Azimuthal flow bursts in the inner plasma sheet and possible connection with SAPS and plasma sheet earthward flow bursts

L. R. Lyons; Y. Nishimura; B. Gallardo‐Lacourt; M. J. Nicolls; S. Chen; D. L. Hampton; W. A. Bristow; J. M. Ruohoniemi; N. Nishitani; E. F. Donovan; V. Angelopoulos

doi:10.1002/2015ja021023

MMS/Cluster joint measurements at the vicinity of the plasma sheet boundary layer

10.5194/egusphere-egu2020-18357 ◽

2020 ◽

Author(s):

Olivier Le Contel ◽

Alessandro Retino ◽

Alexandra Alexandrova ◽

Thomas Chust ◽

Konrad Steinvall ◽

...

Keyword(s):

Boundary Layer ◽

Plasma Sheet ◽

Cold Plasma ◽

Large Scale ◽

Plasma Sheet Boundary Layer ◽

Electrostatic Waves ◽

Hot Plasma ◽

Short Period ◽

Generation Mechanisms ◽

Earthward Flow

<p>On 28th of August 2018 at 5:30 UT, MMS and Cluster were located in the magnetotail at about 16 earth radii (RE). They both suddenly crossed plasma interfaces. Located in the post midnight sector, Cluster transitioned from a cold plasma sheet to a hot plasma sheet whereas MMS, located at 4 RE duskward of Cluster, transitioned from a similar cold plasma sheet to the lobe region via a very short period in a hot plasma sheet. At 05:50 UT MMS returned to a hot plasma sheet and detected a quasi-parallel earthward flow ~ 400 km/s and increased energetic ion and electron fluxes. We use measurements from both missions during this conjunction to describe the possible macroscale evolution of the magnetotail as well as some associated kinetic processes. In particular, we analyze fast and slow non linear electrostatic waves propagating tailward which are detected in the so called electron boundary layer as well as in the hot plasma sheet. We discuss their possible generation mechanisms and link with the large scale evolution of the magnetotail. Finally, we investigate possible effects related to the dawn-dusk asymmetry of the magnetotail.</p>

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Origin of some anisotropic tailward flows in the plasma sheet

Annales Geophysicae ◽

10.5194/angeo-20-1559-2002 ◽

2002 ◽

Vol 20 (10) ◽

pp. 1559-1575 ◽

Cited By ~ 5

Author(s):

J. A. Wanliss ◽

R. D. Sydora ◽

G. Rostoker ◽

R. Rankin

Keyword(s):

Plasma Sheet ◽

Ion Beam ◽

Particle Model ◽

Ion Distributions ◽

Central Plasma ◽

Nonadiabatic Effects ◽

Equatorial Current ◽

Central Plasma Sheet ◽

Velocity Moments ◽

Earthward Flow

Abstract. We use a test particle model to explore anisotropy and fast flows in the central plasma sheet (CPS) that are a consequence of plasma sheet boundary layer (PSBL) ion beam dynamics. Ion distributions and flows (velocity moments) in the CPS and equatorial current sheet (CS) are compared and we find that mirroring of initially earthward beams from the PSBL, and their subsequent convection to the CS region, results in strong anisotropy throughout the CPS. At higher latitudes, velocity moments are field-aligned and feature earthward flow. Deeper in the CPS, velocity moments yield flows in the anti-earthward direction. There is no clear distinction between the PSBL and CPS, since velocity distributions with large streaming components occur throughout the model CPS, but in the CS region they are anisotropic and nongyrotropic. In the CS region velocity moments can feature anti-earthward cross field flows. These tailward flows (> 400 km/s) are observed in the CS region between X = - 20 to - 30 RE due to nonadiabatic effects. Model results suggest that fast tailward plasma flows can be obtained without necessarily appealing to magnetotail processes associated with dynamic geomagnetic activity.Key words. Magnetospheric physics (magnetospheric con-figuration and dynamics) – Space plasma physics (charge particle motion and acceleration; numerical simulation studies)

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Longitudinal development of a substorm brightening arc

Annales Geophysicae ◽

10.5194/angeo-27-1935-2009 ◽

2009 ◽

Vol 27 (5) ◽

pp. 1935-1940 ◽

Cited By ~ 15

Author(s):

K. Shiokawa ◽

A. Ieda ◽

A. Nakajima ◽

K. Sakaguchi ◽

R. Nomura ◽

...

Keyword(s):

Magnetic Field ◽

Plasma Sheet ◽

Substorm Onset ◽

Pressure Increase ◽

Longitudinal Development ◽

Magnetic Latitude ◽

Longitudinal Extension ◽

Earthward Flow

Abstract. We present simultaneous THEMIS-ground observations of longitudinal (eastward) extension of a substorm initial-brightening arc at Gillam (magnetic latitude: 65.6°) at 08:13 UT on 10 January 2008. The speed of the eastward arc extension was ~2.7 km/s. The extension took place very close to the footprints of the longitudinally separated THEMIS E and D satellites at ~12 RE. The THEMIS satellites observed field dipolarization, weak earthward flow, and pressure increase, which propagated eastward from E to D at a speed of ~50 km/s. The THEMIS A satellite, located at 1.6 RE earthward of THEMIS E, observed fluctuating magnetic field during and after the dipolarization. The THEMIS E/D observations suggest that the longitudinal extension of the brightening arc at substorm onset is caused by earthward flow braking processes which produce field dipolarization and pressure increase propagating in longitude in the near-earth plasma sheet.

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Statistical analysis of earthward flow bursts in the inner plasma sheet during substorms

Journal of Geophysical Research Atmospheres ◽

10.1029/2009ja014275 ◽

2009 ◽

Vol 114 (A7) ◽

pp. n/a-n/a ◽

Cited By ~ 25

Author(s):

Y. D. Ma ◽

J. B. Cao ◽

R. Nakamura ◽

T. L. Zhang ◽

H. Reme ◽

...

Keyword(s):

Statistical Analysis ◽

Plasma Sheet ◽

Earthward Flow

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Plasma sheet fast flows and auroral dynamics during substorm: a case study

Annales Geophysicae ◽

10.5194/angeo-20-341-2002 ◽

2002 ◽

Vol 20 (3) ◽

pp. 341-347 ◽

Cited By ~ 5

Author(s):

N. L. Borodkova ◽

A. G. Yahnin ◽

K. Liou ◽

J.-A. Sauvaud ◽

A. O. Fedorov ◽

...

Keyword(s):

Plasma Sheet ◽

Neutral Line ◽

Filamentary Structure ◽

Storms And Substorms ◽

Flow Directions ◽

Auroral Phenomena ◽

Fast Flow ◽

The Relationship ◽

Earthward Flow

Abstract. Interball-1 observations of a substorm development in the mid-tail on 16 December 1998 are compared with the auroral dynamics obtained from the Polar UV imager. Using these data, the relationship between plasma flow directions in the tail and the location of the auroral activation is examined. Main attention is given to tailward and earth-ward plasma flows, interpreted as signatures of a Near Earth Neutral Line (NENL). It is unambiguously shown that in the mid-plasma sheet the flows were directed tailward when the auroral bulge developed equatorward of the spacecraft ionospheric footprint. On the contrary, when active auroras moved poleward of the Interball-1 projection, earthward fast flow bursts were observed. This confirms the concept that the NENL (or flow reversal region) is the source of auroras forming the poleward edge of the auroral bulge. The observed earthward flow bursts have all typical signatures of Bursty Bulk Flows (BBFs), described by Angelopolous et al. (1992). These BBFs are related to substorm activations starting at the poleward edge of the expanded auroral bulge. We interpret the BBFs as a result of reconnection pulses occurring tail-ward of Interball-1. In addition, some non-typically observed phenomena were detected in the plasma sheet during this substorm: (i) tailward/earthward flows were superimposed on a very strong duskward flow, and (ii) wavy structures of both magnetic field and plasma density were registered. The latter observation is probably linked to the filamentary structure of the current sheet.Key words. Magnetospheric physics (auroral phenomena; plasma sheet; storms and substorms)

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