scholarly journals Comparative magnetotail flapping: an overview of selected events at Earth, Jupiter and Saturn

2013 ◽  
Vol 31 (5) ◽  
pp. 817-833 ◽  
Author(s):  
M. Volwerk ◽  
N. André ◽  
C. S. Arridge ◽  
C. M. Jackman ◽  
X. Jia ◽  
...  
Keyword(s):  
Current Sheet ◽  
Sheet Thickness ◽  
Minimum Variance ◽  
Giant Planets ◽  
Variance Analysis ◽  
Wave Period ◽  
Unknown Input ◽  
The Earth ◽  
Magnetometer Data ◽  
The Waves

Abstract. A comparison of magnetotail flapping (the up-and-down wavy motion) between the Earth and the two giant planets Jupiter and Saturn has been performed through investigation of the current sheet normal of the magnetotail. Magnetotail flapping is commonly observed in the Earth's magnetotail. Due to single spacecraft missions at the giant planets, the normal is determined through minimum variance analysis of magnetometer data during multiple intervals when the spacecraft crossed through the current sheet. It is shown that indeed a case can be made that magnetotail flapping also occurs at Jupiter and Saturn. Calculations of the wave period using generic magnetotail models show that the observed periods are much shorter than their theoretical estimates, and that this discrepancy can be caused by unknown input parameters for the tail models (e.g., current sheet thickness) and by possible Doppler shifting of the waves in the spacecraft frame through the fast rotation of the giant planets.

scholarly journals Search for oblique Whistler waves using solar orbiter data

2021 ◽  
Author(s):  
Lucas Colomban ◽  
Matthieu Kretzschmar ◽  
Volodya Krasnoselskikh ◽  
Laura Bercic ◽  
Chris Owen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Distribution Function ◽  
Electron Distribution ◽  
Electron Distribution Function ◽  
Minimum Variance ◽  
Frequency Range ◽  
Whistler Waves ◽  
Magnetometer Data ◽  
Halo Population ◽  
The Waves

<p>Whistler waves are thought to play an important role on the evolution of the electron distribution function as a function of distance. In particular, oblique whistler waves may diffuse the Strahl electrons  into the halo population.  Using AC magnetic field from the RPW/SCM (search coil magnetometer) of Solar Orbiter, we search for the presence of oblique Whistler waves in the frequency range between 3 Hz and 128 Hz .  We perform a minimum variance analysis of the SCM data in combination with the MAG (magnetometer) data to determine the inclination of the waves with respect to the ambiant magnetic field. As the emphasis is placed on the search for oblique whistler, we also analyze the RPW electric field data and the evolution of the electron distribution function during these Whistler events.</p>

scholarly journals Forming terrestrial planets and delivering water

2015 ◽  
Vol 11 (A29B) ◽  
pp. 427-430
Author(s):  
Kevin J. Walsh
Keyword(s):  
Planet Formation ◽  
Semimajor Axis ◽  
Giant Planet ◽  
Terrestrial Planet ◽  
Giant Planets ◽  
Asteroid Belt ◽  
Terrestrial Planets ◽  
The Earth ◽  
Building Models ◽  
Rich Material

AbstractBuilding models capable of successfully matching the Terrestrial Planet's basic orbital and physical properties has proven difficult. Meanwhile, improved estimates of the nature of water-rich material accreted by the Earth, along with the timing of its delivery, have added even more constraints for models to match. While the outer Asteroid Belt seemingly provides a source for water-rich planetesimals, models that delivered enough of them to the still-forming Terrestrial Planets typically failed on other basic constraints - such as the mass of Mars.Recent models of Terrestrial Planet Formation have explored how the gas-driven migration of the Giant Planets can solve long-standing issues with the Earth/Mars size ratio. This model is forced to reproduce the orbital and taxonomic distribution of bodies in the Asteroid Belt from a much wider range of semimajor axis than previously considered. In doing so, it also provides a mechanism to feed planetesimals from between and beyond the Giant Planet formation region to the still-forming Terrestrial Planets.

Current sheet thickness of the outer boundary of the magnetosphere as observed by four CLUSTER satellites

2007 ◽  
Vol 45 (3) ◽  
pp. 268-272 ◽  
Author(s):  
E. V. Panov ◽  
S. P. Savin ◽  
J. Büchner ◽  
A. Korth
Keyword(s):  
Current Sheet ◽  
Outer Boundary ◽  
Sheet Thickness

scholarly journals Electric fields and double layers in plasmas

1987 ◽  
Vol 5 (2) ◽  
pp. 233-255 ◽  
Author(s):  
Nagendra Singh ◽  
H. Thiemann ◽  
R. W. Schunk
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Electric Fields ◽  
Sheet Thickness ◽  
High Density ◽  
Effective Length ◽  
Double Layers ◽  
Low Density ◽  
Ambient Magnetic Field ◽  
Cold Plasmas

Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamic features of the double layers are discussed. These features, as seen in simulations, laboratory experiments and theory, indicate that double layers and the currents through them undergo slow oscillations, which are determined by the ion transit time across an effective length of the system in which the double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations have been considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields (parallel to an ambient magnetic field) and double layers in an expanding plasma are discussed.

New Metric for Minimum Variance Analysis Validation in the Study of Interplanetary Magnetic Clouds

Solar Physics ◽  
2020 ◽  
Vol 295 (3) ◽  
Author(s):  
Rosemeire Aparecida Rosa Oliveira ◽  
Marcos William da Silva Oliveira ◽  
Arian Ojeda-González ◽  
Victor De La Luz
Keyword(s):  
Minimum Variance ◽  
Variance Analysis ◽  
Magnetic Clouds

scholarly journals Implementation and Hardware-In-The-Loop Simulation of a Magnetic Detumbling and Pointing Control Based on Three-Axis Magnetometer Data

Aerospace ◽  
2019 ◽  
Vol 6 (12) ◽  
pp. 133 ◽  
Author(s):  
M. Salim Farissi ◽  
Stefano Carletta ◽  
Augusto Nascetti ◽  
Paolo Teofilatto
Keyword(s):  
Attitude Control ◽  
Experimental Testing ◽  
Hardware In The Loop ◽  
Attitude Dynamics ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Magnetic Attitude Control ◽  
Magnetometer Data ◽  
The Subject ◽  
Pointing Control

The subject of this work is the implementation and experimental testing of a purely magnetic attitude control strategy, which can provide stabilization after the deployment and pointing of the spacecraft without any attitude information. In particular, the control produces the detumbling of the satellite and leads it to a desired attitude with respect to the direction of the Earth magnetic field, based on the only information provided by a three-axis magnetometer. The system is meant to be used as a backup solution, in case of failure of the primary strategy and is designed considering the constraints set on time of operations, power consumption, and peak electric current for a typical CubeSat mission. The detumbling and pointing algorithms are implemented on the FPGA core of a CubeSat on-board computer and tested by Hardware-in-the-loop simulations. The simulation setup includes a Helmholtz cage, recreating the magnetic environment along the orbit, the on-board computer, a MEMS three-axis magnetometer and Simulink software, on which the attitude dynamics is propagated. Test on the real system can provide useful information to select the parameters of the control, such as the gains, to estimate the limits of the system, the time of operations and prevent failures.

scholarly journals Magnetic turbulence and particle dynamics in the Earth’s magnetotail

2003 ◽  
Vol 21 (9) ◽  
pp. 1947-1953 ◽  
Author(s):  
G. Zimbardo ◽  
A. Greco ◽  
A. L. Taktakishvili ◽  
P. Veltri ◽  
L. M. Zelenyi
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Sheet Thickness ◽  
Particle Dynamics ◽  
Particle Simulation ◽  
Mhd Waves ◽  
Magnetic Fluctuations ◽  
Magnetic Turbulence ◽  
Magnetospheric Configuration And Dynamics ◽  
Interplanetary Physics

Abstract. The influence of magnetic turbulence in the near-Earth magnetotail on ion motion is investigated by numerical simulation. The magnetotail current sheet is modelled as a magnetic field reversal with a normal magnetic field com-ponent Bn , plus a three-dimensional spectrum of magnetic fluctuations dB which represents the observed magnetic turbulence. The dawn-dusk electric field Ey is also considered. A test particle simulation is performed using different values of Bn and of the fluctuation level dB/B0. We show that when the magnetic fluctuations are taken into account, the particle dynamics is deeply affected, giving rise to an increase in the cross tail transport, ion heating, and current sheet thickness. For strong enough turbulence, the current splits in two layers, in agreement with recent Cluster observations.Key words. Magnetospheric physics (magnetospheric configuration and dynamics) – Interplanetary physics (MHD waves and turbulence) – Electromagnetics (numerical methods)

Development of a database of Jovian magnetodisc crossings by Galileo and Juno spacecraft from magnetometer data

2020 ◽  
Author(s):  
Igor Alekseev ◽  
Elena Belenkaya ◽  
Alexander Lavrukhin ◽  
David Parunakian ◽  
Ivan Pensionerov
Keyword(s):  
Magnetic Field ◽  
Current Sheet ◽  
Polar Axis ◽  
Dipole Axis ◽  
Radial Magnetic Field ◽  
Jovian Magnetosphere ◽  
Central Surface ◽  
Magnetometer Data ◽  
Plasma Measurements ◽  
The Magnetic Field

<p>Jovian magnetosphere has   a huge equatorial plasma disk, which is also known as the current sheet or magnetodisk. This current sheet enlarges the subsolar magnetosphere size more than twice compare to purely planetary dipole magnetosphere. Near to the planet   the magnetodisk is aligned with the magnetic equatorial plane. As consequence of the dipole axis tilted to the polar axis about 10, each of Juno orbits crossed the central surface of the disk current two times during one jovian day (9, 92 hours). Finally, we have  about 1725 current sheet crossings to study the plasma sheet and current sheets structure.</p> <p>In our work we have developed a database of Jovian current sheet crossings, performed by Galileo and Juno spacecraft, which includes magnetic field and plasma measurements. Current sheet crossings were determined using magnetometer data in distant magnetosphere as a region with the magnetic field strength less than the dipole value at the same point and central current sheet position have been marked by boundary between the region with opposite signum of the radial magnetic field component.</p>

The Harris sheet in a dusty plasma

2010 ◽  
Vol 77 (1) ◽  
pp. 31-37 ◽  
Author(s):  
SAMUEL A. LAZERSON
Keyword(s):  
Current Sheet ◽  
Dusty Plasma ◽  
Nonlinear Differential Equations ◽  
Sheet Thickness ◽  
Dusty Plasmas ◽  
Great Utility ◽  
Highly Nonlinear ◽  
Dust Component ◽  
Great Relevance ◽  
A Current

AbstractIn 1962 E. G. Harris published a solution to the problem of a current sheet separating regions of oppositely directed magnetic field in a fully ionized plasma. The resulting solution has become known as the ‘Harris sheet’ and has been of great utility to the plasma physics community. In this paper, the footsteps of Harris are retraced with the addition of a multiply charged massive dust component. A set of highly nonlinear differential equations for a current sheet in a dusty plasma are presented. An analytic solution, similar to that of Harris, is found for the depleted electron regime. This solution is of great relevance to many astrophysical and laboratory dusty plasmas. Current sheet thickness and asymptotic field strength are calculated for various dusty plasma environments.

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