| Title: |
Electron Dynamics Within the Electron Diffusion Region of Asymmetric Reconnection |
| Authors: |
Argall, M. R.; Paulson, K.; Alm, L.; Rager, A.; Dorelli, J.; Shuster, J.; Wang, S.; Torbert, R. B.; Vaith, H.; Dors, I.; Chutter, M.; Farrugia, C.; Burch, J.; Pollock, C.; Giles, B.; Gershman, D.; Lavraud, B.; Russell, C. T.; Strangeway, R.; Magnes, W.; Lindqvist, P. -A; Khotyaintsev, Yuri V.; Ergun, R. E.; Ahmadi, N. |
| Publisher Information: |
Uppsala universitet, Institutet för rymdfysik, Uppsalaavdelningen; Univ New Hampshire, Ctr Space Sci, Durham, NH USA; NASA, Goddard Space Flight Ctr, Greenbelt, MD USA; Univ New Hampshire, Ctr Space Sci, Durham, NH USA; Southwest Res Inst, San Antonio, TX USA; Southwest Res Inst, San Antonio, TX USA; Univ Toulouse, CNRS, Inst Rech Astrophys & Planetol, UPS, Toulouse, France.; Univ Calif Los Angeles, Earth Planetary & Space Sci, Los Angeles, CA USA.; Austrian Acad Sci, Space Res Inst, Graz, Austria; KTH Royal Inst Technol, Stockholm, Sweden; Univ Colorado Boulder, Boulder, CO USA |
| Publication Year: |
2018 |
| Collection: |
Uppsala University: Publications (DiVA) |
| Subject Terms: |
Fusion; Plasma and Space Physics; plasma och rymdfysik |
| Description: |
We investigate the agyrotropic nature of electron distribution functions and their substructure to illuminate electron dynamics in a previously reported electron diffusion region (EDR) event. In particular, agyrotropy is examined as a function of energy to reveal detailed finite Larmor radius effects for the first time. It is shown that the previously reported approximate to 66eV agyrotropic "crescent" population that has been accelerated as a result of reconnection is evanescent in nature because it mixes with a denser, gyrotopic background. Meanwhile, accelerated agyrotropic populations at 250 and 500eV are more prominent because the background plasma at those energies is more tenuous. Agyrotropy at 250 and 500eV is also more persistent than at 66eV because of finite Larmor radius effects; agyrotropy is observed 2.5 ion inertial lengths from the EDR at 500eV, but only in close proximity to the EDR at 66eV. We also observe linearly polarized electrostatic waves leading up to and within the EDR. They have wave normal angles near 90 degrees, and their occurrence and intensity correlate with agyrotropy. Within the EDR, they modulate the flux of 500eV electrons travelling along the current layer. The net electric field intensifies the reconnection current, resulting in a flow of energy from the fields into the plasma. Plain Language Summary: The process of reconnection involves an explosive transfer of magnetic energy into particle energy. When energetic particles contact modern technology such as satellites, cell phones, or other electronic devices, they can cause random errors and failures. Exactly how particles are energized via reconnection, however, is still unknown. Fortunately, the Magnetospheric Multiscale mission is finally able to detect and analyze reconnection processes. One recent finding is that energized particles take on a crescent-shaped configuration in the vicinity of reconnection and that this crescent shape is related to the energy conversion process. In our paper, we explain why the ... |
| Document Type: |
article in journal/newspaper |
| File Description: |
application/pdf |
| Language: |
English |
| Relation: |
Journal of Geophysical Research - Space Physics, 2169-9380, 2018, 123:1, s. 146-162; ISI:000425637600012 |
| DOI: |
10.1002/2017JA024524 |
| Availability: |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-348788; https://doi.org/10.1002/2017JA024524 |
| Rights: |
info:eu-repo/semantics/openAccess |
| Accession Number: |
edsbas.351383BD |
| Database: |
BASE |