We present an overview, based on satellite observations at low Earth orbits, on electromagnetic radiation from ground power transmission lines at an industrial frequency 50–60 Hz. Particular attention has been given to Chibis-M and DEMETER satellite observations. The electric 40-cm antenna of the micro-satellite often recorded 50–60 Hz radiation (known as Power Line Emission (PLE)) when it flew over industrialized areas of the planet. The PLE spectral amplitude varied from 1.2 to 18 (μV/m)/Hz0.5, which corresponds to the electric field amplitude E~1 μV/m. We report results of numerical calculations of the electromagnetic response of the atmosphere and ionosphere to a large-scale surface emitter at a frequency of 50 Hz. According to simulation results, PLE with an intensity of ~1 μV/m observed on satellites in the nightside ionosphere at midlatitudes can be excited by an unbalanced current 8–10 A in a power transmission line above the earth's crust with conductivity of 10–3 S/m. At middle and low latitudes with an inclined geomagnetic field, the maximum response in the upper ionosphere to the transmission line radiation should be seen shifted equatorward, although this shift is less than that upon guidance by the geomagnetic field. The maximum amplitude of the electromagnetic response of the ionosphere to the power transmission line emission decreases for an inclined geomagnetic field, but insignificantly. To date, the PLE intensity in near-Earth space has turned out to be higher than the intensity of natural radiation in this range (Schumann resonances and ion whistlers), and continues to grow with the technological development of mankind.

A peculiar feature of geomagnetic variations at middle/low latitudes in the ULF band, just below the fundamental tone of the Schumann resonance, is the occurrence of a multi-band spectral resonant structure, observed by high-sensitivity induction magnetometers during nighttime. The occurrence of such spectral structure was commonly attributed to the Ionospheric Alfvén Resonator (IAR) in the upper ionosphere. Rather surprisingly, while ground observations of the IAR are ubiquitous, there are practically no reports on the IAR signatures from space missions. According to the new paradigm, the multi-band spectral structure excited by a lightning discharge is in fact produced by a regular sequence of an original pulse from a stroke and echo-pulses reflected from the IAR upper boundary. Upon the interaction of initial lightning-generated pulse with the anisotropic lower ionosphere, it partially penetrates into the ionosphere, travels up the ionosphere as an Alfvén pulse, and reflects back from the upper IAR boundary. The superposition of the initial pulse and echo-pulses produces spectra with multiple spectral peaks. Our modeling of Alfvénic pulse propagation in a system with the altitude profile of Alfven velocity modeling the realistic ionosphere has shown that IAR spectral signatures are to be evident only on the ground and above the IAR. Inside the IAR, the superposition of upward and downward propagating pulses produces a more complicated spectral pattern and the IAR spectral signatures deteriorate. We have used electric field data from the low-orbit Chibis-M microsatellite to search for IAR signatures in the ionosphere. We found evidence that the multi-band structure revealed by spectral analysis in the frequency range of interest is indeed the result of a sequence of lightning-produced pulses. According to the proposed conception it seems possible to comprehend why the IAR signatures are less evident in the ionosphere than on the ground.

We tried to find with the ULF/ELF electric field sensor onboard Chibis-M microsatellite signatures of the IAR (Ionospheric Alfvén Resonator) and Schumann resonance (SR) in the upper ionosphere. Whereas observations of the IAR and SR multi-band emissions with ground magnetometers are ubiquitous, in-situ satellite observations of their signatures are very rare. ULF events detected by the Chibis-M show a possibility of triggered excitation of IAR. In contrast to dominating view, IAR has been found to be effectively excited on the dayside, too. Chibis-M observations also supported the possibility of the SR leakage into the upper ionosphere.

Wave and plasma measurements carried out by the Phobos-2 spacecraft in the Martian environment indicate that a part of solar wind electrons and ions are reflected and accelerated at the Martian bow shock. These particles streaming back into the solar wind lead to the formation of the foreshock region upstream the planetary bow shock. It is shown that the general structure of the foreshock at Mars is similar to that of the foreshock region upstream the Earth's bow shock. However, the electric emissions observed at frequencies around 100 Hz at the leading edge of electron foreshock at Mars have been never reported for observations in the similar region at Earth. The burst of these waves occurs before the spacecraft enters the electron foreshock identified with the onset of electron plasma waves and calculations of the magnetic connection to the planetary bow shock.

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 superballistic 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).

This chapter contains sections titled: Introduction Three-Dimensional Resistive MHD Simulations of Magnetotail Reconnection Three-Dimensional Kinetic Simulations of Reconnection Observations Discussion and Summary

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] D 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 similar to few thousand km for durations of similar to 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. (C) 2010 Elsevier Ltd. All rights reserved.

One of the recent challenges of space physics is the study of processes taking place during lightning discharges. A dedicated microsatellite named Chibis-M (<< lapwing >> in English) is under preparation for launch in 2010. It contains two space instrumentation units, namely, << Thunderstorm >> and << Wave Package >>. A special efficiency of this project is expected because not only direct observations of lightnings, but also the synchronized study of wave processes caused by lightnings will be carried out both onboard the satellite and at ground support stations. This will give unprecedented opportunity for monitoring the development of the lightning mechanism from the lightning generation till relaxation in the form of electromagnetic waves. Measurements of electric and magnetic fields and electric current density will be performed within the framework of the wave experiment onboard Chibis-M. Special attention focusses on the ULF - VLF frequency range. The waves of this range play the major role in the interactions of the << magnetosphere - ionosphere - atmosphere - lithosphere >> system and their study is essential for the understanding of these interactions. The project scientific goals and Wave Package onboard instrumentation are described.

High energy density jets in the magnetosheath near the Earth magnetopause were observed by Interball-1 [1]. In this paper, we continue the investigation of this important physical phenomenon. New data provided by Cluster show that the magnetosheath kinetic energy density during more than one hour exhibits an average level and a series of peaks far exceeding the kinetic energy density in the undisturbed solar wind. This is a surprising finding because the kinetic energy of the upstream solar wind in equilibrium should be significantly diminished downstream in the magnetosheath due to plasma braking and thermalization at the bow shock. We suggest resolving the energy conservation problem by the fact that the nonequilibrium jets appear to be locally superimposed on the background equilibrium magnetosheath, and, thus, the energy balance should be settled globally on the spatial scales of the entire dayside magnetosheath. We show that both the Cluster and Interball jets are accompanied by plasma superdiffusion and suggest that they are important for the energy dissipation and plasma transport. The character of the jet-related turbulence strongly differs from that of known standard cascade models. We infer that these jets may represent the phenomenon of the general physical occurrence observed in other natural systems, such as heliosphere, astrophysical, and fusion plasmas [2–10].

The main purposes of experiment “Obstanovka” (“Environment” in Russian) consisting of several instruments are to measure a set of electromagnetic and plasma phenomena characterizing the space weather conditions, and to evaluate how such a big and highly energy consuming body as the International Space Station disturbs the surrounding plasma, and how the station itself is charged due to the operation of so many instruments, solar batteries, life supporting devices, etc. Two identical Langmuir electrostatic probes are included in the experiment “Obstanovka”. In this paper the Langmuir probes for “Obstanovka” experiment are described, including the choice of geometry (spherical or cylindrical), a more reliable method for the sweep voltage generation, an adaptive algorithm for the probe’s operation. Special attention is paid to the possibility for remote upgrading of the instrument from the ground using the standard communication channels.

Exploration of plasma–plasma interactions at the high-latitude magnetopause versus a simulated sheared current sheet with strong fluctuations of realistic spectral shape, revealed a new type of dynamic equilibrium, in which nonlinear disturbances serve as an effective obstacle for 80% of the incident magnetosheath ions, providing also the exchange by ∼10% of plasma particles with the stagnant high-beta boundary layer in the minimum field region over the polar cusps. The measured waves, reflected upstream by the boundary, interact in the 3-wave manner with the magnetosonic (MS) fluctuations of the incident flow, resulting in their amplification and then decay into accelerated MS-jets and Alfven waves, driving decelerated flows at the Alfven speed. This impulsive momentum loss via the MS-jets contributes in the average flow bend around the magnetosphere. The leading jet appearance is suggested to be phase-synchronized with both the initial MS fluctuations and nonlinear cascades upstream at the magnetopause, which constitutes the wavy obstacle with multiple decays into the smaller MS-jets and Alfvenic flows.High dynamic pressure in the MS-jets does not fit their acceleration by a reconnection; instead the jets are able to initiate the driven reconnection in the process of interaction with a downstream magnetopause. The acceleration of the MS-jets is consistent with a Fermi-type mechanism, in which electric wave-trains play the role of a moving non-continuous ‘wall’. Estimations of the jet scales from the approach of a nonlinear Cherenkov resonance conforms 2–3 reflections of the jet from the ‘wall’ before overcoming the ‘wall’ potential barrier.We demonstrate quantitative agreement of the acceleration of the leading MS-jet in the process of inertial ion drift in variable electric fields. Current sheets, generated due to opposite sign of the ion and electron inertial drift, can account for the intermittency of the TBL fluctuations.

We present both statistical and case studies of magnetosheath interaction with the high-latitude magnetopause on the basis of Interball-1 and other ISTP spacecraft data. We discuss those data along with recently published results on the topology of cusp-magnetosheath transition and the roles of nonlinear disturbances in mass and energy transfer across the high-latitude magnetopause. For sunward dipole tilts, a cusp throat is magnetically open for direct interaction with the incident flow that results in the creation of a turbulent boundary layer (TBL) over an indented magnetopause and downstream of the cusp. For antisunward tilts, the cusp throat is closed by a smooth magnetopause; demagnetized ‘plasma balls’ (with scale ∼ few RE, an occurrence rate of ∼25% and trapped energetic particles) present a major magnetosheath plasma channel just inside the cusp. The flow interacts with the ‘plasma balls’ via reflected waves, which trigger a chaotization of up to 40% of the upstream kinetic energy. These waves propagate upstream of the TBL and initiate amplification of the existing magnetosheath waves and their cascade-like decays during downstream passage throughout the TBL. The most striking feature of the nonlinear interaction is the appearance of magnetosonic jets, accelerated up to an Alfvenic Mach number of 3. The characteristic impulsive local momentum loss is followed by decelerated Alfvenic flows and modulated by the TBL waves; momentum balance is conserved only on time scales of the Alfvenic flows (1/fA ∼12 min). Wave trains at fA∼1.3 mHz are capable of synchronizing interactions throughout the outer and inner boundary layers. The sonic/Alfvenic flows, bounded by current sheets, control the TBL spectral shape and result in non-Gaussian statistical characteristics of the disturbances, indicating the fluctuation intermittency. We suggest that the multi-scale TBL processes play at least a comparable role to that of macro-reconnection (remote from or in the cusp) in solar wind energy transformation and population of the magnetosphere by the magnetosheath plasma. Secondary micro-reconnection constitutes a necessary chain at the small-scale (∼ion gyroradius) edge of the TBL cascades. The thick TBL transforms the flow energy, including deceleration and heating of the flow in the open throat, ‘plasma ball’ and the region downstream of the cusp.

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 RE) anti-parallel merging at sites remote from the cusp; medium-scale (few thousandkm) local TBL-merging of fields that are anti-parallel on average; small-scale (few hundredkm) 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 (∼1–2mHz) 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 difference 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. Key words. Magnetospheric physics (magnetopause, cusp, and boundary layers) – Space plasma physics (turbulence; nonlinear phenomena)

Multi-spacecraft tracing of the high latitude magnetopause (MP) and boundary layers and Interball-1 statistics indicate that:(a) The turbulent boundary layer (TBL) is a persistent feature in the region of the cusp and 'sash', a noticeable part of the disturbances weakly depends on the interplanetary magnetic field By component; TBL is a major site for magnetosheath (MSH) plasma penetration inside the magnetosphere through percolation and local reconnection.(b) The TBL disturbances are mainly inherent with the characteristic kinked double-slope spectra and, most probably, 3-wave cascading. The bi-spectral phase coupling indicates self-organization of the TBL as the entire region with features of the non-equilibrium multi-scale and multi-phase system in the near-critical state.(c) We've found the different outer cusp topologies in summer/winter periods: the summer cusp throat is open for the decelerated MSH flows, the winter one is closed by the distant MP with a large-scale (similar toseveral Re) diamagnetic 'plasma ball' inside the MP; the 'ball' is filled from MSH through patchy merging rather than large-scale reconnection.(d) A mechanism for,the-energy release and mass inflow is the local TBL reconnection, which operates at the larger scales for the average anti-parallel fields and at the smaller scales for the nonlinear fluctuating fields; the latter is operative throughout the TBL. The remote from TBL anti-parallel reconnection seems to happen independently. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

The results of low-energy (<1MeV) protons investigation near geomagnetic equator (Lless than or equal to1.15) at different Altitudes are presented. Used data from Active satellite (1989-1991, altitude 500-2500, inclination 820, protons with energy E-p=50 - 500 keV). The proton spectra were obtained during absolute quiet period (-301.04. The characters of proton distributions with energies E-p>100 keV and E-p<100 keV are strongly different. There are features of altitude distribution connected with geomagnetic activity level: during quiet time at night hours all energy protons registered at all altitudes, at day hours the most intensive proton fluxes of were registered at 700-900 km; during disturbed time at night hours they are absent at 900-1100 km, whereas at day hours the essential high-energy proton fluxes appears only at 700 km (C) 2002 Published by Elsevier Science Ltd on behalf of COSPAR.

We study properties of nonlinear magnetic fluctuations in the turbulent boundary layer (TBL) over polar cusps during a typical TBL crossing on 19 June 1998. Interball-1data in the summer TBL are compared with that of Geotail in solar wind (SW) and Polar in the northern TBL. In the TBL two characteristic slopes are seen: ~ - 1 at (0.004- 0.08) Hz and ~ - 2.2 at (0.08-2) Hz. We present evidences that random current sheets with features of coherent solitons can result in: (i) slopes of ~ - 1 in the magnetic power spectra; (ii) demagnetization of the SW plasma in "diamagnetic bubbles"; (iii) nonlinear, presumably, 3-wave phase coupling with cascade features; (iiii) departure from the Gaussian statistics. We discuss the above TBL properties in terms of intermittency and self-organization of nonlinear systems, and compare them with kinetic simulations of reconnected current sheet at the nonlinear state. Virtual satellite data in the model current sheet reproduce valuable cascade-like spectral and bi-spectral properties of the TBL turbulence.

Highlights are presented from studies of the electric field data from various regions along the CLUS- TER orbit. They all point towards a very high coherence for phenomena recorded on four spacecraft that are sepa- rated by a few hundred kilometers for structures over the whole range of apparent frequencies from 1 mHz to 9 kHz. This presents completely new opportunities to study spatial- temporal plasma phenomena from the magnetosphere out to the solar wind. A new probe environment was con- structed for the CLUSTER electric field experiment that now produces data of unprecedented quality. Determination of plasma flow in the solar wind is an example of the capability of the instrument.

The polar cusp being a region of the free access of the solar wind into the inner magnetosphere is also the site of turbulent plasma flow. Satellites Interball Tail probe and Prognoz-8 with their orbits with apogee about 30RE and an inclination of 65° crossed the polar cusps many times. Magion-4 being the subsatellite for Interball-1 (Tail Probe) had the same orbit as the main satellite. In this presentation we discuss results of measurements the spectra of magnetic field fluctuations in the frequency range 30–2000Hz registered onboard Magion-4. During many crossings of the outer polar cusp the broad band emissions, lower hybrid and electron cyclotron harmonics were registered. The correlation of these emissions with plasma spectra is also presented.