Publication Date:
2016-06-07
Description:
We report MMS observations of macroscopic and electron-scale current layers in asymmetric reconnection. By inter-comparing plasma, magnetic and electric field data at multiple crossings of a reconnecting magnetopause on Oct 22, 2015, when the average inter-spacecraft separation was ~10 km, we demonstrate that the ion and electron moments are sufficiently accurate to provide reliable current density measurements at 30 ms cadence. These measurements, which resolve current layers narrower than the inter-spacecraft separation, reveal electron-scale filamentary Hall currents and electron vorticity within the reconnection exhaust far downstream of the X-line and even in the magnetosheath. Slightly downstream of the X-line, intense (up to 3 μA/m 2 ) electron currents, a super-Alfvénic outflowing electron jet, and non-gyrotropic crescent shape electron distributions were observed deep inside the ion-scale magnetopause current sheet and embedded in the ion diffusion region. These characteristics are similar to those attributed to the electron dissipation/diffusion region around the X-line.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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