Effects of Electron Vortices on the Magnetic Structures in the Terrestrial Magnetosheath

• Published in: Geophysical research letters Vol. 51; no. 5
• Main Authors: Wang, Z., Huang, S. Y., Yuan, Z. G., Jiang, K., Wu, H. H., Xu, S. B., Wei, Y. Y., Zhang, J., Xiong, Q. Y., Lin, R. T.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 16-03-2024; Wiley
• Subjects: Compression; Correlation; Current sheets; Electric field; Electric fields; Electrons; Energy dissipation; Energy exchange; Evolution; Magnetic field; Magnetic fields; Magnetic flux; Magnetosheath; Magnetospheres; Particle beams; Ropes; Space plasmas; Structures; Vortices; Vorticity
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL106615

Electron vortices are usually embedded within different magnetic structures in space plasmas. The effects, including the nonideal electric field, energy dissipation and magnetic field, of electron vortices on these magnetic structures are still unclear. Utilizing the unprecedented high‐resolution data from the Magnetospheric Multiscale mission in the terrestrial magnetosheath, we statistically investigate these effects on magnetic structures. Both nonideal electric fields and energy dissipation have no obvious correlations with the scales of electron vortices. However, compared to the scales, stronger correlations are found between the vorticities of electron vortices and nonideal electric fields, and energy dissipation, respectively. Most of electron vortices have positive contributions to magnetic fields of magnetic structures, such as strengthening the decrease (or increase) of Bt for current sheets and magnetic holes (or flux ropes and magnetic peaks). Our results reveal that the electron vortices play an important role in the evolution of magnetic structures.
Plain Language Summary
The magnetosheath exhibits various dynamical features such as heating and compression of the plasma, kinetic instabilities, particle beams and kinetic structures due to the highly dynamical environment in near‐Earth space. The electron vortices as the structure that manifests the in suit observations, including bipolar variations of electron velocity and large electron vorticity, have been revealed widely in the magnetosheath. However, the specific effects of electron vortices embedded within the magnetic structures on these magnetic structures are still unknown, especially in a statistical view. Thanks to the unprecedented high‐time resolution data of the Magnetospheric Multiscale mission in the magnetosheath, we investigated the effects, including the nonideal electric fields, energy dissipation and magnetic fields, of electron vortices on these magnetic structures. We find that the nonideal electric fields, energy dissipation inside the electron vortices is more significant than outside for most of magnetic structures, and more than half of electron vortices have positive effects on generating the measured magnetic field of these magnetic structures, which is helpful for understanding the subsequent evolution and interaction between them.
Key Points
The effects of nonideal electric field, energy dissipation and magnetic field of electron vortices on magnetic structures have been studied
The nonideal electric fields and energy dissipation are more correlated with the vorticities of electron vortices compared to their scales
Most of electron vortices have positive contributions to magnetic fields of magnetic structures