We present multi spacecraft measurements in the magnetosheath (MSH) and in the solar wind (SW) by Interball, Cluster and Polar, demonstrating that coherent structures with magnetosonic Mach number up ...to 3 - Supermagnetosonic Plasma Streams (SPS) - generate transient and anomalous boundary dynamics, which may cause substantial displacements of the magnetospheric boundaries and the riddling of peripheral boundary layers. In this regard, for the first time, we describe a direct plasma penetration into the flank boundary layers, which is a candidate for being the dominant transport mechanism for disturbed MSH periods. Typically SPS's have a ram pressure exceeding by several times that of the SW and lead to long-range correlations between processes at the bow shock (BS) and at the magnetopause (MP) on one side and between MSH and MP boundary layers on the other side. We demonstrate that SPS's can be observed both near the BS and near the MP and argue that they are often triggered by hot flow anomalies (HFA), which represent local obstacles to the SW flow and can induce the SPS generation as a means for achieving a local flow balance. Finally, we also discuss other causes of SPS's, both SW-induced and intrinsic to the MSH. SPS's appear to be universal means for establishing a new equilibrium between flowing plasmas and may also prove to be important for astrophysical and fusion applications.
Resonant modes with frequencies 0.02–10 mHz are detected from the bow shock (BS) to the outer magnetosphere, with the nature of the resonances at frequencies 0.02–0.25 mHz being still unexplained. ...We propose a BS model in the form of a circular plate free along the outer edge that predicts resonant modes at frequencies 0.02–0.3 mHz or lower. We demonstrate the detection of these model resonant modes based on data from five satellites, with the resonance near 0.1 mHz predicted by the model being observed in the magnetosheath continuously for 17 hours downstream of both parallel and perpendicular shocks. Resonant BS modes produce three-wave nonlinear cascades that realize a broadband coherent coupling with resonances both near and inside the magnetopause. In our opinion, it is the coherent nature of the processes in an extended region with different linear resonant eigenmodes that determines the fairly new, nonlinear-cascade, approach to an efficient conversion of the energy of an inflow when interacting with an obstacle. This seems important for the entire nonlinear physics. We also provide arguments suggesting the possibility of resonant mode self-generation in the closed BS/magnetopause loop with a feedback in the form of narrow Poynting vector pulses at the cost of solar wind energy.
The linear and nonlinear resonances and cascades affecting significantly the interaction of a collisionless plasma flow with a magnetic barrier and the plasma penetration into the barrier are studied ...using the near-Earth magnetopause as an example. Our linear theory of the membrane instability of the boundary of a magnetic barrier, the magnetopause, explains the structure of the spectra and bi-spectra of fluctuations on different segments of the boundary layers near the magnetopause and the resonances at frequencies 0.05–0.5 mHz. The recorded compressibility of waves under the magnetopause implies that their excitation by Alfv’en resonances alone is impossible. We assume, as a general principle, an approximate coincidence of the frequencies of different harmonics of different resonances as a condition for the amplification of resonances to nonlinear amplitudes and their propagation into the ionosphere. We confirm the presence of resonant waves near the magnetopause and demonstrate a nonlinear three-wave cascade interaction of compressible (0.05–5 mHz) and incompressible waves under the magnetopause that provides the excitation of resonances of magnetic field lines and waveguide resonances at frequencies 1–25 mHz without a close coincidence of the frequencies with linear resonances at the magnetopause and the bow shock. This can also provide a nonlinear coupling of linear and nonlinear resonances in other multilayered media (for example, in the plasma and neutral sheets of the geomagnetic tail and between it and the magnetopause). An example of the excitation of a waveguide mode inside the magnetopause by nonlinear membrane waves is given. We have detected a nonlinear excitation and interaction of most “magic” harmonics under the magnetopause.
The statistical features of the magnetic field and ion flux fluctuations in the boundary regions of the Earth’s magnetosphere have been studied on different timescales based on the Interball ...satellite measurements. Changes in the form and parameters of the probability density function have been studied for the periods when the satellite was in the solar wind plasma, different magnetosheath regions, and the turbulent boundary layer (TBL) at the polar cusp outer boundary. Variations in the probability density function maximum (
P
0
) and the kurtosis value as characteristics of the turbulence property evolution on different timescales have been studied. Two asymptotic regimes of
P
0
, which are characterized by different power laws, have been found. The structural functions of different orders and the types of diffusion processes in different regions, depending on time variations in the generalized diffusion coefficient, have been studied in order to analyze the character of diffusion processes. For the magnetosheath regions, TBL, and polar cusp, it has been found that the diffusion coefficient increases in the course of time (i.e., the regime of superdiffusion has been obtained). In the foreshock region before the main shock, turbulent processes are described by the Kolmogorov model of classical diffusion.
A simple and highly efficient method for the rearrangement of bromohydrins mediated by Et2Zn to synthesize carbonyl compounds was described. Various β-bromo alcohols were treated with 0.6 equiv of ...Et2Zn to form a zinc complex in CH2Cl2 at room temperature for 2 h, followed by 1,2-migration to give the corresponding carbonyl compounds. This remarkable and clean rearrangement is general for acyclic and cyclic bromohydrins, and a variety of ring-expansive and -contractive carbonyl compounds were obtained in good to excellent yields according to the feature of the starting bromohydrins. The functional group tolerance of organozinc reagents in this reaction will be useful in organic synthesis. The scope and limitations of this rearrangement process were also investigated.
The scientific rationale of the ROY multi-satellite mission addresses multiscale investigations of plasma processes in the key magnetospheric regions with strong plasma gradients, turbulence and ...magnetic field annihilation in the range from electron inertial length to MHD scales.
The main scientific aims of ROY mission include explorations of:
(a)
turbulence on a non-uniform background as a keystone for transport processes;
(b)
structures and jets in plasma flows associated with anomalously large concentration of kinetic energy; their impact on the energy balance and boundary formation;
(c)
transport barriers: plasma separation and mixing, Alfvenic collapse of magnetic field lines and turbulent dissipation of kinetic energy;
(d)
self-organized versus forced reconnection of magnetic field lines;
(e)
collisionless shocks, plasma discontinuities and associated particle acceleration processes.
In the case of autonomous operation, 4 mobile spacecrafts of about 200
kg mass with 60
kg payload equipped with electro-reactive plasma engines will provide 3D measurements at the scales of 100–10000
km and simultaneous 1D measurements at the scales 10–1000
km. The latter smaller scales will be scanned with the use of radio-tomography (phase-shift density measurements within the cone composed of 1 emitting and 3 receiving spacecrafts).
We also discuss different opportunities for extra measurement points inside the ROY mission for simultaneous measurements at up to 3 scales for the common international fleet.
Combined influence of intermittent turbulence and reconnection on the geomagnetic tail and on the nonlinear dynamics of boundary layers will be explored in situ with fast techniques including particle devices under development, providing plasma moments down to 30
ms resolution.
We propose different options for joint measurements in conjunction with the SCOPE and other missions:
•
simultaneous sampling of low- and high-latitudes magnetopause, bow shock and geomagnetic tail at the same local time;
•
tracing of magnetosheath streamlines from the bow shock to near-Earth geomagnetic tail;
•
passing “through” the SCOPE on the inbound orbit leg;
•
common measurements (with SCOPE and other equatorial spacecraft) at distances of ∼ few thousand km for durations of ∼several hours per orbit.
The orbit options and scientific payload of possible common interest are discussed in this work, including FREGAT cargo opportunities for extra payload launching and the “Swarm” campaigns with ejection of nano- and pico-satellites.
A new and efficient methodology has been developed for the synthesis of β-diketones from aromatic α-bromo ketones in the presence of Furukawa reagent under mild conditions. The present transformation ...is proposed to proceed via a Reformatsky-type reaction of α-bromo ketones, followed by C−C bond sigmatropic rearrangement of the aldolate intermediate to give β-diketones in moderate to good isolated yields, while aliphatic α-bromomethyl ketones resulted in the formation of 2,4-disubstituted furans or cis-1,2-disubstituted cyclopropanols in moderate yields. The scope of this process was investigated, and a tentative mechanism was proposed.
The data on cold ion fluxes measured by the ALPHA 3 instrument on Interball-Tail in July – October 1999 when the spacecraft crossed the dusk side outer plasmasphere, and in January – April 2000 when ...it crossed the dawn side plasmasphere are analyzed. Correlation of cold ion parameters in the plasmasphere with indices of geomagnetic activity and parameters of the external solar wind flow is examined. In the innermost observed part of the dawn plasmasphere ion temperature is increasing with MLT from post midnight to prenoon. In the outermost plasmasphere no temperature dependence on MLT was observed. It is revealed that cold ion density in the dusk and dawn side outer plasmasphere is increasing with increasing solar wind ram pressure.
The paper addresses nonlinear phenomena that control the interaction between plasma flow (solar wind) and magnetic barrier (magnetosphere). For the first time we demonstrate that the dominant solar ...wind kinetic energy: (i) excites boundary resonances and their harmonics which modulate plasma jets under the bow shock; (ii) produces discrete three-wave cascades, which could merge into a turbulent-like one; (iii) jet produced cascades provide the effective anomalous plasma transport inside and out of the magnetosphere; (iv) intermittency and multifractality characteristics for the statistic properties of jets result in a super-ballistic turbulent transport regime. Our results could be considered as suggestive for the space weather predictions, for turbulent cascades in different media and for the laboratory plasma confinement (e.g., for fusion devices).
Number density and temperature of cold H
+ ion fluxes in the plasmasphere measured by the Auroral probe/Alpha 3 experiment during two geomagnetic storms are analyzed. It was found that after the ...onset of geomagnetic storms the plasmapause both on the night and day sides starts moving toward the Earth almost simultaneously. The delay of the beginning of plasmapause movement on the day side relative to the night side is at least much less than the corotation time of magnetic tube with cold plasma from the night sector into the day sector of the plasmasphere. It was found that the number density of cold plasma inside the daytime plasmasphere could significantly change, either decrease or increase, during moderate geomagnetic storms. Now we cannot definitely determine the reason for these variations, but we assume they are caused by variations of parameters (e.g.,
n
max
F
2,
h
max
F
2
) in the underlying ionosphere initiated by geomagnetic storms.
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