scholarly journals Auroral source region: Plasma properties of the high-latitude plasma sheet

2003 ◽  
Vol 108 (A10) ◽  
Author(s):  
C. A. Kletzing
Keyword(s):  
High Latitude ◽  
Plasma Sheet ◽  
Source Region ◽  
Plasma Properties ◽  
Region Plasma

Survey of Jupiter’s Plasma Disk from Juno Observations

2021 ◽  
Author(s):  
Fran Bagenal ◽  
Ezra Huscher ◽  
Robert Wilson ◽  
Frederic Allegrini ◽  
Robert Ebert
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Plasma Sheet ◽  
Radial Distance ◽  
Regular Structure ◽  
Plasma Properties ◽  
Density Distributions ◽  
Jovian System ◽  
Structure Density

<p>Using 30 inbound passes through the Jovian system, we combine measurements from the fields and particles instruments on the Juno spacecraft to survey the properties of Jupiter's plasma disk. Juno's orbit is particularly useful for exploring the variation in plasma conditions with latitude as well as radial distance (from ~10 to ~50 RJ). We present basic plasma properties (composition, density, temperature, velocity, magnetic field strength) to make maps of the plasma environment. Also show that on some of the 53-day orbits the plasma sheet has regular structure (density having roughly Gaussian distribution with latitude and decreasing with distance) but there are also highly irregular orbits with low or erratic density distributions.</p>

scholarly journals <i>Letter to the Editor</i> Why do ultra-low-frequency MHD oscillations with a discrete spectrum exist in the magnetosphere?

2005 ◽  
Vol 23 (3) ◽  
pp. 1075-1079 ◽  
Author(s):  
A. S. Leonovich ◽  
V. A. Mazur
Keyword(s):  
Discrete Spectrum ◽  
Observational Data ◽  
High Latitude ◽  
Plasma Sheet ◽  
Low Frequency ◽  
Magnetosonic Wave ◽  
Letter To The Editor ◽  
Morning Sector ◽  
Good Agreement

Abstract. A new concept of the global magnetospheric resonator is suggested for fast magnetosonic waves in which the role of the resonator is played by the near-Earth part of the plasma sheet. It is shown that the magnetosonic wave is confined in this region of the magnetosphere within its boundaries. The representative value of the resonator's eigenfrequency estimated at f~1MHz is in good agreement with observational data of ultra-low-frequency MHD oscillations of the magnetosphere with a discrete spectrum (f~0.8, 1.3, 1.9, 2.6...MHz). The theory explains the ground-based localization of the oscillations observed in the midnight-morning sector of the high-latitude magnetosphere.

scholarly journals Solar wind control of plasma number density in the near-Earth plasma sheet: three-dimensional structure

2008 ◽  
Vol 26 (12) ◽  
pp. 4031-4049 ◽  
Author(s):  
D. Nagata ◽  
S. Machida ◽  
S. Ohtani ◽  
Y. Saito ◽  
T. Mukai
Keyword(s):  
Solar Wind ◽  
Density Dependence ◽  
High Latitude ◽  
Plasma Sheet ◽  
Strong Dependence ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Lower Latitude ◽  
Number Density ◽  
Three Dimensional Structure

Abstract. The plasma number density in the near-Earth plasma sheet depends on the solar wind number density and the north-south component of interplanetary magnetic field (IMF Bz) with time lag and duration of several hours. We examined the three-dimensional structure of such dependences by fitting observations of plasma sheet and solar wind to an empirical model equation. Analyses were conducted separately for northward and southward IMF conditions. Effects of solar wind speed and IMF orientation were also examined by further subdivision of the dataset. Based on obtained results, we discuss (i) the relative contribution of the ionosphere and solar wind to plasma sheet mass supply, (ii) the entry mechanisms for magnetosheath particles, and (iii) the plasma transport in the plasma sheet. We found that solar wind number density dependence is weaker and IMF Bz dependence is stronger for faster solar wind with southward IMF, which suggests the contribution of ionospheric particles. Further from the Earth, different interplanetary conditions result in different structures of solar wind dependence, which indicate different solar wind entry mechanisms: (1) southward IMF results in a strong dependence on solar wind number density in the flank high-latitude region, (2) slow solar wind with northward IMF leads to lower-latitude peaks of solar wind number density dependence in the flank region, (3) fast solar wind with northward IMF results in a strong dependence on solar wind number density at the down-tail dusk flank equator, and (4) solar wind number density dependence is stronger in the downstream of quasi-parallel bow shock. These features are attributable to (1) low-latitude dayside reconnection entry, (2) high-latitude dayside reconnection entry, (3) entry due to decay of Kelvin-Helmholtz vortices, and (4) diffusive entry mediated by kinetic Alfven waves, respectively. Effect of IMF Bz and its time lags show plasma sheet reconfiguration associated with enhanced convective transport under southward IMF. Duration of IMF Bz effect under northward IMF is interpreted in terms of turbulent diffusive transport.

scholarly journals Recirculation of plasma sheet particles into the high-latitude boundary layer

1998 ◽  
Vol 103 (A11) ◽  
pp. 26521-26532 ◽  
Author(s):  
D. C. Delcourt ◽  
J.-A. Sauvaud
Keyword(s):  
Boundary Layer ◽  
High Latitude ◽  
Plasma Sheet

A new particle population near the high-latitude plasma sheet

2001 ◽  
Vol 106 (A12) ◽  
pp. 29669-29682 ◽  
Author(s):  
M. Wilber ◽  
Q. Li ◽  
R. M. Winglee ◽  
G. K. Parks ◽  
M. McCarthy ◽  
...  
Keyword(s):  
High Latitude ◽  
Plasma Sheet ◽  
Particle Population

scholarly journals Cluster EDI convection measurements across the high-latitude plasma sheet boundary at midnight

2001 ◽  
Vol 19 (10/12) ◽  
pp. 1669-1681 ◽  
Author(s):  
J. M. Quinn ◽  
G. Paschmann ◽  
R. B. Torbert ◽  
H. Vaith ◽  
C. E. McIlwain ◽  
...  
Keyword(s):  
Electric Fields ◽  
High Latitude ◽  
Plasma Sheet ◽  
Boundary Region ◽  
Electron Drift ◽  
Polar Cap ◽  
Static Structure ◽  
Boundary Crossings ◽  
Instruments And Techniques ◽  
Using Data

Abstract. We examine two crossings of three Cluster satellites from the polar cap into the high-latitude plasma sheet at midnight local time, using data from the Electron Drift Instrument (EDI). EDI measures the full electron drift velocity in the plane perpendicular to the magnetic field for any field and drift directions. The context of the measured convection velocities is established by their relation to the intense enhancements in 1 keV electrons, also measured by EDI, as the satellites move from the polar cap into the plasma sheet boundary. In both cases presented here, the cross B convection in the polar cap is anti-sunward (toward the nightside plasma sheet) with a small duskward component. As the satellites enter the plasma sheet boundary region, the dawn-dusk convective flow component reverses its sign, and the flow in the meridianal plane (toward the center of the plasma sheet) drops substantially. The relatively stable convection in the polar cap becomes highly variable as the PSBL is encountered. The timing and sequence of the boundary crossings by the Cluster satellites are consistent with a relatively static structure on a time scale of the few minutes in satellite separations. In one of the two events, the plasma sheet boundary has a spatially separate structure that is crossed by the satellites before entering the plasma sheet.Key words. Magnetospheric physics (electric fields; magnetopause, cusp and boundary layers; instruments and techniques)

Mapping of the statistical auroral distribution into the magnetosphere

1994 ◽  
Vol 72 (5-6) ◽  
pp. 266-269 ◽  
Author(s):  
Y. I. Feldstein ◽  
R. D. Elphinstone ◽  
D. J. Hearn ◽  
J. S. Murphree ◽  
L. L. Cogger
Keyword(s):  
Plasma Sheet ◽  
Large Scale ◽  
Source Region ◽  
Central Plasma ◽  
Discrete Structures ◽  
Central Plasma Sheet ◽  
Auroral Emissions ◽  
Auroral Arcs ◽  
Inner Region ◽  
Entry Layer

Statistical auroral distributions are used in combination with an empirical model of the Earth's magnetic field in an attempt to determine the large-scale magnetospheric source regions for various types of auroral luminosity. The narrow ring of structured auroral emissions during magnetically quiet intervals appears to be associated with the inner region of the nightside central plasma sheet and the dayside entry layer. Under active conditions these discrete structures expand to fill the entire central plasma sheet. The high-altitude boundary plasma sheet on the other hand is more likely to be related to diffuse auroral emissions poleward of this "oval" and to high-latitude polar auroral arcs. Under this scenario, the region of the magnetosphere bounded by the inner edge of the tail current sheet, the plasmasphere, and the dayside entry layer is the source region for the most equatorward diffuse auroral precipitation.

scholarly journals Statistical survey of day-side magnetospheric current flow using Cluster observations: magnetopause

2017 ◽  
Vol 35 (3) ◽  
pp. 645-657 ◽  
Author(s):  
Evelyn Liebert ◽  
Christian Nabert ◽  
Christopher Perschke ◽  
Karl-Heinz Fornaçon ◽  
Karl-Heinz Glassmeier
Keyword(s):  
Solar Wind ◽  
High Latitude ◽  
Current Flow ◽  
Fluxgate Magnetometer ◽  
Current Direction ◽  
Plasma Properties ◽  
Close Vicinity ◽  
Magnetometer Data ◽  
Current Densities ◽  
Statistical Survey

Abstract. We present a statistical survey of current structures observed by the Cluster spacecraft at high-latitude day-side magnetopause encounters in the close vicinity of the polar cusps. Making use of the curlometer technique and the fluxgate magnetometer data, we calculate the 3-D current densities and investigate the magnetopause current direction, location, and magnitude during varying solar wind conditions. We find that the orientation of the day-side current structures is in accordance with existing magnetopause current models. Based on the ambient plasma properties, we distinguish five different transition regions at the magnetopause surface and observe distinctive current properties for each region. Additionally, we find that the location of currents varies with respect to the onset of the changes in the plasma environment during magnetopause crossings.

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