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We present a detailed analysis of magnetic bubbles observed by the Polar satellite in the high-latitude magnetopause boundary. The bubbles which represent holes or strong depressions (up to 98%) of the ambient magnetic field axe filled with heated solar w

Addresses: Stasiewicz K, Swedish Inst Space Phys, Box 537, SE-75121 Uppsala, Sweden. Swedish Inst Space Phys, SE-75121 Uppsala, Sweden.

We demonstrate that satellite observations of intense transverse ion energization could be explained by stochastic ion heating on short perpendicular wavelength electrostatic waves and structures produced by the decay of dispersive Alfven waves (DAW) This

This paper presents a comprehensive review of dispersive Alfven waves in space and laboratory plasmas. We start with linear properties of Alfven waves and show how the inclusion of ion gyroradius, parallel electron inertia, and finite frequency effects mo, Addresses: Stasiewicz K, Swedish Inst Space Phys, Uppsala, Sweden. Swedish Inst Space Phys, Uppsala, Sweden. CALTECH, Pasadena, CA 91125 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 US

This paper presents a comprehensive review of dispersive Alfven waves in space and laboratory plasmas. We start with linear properties of Alfven waves and show how the inclusion of ion gyroradius, parallel electron inertia, and finite frequency effects mo, Addresses: Stasiewicz K, Swedish Inst Space Phys, S-75591 Uppsala, Sweden. Swedish Inst Space Phys, S-75591 Uppsala, Sweden. Polish Acad Sci, Space Res Ctr, PL-01237 Warsaw, Poland. Serv Sci Ambassade France Suede, St Maur, France. CNRS, CETP, St Maur, Fr

An alternative form of the nonrelativistic permittivity tensor for a homogeneous magnetized plasma in thermal equilibrium is derived in the linear approximation. The derivation follows the lines of Trubnikov's derivation of the relativistic permittivity t, Addresses: Khotyaintsev Y, Swedish Inst Space Phys, S-75591 Uppsala, Sweden. Swedish Inst Space Phys, S-75591 Uppsala, Sweden. Royal Inst Technol, Alfven Lab, S-10044 Stockholm, Sweden.

We demonstrate that satellite observations of intense transverse ion energization could be explained by stochastic ion heating on short perpendicular wavelength electrostatic waves and structures produced by the decay of dispersive Alfven waves (DAW) This mechanism is related to the chaotization of ion orbits which leads to strong stochastic heating when the electric field gradient fulfills the inequality partial derivative E-x/partial derivative x > Omega B-0 (here Omega is the ion gyrofrequency and B-0 is the ambient magnetic field). We also show that the energy sourer for this process is provided from dissipation of the Poynting flux of DAW. which appear to form an energy cascade from large scales lambda(perpendicular to) similar to kilometers down to lambda(perpendicular to) similar to 50 m where the dissipation through the ion heating is observed., QC 20100525

Recent sounding rockets observations highlight some space-time ambiguities in phenomena taking place in the auroral ionosphere, previously observed by the Freja spacecraft. Field aligned electron populations with energies from a few tens of eV to a few keV streaming through cold background plasma are usually observed in the auroral zone in association with strongly nonlinear electromagnetic perturbations. Simultaneous observations of bursty Langmuir emissions indicate the unstable character of these plasma distributions. A detailed analysis shows that the electromagnetic perturbations take the form of quasi-stationary nonlinear spatial structures related to inertial Alfven waves. We suggest that inhomogeneous altitude distribution of the parallel electric field of these structures due to ionospheric density gradientis responsible for the observed electron distributions., QC 20100525

Deep, very narrow magnetic-field-aligned density depletions were observed by the Freja spacecraft during auroral oval crossings. These cavities have perpendicular width of the order of the Electron skin depth c/omega(pe) and are associated with low-freque, Addresses: Bellan PM, CALTECH, Pasadena, CA 91125 USA. CALTECH, Pasadena, CA 91125 USA. Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden.

High time resolution data collected by the Freja spacecraft in the topside ionosphere (h similar to 1500 km) reveal that the "low-frequency turbulence" observed commonly below the ion gyrofrequency consists of a large number of coherent plasma structures, Addresses: Stasiewicz K, Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden. Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.

Multiscale structure of field-aligned currents and plasma density records are analyzed with multiresolution wavelet technique. We show that field-aligned currents measured by Freja in the auroral region have a spectrum of scales from similar to 500 km dow, Addresses: Stasiewicz K, Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden. Swedish Inst Space Phys, Uppsala Div, S-75591 Uppsala, Sweden. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.

The electric-field and wave experiment (EFW) on Cluster is designed to measure the electric-field and density fluctuations with sampling rates up to 36 000 samples s(-1). Langmuir probe sweeps can also be made to determine the electron density and temperature. The instrument has several important capabilities. These include (1) measurements of quasi-static electric fields of amplitudes lip to 700 mV m(-1) with high amplitude and time resolution, (2) measurements over short periods of time of up to five simualtaneous waveforms (two electric signals and three magnetic signals from the seach coil magnetometer sensors) of a bandwidth of 4 kHz with high time resolution, (3) measurements of density fluctuations in four points with high time resolution. Among the more interesting scientific objectives of the experiment are studies of nonlinear wave phenomena that result in acceleration of plasma as well as large- and small-scale interferometric measurements. By using four spacecraft for large-scale differential measurements and several Langmuir probes on one spacecraft for small-scale interferometry, it will be possible to study motion and shape of plasma structures on a wide range of spatial and temporal scales. This paper describes the primary scientific objectives of the EFW experiment and the technical capabilities of the instrument., NR 20140805

Multiresolution wavelet analysis of magnetic field, electric field, and plasma density records taken on Freja during strong auroral events shows evidence for cavity Alfven resonators in the topside ionosphere. The cavity (or transverse) resonators consist, Addresses: Stasiewicz K, SWEDISH INST SPACE PHYS, S-75591 UPPSALA, SWEDEN. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771. ROYAL INST TECHNOL, S-10044 STOCKHOLM, SWEDEN. JOHNS HOPKINS UNIV, APPL PHYS LAB, LAUREL, MD 20723.

We have analyzed complete spectrum of waves (0-4 MHz) and electron distributions during events of modulated Langmuir waves observed by Freja in the topside polar ionosphere. Modulated Langmuir waves are observed with amplitudes 1-1000 mV/m in association, Addresses: Stasiewicz K, SWEDISH INST SPACE PHYS, S-75591 UPPSALA, SWEDEN. JET PROPULS LAB, PASADENA, CA 91109. CORNELL UNIV, DEPT ELECT ENGN, ITHACA, NY 14853. LAB PHYS & CHEM ENVIRONM, ORLEANS, FRANCE.

We present a study of the plasma sheet structure as seen on VIKING during prolonged periods of magnetic quiescence. The ion and electron spectrograms, the electric field data and field-aligned current signatures in the magnetic field data are examined. A special attention is paid to cases when the Low Latitude Boundary Layer-like plasma is seen deep in the nightside at latitudes which apparently map to close geocentric distances as it implies an exotic plasma circulation in the tail. An attempt has been made to infer from VIKING data how the quiet plasma sheet is formed, whether it originates mainly from the mantle source via the interaction with the distant tail current sheet or whether the lateral transport of the Low Latitude Boundary Layer (LLBL) from the tail flanks (with essentially adiabatic particle motion) takes place followed by the sunward convection in the central part of the near-Earth tail. The VIKING plasma and electric field data suggest that the last mechanism is decisive for plasma sheet structuring during prolonged periods of northward IMF., QC 20170123