coplanar, knotted EDR in Earth's magnetotail current sheet. The reconnection plane of the knotted EDR deviates by approximately 38° from that of the IDR, with the guide field exhibiting both a 38° directional shift and a twofold increase in amplitude. Moreover, the Hall magnetic field is bipolar in the EDR but quadrupolar in the IDR, indicating different Hall current structures at electron and ion scales. These observations highlight the importance of three-dimensional effects and illustrate the complexity of multiscale coupling between the EDR and IDR during reconnection studies.1
arXiv comment27 pages and 4 figures
References in corpus (11)
- Electron-Scale Dynamics of the Diffusion Region during Symmetric Magnetic Reconnection in Space
- New Measure of the Dissipation Region in Collisionless Magnetic Reconnection
- Magnetic reconnection in the era of exascale computing and multiscale experiments
- The Effects of Turbulence on Three-Dimensional Magnetic Reconnection at the Magnetopause
- Role of the Plasmoid Instability in Magnetohydrodynamic Turbulence
- Reconnection-Driven Energy Cascade in Magnetohydrodynamic Turbulence
- Comparison of multi-fluid moment models with Particle-in-Cell simulations of collisionless magnetic reconnection
- Global Ten-Moment Multifluid Simulations of the Solar Wind Interaction with Mercury: From the Planetary Conducting Core to the Dynamic Magnetosphere
- The structure of a perturbed magnetic reconnection electron diffusion region
- Orientation and stability of asymmetric magnetic reconnection x-line
- Discovery of double Hall pattern associated with collisionless magnetic reconnection in dusty plasmas