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Energy Conversion and Partition in the Asymmetric Reconnection Diffusion RegionWe investigate the energy conversion and partition in the asymmetric reconnection diffusion region using two-dimensional particle-in-cell simulations and Magnetosphere Multiscale (MMS) mission observations. Under an upstream condition with equal temperatures in the two inflow regions, the simulation analysis indicates that the energy partition between ions and electrons depends on the distance from the X-line. Within the central electron diffusion region (EDR), nearly all dissipated electromagnetic field energies are converted to electrons. From the EDR to the ion diffusion region (IDR) scales, the rate of the electron energy gain decreases to be lower than that of ions. A magnetopause reconnection event inside the IDR observed by MMS shows comparable ion and electron energy gains, consistent with the simulation result in the transition region from EDR to IDR. At the EDR scale, the electron energization is mainly by the reconnection electric field (E(sub r)); in-plane electric fields (E(sub xz)) provide additional positive contributions near the X-line and do negative work on electrons beyond the EDR. The guide field reduces the electron energization by both E(sub r) and E(sub xz) in the EDR. For ion energization, E(sub r) and E(sub xz) have comparable contributions near the time of the peak reconnection rate, while E(sub xz) dominants at later time. At the IDR scale, the guide field causes asymmetry in the amount of the energy gain and energization mechanisms between two exhausts but does not have significant effects on energy partition. Our study advances understanding of ion and electron energization in asymmetric reconnect IDRs.
Document ID
20190002422
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Wang, Shan
(Maryland Univ. College Park, MD, United States)
Chen, Li-Jen
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Bessho, Naoki
(Maryland Univ. Baltimore County (UMBC) Baltimore, MD, United States)
Hesse, Michael
(Maryland Univ. College Park, MD, United States)
Yoo, Jongsoo
(Princeton Plasma Physics Lab. Princeton, NJ, United States)
Yamada, Masaaki
(Princeton Plasma Physics Lab. Princeton, NJ, United States)
Liu, Yi-Hsin
(Dartmouth Coll. Hanover, NH, United States)
Gershman, Daniel J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Giles, Barbara L.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Moore, Thomas E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
April 11, 2019
Publication Date
October 13, 2018
Publication Information
Publication: Journal of Geophysical Research: Space Physics
Publisher: American Geophysical Union
Volume: 123
Issue: 10
ISSN: 2169-9402
e-ISSN: 2169-9380
Subject Category
Physics (General)
Report/Patent Number
GSFC-E-DAA-TN66022
Funding Number(s)
CONTRACT_GRANT: NNG11PL02A
CONTRACT_GRANT: AGS-1202537
CONTRACT_GRANT: AGS-1552142
CONTRACT_GRANT: AGS-1543598
CONTRACT_GRANT: DESC001627
Distribution Limits
Public
Copyright
Use by or on behalf of the US Gov. Permitted.
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