INTERBALL magnetotail boundary case studies

Savin, S.; Balan, O.; Бородкова, Н. Л.; Budnik, E. Yu.; Nikolaeva, N. S.; Prokhorenko, V. I.; Pulkkinen, Tuija; Rybjeva, N.; Šafránková, Jana; Sandahl, I.; Amata, E.; Auster, U.; Bellucci, G.; Blăgău, A.; Błȩcki, J.; Buechner, J.; Ciobanu, M.; Dubinin, E.; Yermolaev, Yu. I.; Echim, Marius; Fedorov, A.; Formisano, V.; Grard, R.; Ivchenko, V. N.; Jiřı́ček, F.; Juchniewicz, J.; Климов, С. И.; Korepanov, V. E.; Koskinen, Hannu E. J.; Kudela, K.; Lundin, R.; Lutsenko, V. N.; Marghitu, Octav; Němeček, Zdenek; Nikutowski, B.; Nozdrachev, M. N.; Orsini, S.; Parrot, M.; Petrukovich, A. A.; Pissarenko, N. F.; Романов, С. А.; Rauch, Jean-Louis; Rustenbach, J.; Sauvaud, J. A.; Sarris, E. T.; Skalsky, A.; Šmilauer, J.; Tříska, P.; Trotignon, Jean-Gabriel; Vojta, J.; Zastenker, G. N.; Zelenyǐ, L. M.; Agafonov, Yu. N.; Grushin, V. A.; Khrapchenkov, V. V.; Přech, Lubomír; Santolı́k, O.

doi:10.1016/s0273-1177(97)00508-5

Cited by 12 publications

(10 citation statements)

References 8 publications

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“…Recently, Maynard et al (2001) demonstrated the penetration of the MSH plasma into the tail "sash" in conjunction with the flank TBL. Note that although in Klimov et al (1997) and Savin et al (1997) the TBL-like signatures in the tail have been reported, nobody knew if this TBL is present there more or less permanently. Savin et al (2002a) have demonstrated that a substantial part of the events in those "wings" at the higher latitudes is independent on the interplanetary (IMF) B y , which contradicts the "sash" predictions.…”

Section: The Case On 29 May 1996 On the Background Of Turbulent Boundmentioning

confidence: 97%

“…2. Savin et al (1997Savin et al ( , 1998b demonstrated that intense waves near the lower hybrid frequency (i.e. ∼ several Hz in the TBL) can accelerate electrons along field lines up to the measured energies.…”

Section: Local Versus Remote Mechanisms Of Magnetosheath Plasma Penetmentioning

confidence: 97%

“…It is located just outside and/or at the near cusp magnetopause, and has recently been found to be a permanent feature (Savin et al, 1997(Savin et al, , 1998b(Savin et al, , 2002aKlimov et al, 1997;Sandahl et al, 2000). Here the energy density of the ultra low frequency (ULF) magnetic fluctuations is comparable to the ion kinetic, thermal, and DC magnetic field densities.…”

Section: Introduction and Definitionsmentioning

confidence: 99%

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Magnetosheath-cusp interface

Savin

Zelenyǐ²,

Романов³

et al. 2004

Ann. Geophys.

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Abstract. We advance the achievements of Interball-1 and other contemporary missions in exploration of the magnetosheath-cusp interface. Extensive discussion of published results is accompanied by presentation of new data from a case study and a comparison of those data within the broader context of three-year magnetopause (MP) crossings by Interball-1. Multi-spacecraft boundary layer studies reveal that in ∼80% of the cases the interaction of the magnetosheath (MSH) flow with the high latitude MP produces a layer containing strong nonlinear turbulence, called the turbulent boundary layer (TBL). The TBL contains wave trains with flows at approximately the Alfvén speed along field lines and "diamagnetic bubbles" with small magnetic fields inside. A comparison of the multi-point measurements obtained on 29 May 1996 with a global MHD model indicates that three types of populating processes should be operative:-large-scale (∼few R E ) anti-parallel merging at sites remote from the cusp; -medium-scale (few thousand km) local TBL-merging of fields that are anti-parallel on average;Correspondence to: S. Savin (ssavin@iki.rssi.ru) -small-scale (few hundred km) bursty reconnection of fluctuating magnetic fields, representing a continuous mechanism for MSH plasma inflow into the magnetosphere, which could dominate in quasi-steady cases.The lowest frequency (∼1-2 mHz) TBL fluctuations are traced throughout the magnetosheath from the post-bow shock region up to the inner magnetopause border. The resonance of these fluctuations with dayside flux tubes might provide an effective correlative link for the entire dayside region of the solar wind interaction with the magnetopause and cusp ionosphere. The TBL disturbances are characterized by kinked, double-sloped wave power spectra and, most probably, three-wave cascading. Both elliptical polarization and nearly Alfvénic phase velocities with characteristic dispersion indicate the kinetic Alfvénic nature of the TBL waves. The three-wave phase coupling could effectively support the self-organization of the TBL plasma by means of coherent resonant-like structures. The estimated characteristic scale of the "resonator" is of the order of the TBL dimension over the cusps. Inverse cascades of kinetic Alfvén waves are proposed for forming the larger scale "organizing" structures, which in turn synchronize all nonlinear cascades within the TBL in a self-consistent manner. This infers a qualitative differ-184 S. Savin et al.: Magnetosheath-cusp interface ence from the traditional approach, wherein the MSH/cusp interaction is regarded as a linear superposition of magnetospheric responses on the solar wind or MSH disturbances.

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Section: The Case On 29 May 1996 On the Background Of Turbulent Boundmentioning

confidence: 97%

Section: Local Versus Remote Mechanisms Of Magnetosheath Plasma Penetmentioning

confidence: 97%

Section: Introduction and Definitionsmentioning

confidence: 99%

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Magnetosheath-cusp interface

Savin

Zelenyǐ²,

Романов³

et al. 2004

Ann. Geophys.

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“…Fig. 3 in [A]) can be attributed to the fan instability of the parallel electron flows (see Savin et al, 1997Savin et al, , 1998 and references therein). Taking 10 periods of the low hybrid frequency (10-20 Hz) as a proxy for the time of fan instability development, for the velocity of 100 eV electrons one would get a distance to a source of ∼0.5-1 R E , that corresponds rather to ion time-offlight estimates (that gives the spread of the finite-gyroradius penetration of 2-3 R E , see Fig.…”

Section: Discussionmentioning

confidence: 99%

Experimental study of nonlinear interaction of plasma flow with charged thin current sheets: 2. Hall dynamics, mass and momentum transfer

Savin

Amata

André

et al. 2006

Nonlin. Processes Geophys.

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Abstract.Proceeding with the analysis of Amata et al. (2005), we suggest that the general feature for the local transport at a thin magnetopause (MP) consists of the penetration of ions from the magnetosheath with gyroradius larger than the MP width, and that, in crossing it, the transverse potential difference at the thin current sheet (TCS) is acquired by these ions, providing a field-particle energy exchange without parallel electric fields. It is suggested that a part of the surface charge is self-consistently produced by deflection of ions in the course of inertial drift in the nonuniform electric field at MP.Consideration of the partial moments of ions with different energies demonstrates that the protons having gyroradii of roughly the same size or larger than the MP width carry fluxes normal to MP that are about 20% of the total flow in the plasma jet under MP. This is close to the excess of the ion transverse velocity over the cross-field drift speed in the plasma flow just inside MP (Amata et al., 2005), which conforms to the contribution of the finite-gyroradius inflow across MP. A linkage through the TCS between different plasmas results from the momentum conservation of the Correspondence to: S. Savin (ssavin@iki.rssi.ru) higher-energy ions. If the finite-gyroradius penetration occurs along the MP over ∼1.5 R E from the observation site, then it can completely account for the formation of the jet under the MP. To provide the downstream acceleration of the flow near the MP via the cross-field drift, the weak magnetic field is suggested to rotate from its nearly parallel direction to the unperturbed flow toward being almost perpendicular to the accelerated flow near the MP.We discuss a deceleration of the higher-energy ions in the MP normal direction due to the interaction with finite-scale electric field bursts in the magnetosheath flow frame, equivalent to collisions, providing a charge separation. These effective collisions, with a nonlinear frequency proxy of the order of the proton cyclotron one, in extended turbulent zones are a promising alternative in place of the usual parallel electric fields invoked in the macro-reconnection scenarios. Further cascading towards electron scales is supposed to be due to unstable parallel electron currents, which neutralize the potential differences, either resulted from the ion-burst interactions or from the inertial drift.The complicated MP shape suggests its systematic velocity departure from the local normal towards the average one, inferring domination for the MP movement of the non-local processes over the small-scale local ones.Published by Copernicus GmbH on behalf of the European Geosciences Union and the American Geophysical Union. The measured Poynting vector indicates energy transmission from the MP into the upstream region with the waves triggering impulsive downstream flows, providing an input into the local flow balance and the outward movement of the MP.Equating the transverse electric field inside the MP TCS by the Hall term in the Ohm's law ...

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“…More recently excellent measurement have been made with Geotail (Fujimoto et al, 1997(Fujimoto et al, , 1998 and Interball-1 (Sauvaud et al, 1997;Nemecek et al, 1997;Savin et al, 1997). The structure of the tail LLBL is quite complex and still not fully understood (Fujimoto et al, 1997).…”

Section: Conjugate Measurements Bymentioning

confidence: 99%

First results from the hot plasma instrument PROMICS-3 on Interball-2

Sandahl

Borg

et al. 1999

Ann Geophysicae

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Abstract. The PROMICS-3 instrument on Interball-2 is nominally identical to the PROMICS-3 instrument on Interball-1. It performs three-dimensional measurements of ions in the energy range 4 eV±70 keV with mass separation and of electrons in the energy range 300 eV±35 keV. Interball-2 was launched on August 29, 1996, into an orbit with the same inclination as that of Interball-1, 63, but with apogee at 20 000 km. In this study the PROMICS-3 instrument on Interball-2 is brie¯y described and examples of the ®rst results are presented. Firstly, we report observations of upward moving molecular ions with energies of up to 700 eV at the poleward edge of the auroral oval. Previous observations of out¯owing molecular ions have been at lower altitudes and lower energies. Secondly, we show observations of dawnside magnetosheath plasma injections. Using conjugate data from both PROMICS-3 instruments we have found dispersion structures above the morningside auroral oval, which occurred simultaneously with isolated``pockets'' of magnetosheath plasma at a distance of X GSM À14 to À12 R E , which had been injected into the inner part of the low-latitude boundary layer. These isolated plasma structures were sites of strong ®eld-aligned currents and are proposed to be the magnetospheric counterparts of the dispersion structures.

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INTERBALL magnetotail boundary case studies

Cited by 12 publications

References 8 publications

Magnetosheath-cusp interface

Magnetosheath-cusp interface

Experimental study of nonlinear interaction of plasma flow with charged thin current sheets: 2. Hall dynamics, mass and momentum transfer

First results from the hot plasma instrument PROMICS-3 on Interball-2

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