Details

Autor(en) / Beteiligte

• Payne, D. S.
• Genestreti, K. J.
• Germaschewski, K.
• Argall, M. R.
• Torbert, R. B.
• Dors, I.
• Ardakani, A.

Titel

Energy Balance and Time Dependence of a Magnetotail Electron Diffusion Region

Ist Teil von

• Journal of geophysical research. Space physics, 2020-11, Vol.125 (11), p.n/a

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• We examine the 11 July 2017 electron diffusion region (EDR)observed by the MagnetosphericMultiscale (MMS) mission using Poynting's theorem. The terms in Poynting's theorem are determined using a linear gradient approximation to obtain barycentric averages within the MMS tetrahedron. We find that Poynting's theorem is approximately balanced in the EDR and the balance is improved if the calculation of ∇·S→ is restricted to the LN plane. The work rate per unit volume J→·E→ is mostly balanced by the divergence of the electromagnetic energy flux ∇·S→, indicating that the electromagnetic energy density remains relatively constant within the EDR during the encounter. We also use particle‐in‐cell (PIC) simulations to examine Poynting's theorem near an x line evolving in time. The central EDR in the simulation is characterized by approximate time independent balance in Poynting's theorem during reconnection growth, while the outer EDR exhibits time‐dependent fluctuations indicative of more chaotic behavior. Key Points We use MMS to evaluate the terms in Poynting's theorem within an electron diffusion region Small imbalance in Poynting's theorem results likely due to the calculation of out‐of‐plane Poynting flux The central EDR is characterized by a time‐independent balance; this is also true for a simulated time‐evolving x line