Formation Mechanism of a Strongly Tilted, Knotted Electron Diffusion Region

Identify the physical mechanism that forms a fully three-dimensional, strongly tilted electron diffusion region (knotted EDR) in Earth’s magnetotail reconnection, accounting for the observed large tilt between the EDR and IDR reconnection planes and the concomitant guide-field changes.

Background

The observations reveal an EDR whose reconnection plane is rotated by about 38 degrees relative to the IDR, with a significant increase and directional change in the guide field inside the EDR. While oblique tearing mode instability can tilt current layers, the observed tilt exceeds typical simulation reports, and alternative mechanisms such as electromagnetic drift waves are inconsistent with the event’s characteristics.

Given these discrepancies, the authors note that the specific physical process responsible for producing a strongly tilted, fully three-dimensional knotted EDR under the observed weak guide-field conditions has not been established and requires further paper.