scholarly journals On the altitude dependence of transversely heated O<sup>+</sup> distributions in the cusp/cleft

2004 ◽  
Vol 22 (5) ◽  
pp. 1787-1798 ◽  
Author(s):  
M. Bouhram ◽  
B. Klecker ◽  
W. Miyake ◽  
H. Rème ◽  
J.-A. Sauvaud ◽  
...  
Keyword(s):  
Space Plasma ◽  
Particle Interactions ◽  
Space Plasma Physics ◽  
Ion Outflow ◽  
Oxygen Ion ◽  
Altitude Dependence ◽  
Statistical Studies ◽  
Wave Particle Interactions ◽  
Auroral Phenomena ◽  
First Time

Abstract. The present paper focuses on the altitude dependence of oxygen ion conics in the dayside cusp/cleft region. Here, combining oxygen data from the Akebono, Interball-2 and Cluster satellites allows, for the first time, one to follow the global development of energetic (up to ~10keV) ion outflow over a continuous and broad altitude range up to about 5.5 Earth radii (RE). According to earlier statistical studies, the results are consistent with a height-integrated energization of ions at altitudes up to 3.5 RE. Higher up, the results inferred from Cluster observations put forward evidence of a saturation of both a transverse energization rate and ion gyroradii. We suggest that such results may be interpreted as finite perpendicular wavelength effects (a few tens of km) in the wave-particle interactions. To substantiate the suggestion, we carry out two-dimensional, Monte Carlo simulations of ion conic production that incorporate such effects and limited residence times due to the finite latitudinal extent of the heating region.Key words. Magnetospheric physics (auroral phenomena) – Space plasma physics (charged particle motion and acceleration; wave-particle interactions)

scholarly journals Generation of Bernstein waves by ion shell distributions in the auroral region

2003 ◽  
Vol 21 (4) ◽  
pp. 881-891 ◽  
Author(s):  
P. Janhunen ◽  
A. Olsson ◽  
A. Vaivads ◽  
W. K. Peterson
Keyword(s):  
Space Plasma ◽  
Particle Interactions ◽  
Auroral Region ◽  
Simulation Studies ◽  
Space Plasma Physics ◽  
Phase Velocities ◽  
Bernstein Waves ◽  
Auroral Phenomena ◽  
Auroral Arcs ◽  
The Waves

Abstract. Hot ion shell distributions could possibly contain enough free energy for waves that could power electron energisation above auroral inverted-V regions. Using both linear theory (WHAMP) and two-dimensional electrostatic simulations, we show that ion shell distributions can cause unstable ion Bernstein mode emissions with high temporal growth rates, as well as perpendicular and parallel e-folding distances, that are in accordance with the tranverse dimensions of auroral arcs and the parallel size of the energisation region, respectively. The phase velocities of the waves are in the proper range to give parallel energisation to electrons with a Landau resonance. The simulation shows that about 90% of the energy goes into electrons and 10% goes into cold ion perpendicular heating. An electron heating rate of ~ 80 eV/s is obtained.Key words. Ionosphere (auroral phenomena) – Space plasma physics (numerical simulation studies; wave-particle interactions)

scholarly journals Spectral characteristics of waves and particles in the model of cyclotron wave-particle interactions near plasmapause

1999 ◽  
Vol 17 (3) ◽  
pp. 351-357 ◽  
Author(s):  
D. l. Pasmanik ◽  
V. Y. Trakhtengerts
Keyword(s):  
Spectral Characteristics ◽  
Wave Spectrum ◽  
Energetic Electron ◽  
Space Plasma ◽  
Quantitative Model ◽  
Energetic Particles ◽  
Particle Interactions ◽  
Space Plasma Physics ◽  
Evening Sector ◽  
Wave Particle Interactions

Abstract. Further analysis of energetic electron precipitation at the evening sector of magnetosphere is performed. In the framework of the quantitative model of cyclotron wave-particle interactions developed in the previous Pasmanik et al. paper, the case of finite spread over energies of initial energetic electron distribution is studied. The solution for distribution function of energetic electron is found. The energetic spectrum of trapped and precipitating electrons and whistler wave spectrum are analysed.Key words. Magnetospheric physics (energetic particles · precipitating; energetic particles · trapped); · Space plasma physics (wave-particle interactions).

scholarly journals Richard Mansergh Thorne (1942–2019)

Eos ◽  
2019 ◽  
Vol 100 ◽  
Author(s):  
Richard Horne ◽  
Bruce Tsurutani
Keyword(s):  
Space Plasma ◽  
Radiation Belts ◽  
Particle Interactions ◽  
Low Level ◽  
Complex Wave ◽  
Wave Particle Interactions ◽  
The Way ◽  
Earth's Radiation Belts

A pioneering space plasma physicist who led the way in understanding how complex wave-particle interactions control Earth’s radiation belts and low-level auroral light emissions.

scholarly journals Modeling transverse heating and outflow of ionospheric ions from the dayside cusp/cleft. 1 A parametric study

2003 ◽  
Vol 21 (8) ◽  
pp. 1753-1771 ◽  
Author(s):  
M. Bouhram ◽  
M. Malingre ◽  
J. R. Jasperse ◽  
N. Dubouloz
Keyword(s):  
Residence Time ◽  
Parametric Study ◽  
Large Set ◽  
Particle Interactions ◽  
Ion Heating ◽  
Magnetospheric Convection ◽  
Heating Region ◽  
Altitude Dependence ◽  
Wave Particle Interactions ◽  
Transport Patterns

Abstract. The transport patterns of non-thermal H + and O + field-aligned flows from the dayside cusp/cleft, associated with transverse heating by means of wave-particle interactions and in combination with the poleward motion due to the magnetospheric convection are investigated. This has been accomplished by developing a steady-state, two-dimensional, trajectory-based code. The ion heating is modelled by means of a Monte Carlo technique, via the process of ion cyclotron resonance (ICR), with the electromagnetic left-hand circular polarized component of a broad-band, extremely low-frequency (BBELF) turbulence. The altitude dependence of ICR heating from 1000 km to 3 Earth radii (RE) is modelled by a power law spectrum, with an index a, and a parameter w0 that is proportional to the spectral density at a referenced gyrofrequency. Because of the finite latitudinal extent of the cusp/cleft, the incorporation of the horizontal convection drift leads to a maximum residence time tD of the ions when being energized. A large set of simulations has been computed so as to study the transport patterns of the H + and O + bulk parameters as a function of tD , a, and w0. Residence time effects are significant in O + density patterns while negligible for H +. When comparing the results with analytical one-dimensional theories (Chang et al., 1986; Crew et al., 1990), we find that mean ion energies and pitch angles at the poleward edge of the heating region are slightly influenced by tD and may be used as a probe of ICR parameters ( a, w0). Conversely, poleward of the heating region, upward velocity and mean energy dispersive patterns depend mainly on tD (e.g. the magnitude of the convection drift) with latitudinal profiles varying versus tD . In short, the main conclusion of the paper is that any triplet (tD , a, w0) leads to a unique transport-pattern feature of ion flows associated with a cusp/cleft ionospheric source. In a companion paper, by using high-altitude (1.5–3 RE) ion observations as constraints, the results from the parametric study are used to determine the altitude dependence of transverse ion heating during a significant number of passes of the Interball-2 satellite.Key words. Magnetospheric physics (auroral phenomena) – Space plasma physics (numerical simultation studies; wave-particle interactions)

scholarly journals Comment on "Concerning the generation of geomagnetic giant pulsations by drift-bounce resonance ring current instabilities" by K.-H. Glassmeier et al., Ann. Geophysicae, 17, 338-350, (1999)

2000 ◽  
Vol 18 (2) ◽  
pp. 161-166 ◽  
Author(s):  
I. R. Mann ◽  
G. Chisham
Keyword(s):  
Plasma Physics ◽  
Ring Current ◽  
Space Plasma ◽  
Energetic Particles ◽  
Mhd Waves ◽  
Particle Interactions ◽  
Magnetospheric Physics ◽  
Space Plasma Physics ◽  
Mhd Waves And Instabilities ◽  
Giant Pulsations

Abstract. Not available.Key words: Magnetospheric physics (energetic particles, trapped; MHD waves and instabilities) - Space plasma physics (wave-particle interactions)

scholarly journals Cluster magnetic field observations of the bowshock: Orientation, motion and structure

2001 ◽  
Vol 19 (10/12) ◽  
pp. 1399-1409 ◽  
Author(s):  
T. S. Horbury ◽  
P. J. Cargill ◽  
E. A. Lucek ◽  
A. Balogh ◽  
M. W. Dunlop ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Space Plasma ◽  
Normal Direction ◽  
Field Observations ◽  
Space Plasma Physics ◽  
Combining Data ◽  
Interplanetary Physics ◽  
Magnetic Field Magnitude ◽  
Bow Shocks ◽  
First Time

Abstract. Four spacecraft Cluster magnetic field observations of the low <beta> quasi-perpendicular terrestrial bowshock are presented for the first time. Multiple quasi-perpendicular crossings on 25 December 2000 are analysed. By combining data from the four spacecraft, bowshock orientations and velocities can be calculated. It is shown that, even while in rapid motion, the bowshock normal direction remains remarkably constant, and that coplanarity estimates are accurate to, typically, around 20°. Magnetic field magnitude profiles are shown to be very well correlated between spacecraft although downstream waves with fluctuations perpendicular to the local field, while statistically similar at all four spacecraft, are poorly correlated on separation scales of several hundred km. Examples are shown of a number of bowshock phenomena, including non-standing fluctuations in the shock foot and the shock interacting with changing solar wind conditions.Key words. Interplanetary physics (planetary bow shocks) Space plasma physics (shock waves; waves and instabilities)

scholarly journals Verification of the backward wave oscillator model of VLF chorus generation using data from MAGION 5 satellite

2003 ◽  
Vol 21 (5) ◽  
pp. 1073-1081 ◽  
Author(s):  
E. E. Titova ◽  
B. V. Kozelov ◽  
F. Jiriček ◽  
J. Smilauer ◽  
A. G. Demekhov ◽  
...  
Keyword(s):  
Space Plasma ◽  
Sweep Rate ◽  
Particle Interactions ◽  
Space Plasma Physics ◽  
Frequency Sweep ◽  
Backward Wave Oscillator ◽  
Wave Oscillator ◽  
Backward Wave ◽  
Using Data ◽  
Vlf Emissions

Abstract. We present a detailed study of chorus emissions in the magnetosphere detected on board Magion 5, when the satellite was not far from the magnetic equator. We determine the frequency sweep rate of more than 8500 electromagnetic VLF chorus elements. These results are compared with the backward wave oscillator (BWO) regime of chorus generation. Comparison of the frequency sweep rate with the BWO model shows: (i) There is a correlation between the frequency sweep rates and the chorus amplitudes. The frequency sweep rate increases with chorus amplitude, in accordance with expectations from the BWO model; (ii) The chorus growth rate, estimated from the frequency sweep rate, is in accord with that inferred from the BWO generation mechanism; (iii) The BWO regime of chorus generation ensures the observed decrease in the frequency sweep rate of the chorus elements with increasing L-shell.Key words. Magnetospheric physics (VLF emissions, energetic particles) – Space plasma physics (wave-particle interactions)

scholarly journals The occurrence frequency of upward ion beams in the auroral zone as a function of altitude using Polar/TIMAS and DE-1/EICS data

2003 ◽  
Vol 21 (10) ◽  
pp. 2059-2072 ◽  
Author(s):  
P. Janhunen ◽  
A. Olsson ◽  
W. K. Peterson
Keyword(s):  
Particle Flux ◽  
Ion Beam ◽  
Radial Distance ◽  
Space Plasma ◽  
Auroral Zone ◽  
Ion Beams ◽  
Occurrence Frequency ◽  
Space Plasma Physics ◽  
Wave Heating ◽  
Auroral Phenomena

Abstract. We study the occurrence frequency of upward auroral ion beams as a function of altitude using three years of  Polar/TIMAS ion data combined with 11 years of DE-1/ EICS ion data, in order to reach a complete altitude coverage between 5000 and 30 000 km. The most interesting result is that there is a peak in ion beam occurrence frequency and invariant energy flux and invariant particle flux at ¢ 3 RE radial distance. The peak exists at about the same altitude in both the evening and midnight MLT sectors. No solar cycle effects are found. We suggest that the peak could be due to a preferred altitude of auroral potential structures at ¢ 3 RE . To substantiate the suggestion, we also present a simple Monte Carlo simulation of ion beams. Another result is that the ion beam occurrence frequency and invariant (mapped to ionospheric altitude) energy and particle fluxes increase in the radial distance range 4–6 RE , suggesting that wave heating processes may take place in this altitude range.Key words. Magnetospheric physics (auroral phenomena; magnetosphere-ionosphere interactions) – Space plasma physics (charged particle motion and acceleration)

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