SAID: A turbulent plasmaspheric boundary layer

Мишин, Е. В.; Puhl-Quinn, P.; Santolı́k, O.

doi:10.1029/2010gl042929

Cited by 33 publications

(61 citation statements)

References 19 publications

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“…The other model of the SAID formation that needs to be considered in discussing the present observations is short‐circuiting of the substorm‐injected hot jets or plasmoids over the cold plasmasphere followed by a formation of a turbulent boundary layer [ Mishin and Puhl‐Quinn , 2007; Mishin et al , 2010]. This concept was based on magnetically‐conjugate satellite observations in the magnetosphere (Cluster and Polar) and topside ionosphere (DMSP) [ Puhl‐Quinn et al , 2007; Mishin and Puhl‐Quinn , 2007] and related satellite observations of the highly‐irregular structures within the SAPS region called SAPS Wave Structure or SAPS WS [ Mishin et al , 2003; Mishin and Burke , 2005].…”

Section: Discussionmentioning

confidence: 99%

“…The short‐circuiting mechanism explicitly accounts for the charge neutrality requirement and observationally‐established SAID features such as fast formation after substorm onset and earthward/equatorward motion during substorm development. It also successfully accounts for features that are difficult to explain using current or voltage generator scenarios such as FAC closure not through the center of the SAID channel and relative locations of the plasmapause and particle precipitation boundaries that were found in their observations [ Puhl‐Quinn et al , 2007; Mishin and Puhl‐Quinn , 2007; Mishin et al , 2010].…”

Section: Discussionmentioning

confidence: 99%

“…In this model, a distinction is implied between SAID and more extended SAPS, with a reported SAID longitudinal extent of ∼2 hours in MLT about the substorm onset magnetic meridian of ∼22 MLT [ Mishin and Puhl‐Quinn , 2007; Mishin et al , 2010]. These estimates agree reasonably well with the present observations, where the major SAPS intensification started at ∼11:06 UT or ∼21:55 MLT (at MLON = 235°), Figures 1 and 2, and where SAID/SAPS was spanning ∼30° in MLON or 2 hours in MLT, Figure 3.…”

Section: Discussionmentioning

confidence: 99%

“…Alternative ideas include the concept of SAID as an interface region between the substorm injection front and the plasmasphere. The interface processes may involve thermoelectric effects and rotational discontinuity at the interface surface [ De Keyser et al , 1998; De Keyser , 1999] and a short‐circuiting of the injection front over the plasmasphere followed by a turbulent overlap layer formation [ Mishin and Puhl‐Quinn , 2007; Mishin et al , 2010].…”

Section: Introductionmentioning

confidence: 99%

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SAPS intensification during substorm recovery: A multi-instrument case study

et al. 2011

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[1] A case of the major intensification of the subauroral polarization stream (SAPS) during the substorm recovery phase is presented. The continuous high-time-resolution Doppler velocity measurements in the subauroral and auroral regions were conducted with the Unwin HF radar, and these are analyzed in the context of the simultaneous and coincident measurements of the auroral luminosity and the total electron content (TEC) by the IMAGE and GPS satellites. Additional information was provided by other SuperDARN radars, DMSP F15 satellite crossing the fully-developed SAPS region, ground-based measurements near the location of the substorm onset, and GOES and LANL satellites in the inner magnetosphere. The association between the SAPS and TEC trough is further substantiated at short timescales and TEC is shown to exhibit two distinct types of responses to substorm onset poleward of and within SAPS, with no evidence of a TEC decrease during SAPS intensification. It is argued that the positive feedback between the electric fields and electron densities was probably not responsible for the observed SAPS intensification. Moreover, it is proposed that the strong and steady plasma acceleration within SAPS may be triggered by a burst of auroral activity, rather than accompanied by a similarly steady variation in other observed parameters either in the ionosphere or in the inner magnetosphere. It is also argued that the SAPS intensification occurring during the recovery phase is not necessarily expected from the current models of the SAPS formation and evolution, but is consistent with the observationally-based view of a fully-developed SAPS as a substorm recovery phenomenon.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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SAPS intensification during substorm recovery: A multi-instrument case study

et al. 2011

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“…There were examples both of plasmoids with a higher velocity, in the anti-sunward direction, than the surrounding magnetosheath plasma and of plasmoids moving with the same velocity as that plasma. A related process has been observed on the nightside, where a sub-auroral ion drift channel is formed when the plasma sphere short circuits a plasmoid, which has been injected in connection with a substorm 34 .…”

Section: Introductionmentioning

confidence: 99%

Plasma penetration of the dayside magnetopause

et al. 2012

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Data from the Cluster spacecraft during their magnetopause crossing on 25 January 2002 are presented. The magnetopause was in a state of slow non-oscillatory motion during the observational period. Coherent structures of magnetosheath plasma, here typified as plasmoids, were seen on closed magnetic field lines on the inside of the magnetopause. Using simultaneous measurements on two spacecraft the inward motion of the plasmoids is followed from one spacecraft to the next, and it is found to be in agreement with the measured ion velocity. The plasma characteristics and the direction of motion of the plasmoids show that they have penetrated the magnetopause, and the observations are consistent with the concept of impulsive penetration, as it is known from theory, simulations, and laboratory experiments. The mean flux across the magnetopause observed was 0.2-0.5% of the solar wind flux at the time, and the peak values of the flux inside the plasmoids reached approximately 20% of the solar wind flux.

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Fine structure of subauroral electric field and electron content

Makarevich

Bristow

2014

JGR Space Physics

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Citation:Makarevich, R. A., and W. A. Bristow (2014) Abstract Small-scale structure of the plasma convection and electron content within the subauroral polarization stream (SAPS) is investigated. We present ionospheric observations during the main phase of the geomagnetic storm on 17 March 2013, during which a sequence of intense, highly localized, and fast-moving electric field (EF) structures within SAPS was observed by the Super Dual Auroral Radar Network Christmas Valley West (CVW) radar. The CVW EF measurements at 60 s resolution are analyzed in context of coincident GPS measurements of the total electron content (TEC) at 30 s resolution. The strong and narrow feature of the subauroral ion drift (SAID) was observed poleward of the TEC trough, with a TEC enhancement (peak) seen in the SAPS (SAID) region. The SAPS wave activity commenced ∼2 h (15 min) after first appearance of SAPS (SAID). The SAPS structures appeared near the poleward edge of the trough, propagated westward, and merged with SAID near TEC peak. The propagation velocity was comparable with convection velocity within each EF structure. The SAPS TEC exhibited a general decrease toward the end of the period. On a smaller time scale, TEC exhibited a small but appreciable decrease within EF structures. The wavelet spectra of EF and TEC showed similar variations, with wave period of ∼5 min period near onset and increasing to 8-10 min toward the end of the period with significant wave activity. A scenario is discussed, in which the SAPS wave activity may modify the ionospheric conductance and TEC at small scales, with large-scale magnetosphere-ionosphere feedback acting to continuously deplete TEC where/when such activity does not occur.

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SAID: A turbulent plasmaspheric boundary layer

Cited by 33 publications

References 19 publications

SAPS intensification during substorm recovery: A multi-instrument case study

SAPS intensification during substorm recovery: A multi-instrument case study

Plasma penetration of the dayside magnetopause

Fine structure of subauroral electric field and electron content

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