Reconnection X‐Line Orientations at the Earth's Magnetopause

• Published in: Journal of geophysical research. Space physics 2021-12, Vol.126 (12), p.n/a
• Main Authors: Fuselier, S. A., Webster, J. M., Trattner, K. J., Petrinec, S. M., Genestreti, K. J., Pritchard, K. R., LLera, K., Broll, J. M., Burch, J. L., Strangeway, R. J.
• Format: Article
• Language: English
• Subjects: cross‐scale coupling; Earth; Earth magnetosphere; Electron diffusion; Interplanetary magnetic field; Magnetic fields; Magnetic reconnection; Magnetopause; Magnetospheric-solar wind relationships; reconnection electron diffusion regions; Solar wind
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2021JA029789

Observations from the magnetospheric multiscale mission in or near electron diffusion regions (EDRs) at the Earth's magnetopause are used to determine the orientation of reconnection X‐lines. The results highlight cross‐scale coupling of magnetic reconnection and the differences between component and anti‐parallel reconnection. These observations are consistent with a model that has a continuous, component reconnection X‐line that extends many Earth Radii (RE) across the dayside magnetopause when the interplanetary magnetic field (IMF) is southward and |BY| ∼ |BZ|. Encounters anywhere along the X‐line have similar cross‐section structure in the direction normal to the magnetopause, indicating that component reconnection is quasi‐two‐dimensional, at some scale larger than the electron scale. EDR encounters far from this primary component X‐line may be associated with transient or spatially limited reconnection structures. On the magnetopause flanks on either side of the component X‐line, there are regions where anti‐parallel reconnection occurs. These regions dominate the entire dayside magnetopause when the IMF is southward and |BY|