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Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms.

ABSTRACT: We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward/earthward during outward plasma sheet expansion. They coincide with upward field-aligned electron beams with energies of a few hundred eV. These electrons are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.

SUBMITTER: Nakamura R

PROVIDER: S-EPMC5111425 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

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Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms.

Nakamura R R Sergeev V A VA Baumjohann W W Plaschke F F Magnes W W Fischer D D Varsani A A Schmid D D Nakamura T K M TK Russell C T CT Strangeway R J RJ Leinweber H K HK Le G G Bromund K R KR Pollock C J CJ Giles B L BL Dorelli J C JC Gershman D J DJ Paterson W W Avanov L A LA Fuselier S A SA Genestreti K K Burch J L JL Torbert R B RB Chutter M M Argall M R MR Anderson B J BJ Lindqvist P-A PA Marklund G T GT Khotyaintsev Y V YV Mauk B H BH Cohen I J IJ Baker D N DN Jaynes A N AN Ergun R E RE Singer H J HJ Slavin J A JA Kepko E L EL Moore T E TE Lavraud B B Coffey V V Saito Y Y

Geophysical research letters 20160530 10

We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tub ...[more]

PMID: 27867235

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Dataset Information

Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms.

Publications

Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms.

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