scholarly journals Solar Wind Plasma Properties During Ortho-Parker IMF Conditions and Associated Magnetosheath Mirror Instability Response

2021 ◽  
Vol 8 ◽  
Author(s):  
V. Génot ◽  
B. Lavraud
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Wind Plasma ◽  
Streamer Belt ◽  
Plasma Properties ◽  
Parker Spiral ◽  
Mirror Mode ◽  
Categorization Scheme ◽  
The Stability ◽  
Region Plasma

The properties of the solar wind fraction that exhibits an Interplanetary Magnetic Field (IMF) orientation orthogonal to the classical Parker spiral (so-called ortho-Parker) are investigated. We make use of a solar wind plasma categorization scheme, using 10 years of OMNI data, and show that the fractions of the different plasma origins (streamer-belt-origin plasma, coronal-hole-origin plasma, sector-reversal-region plasma and ejecta) identified by this scheme are rather constant when expressed as a function of the IMF orientation whereas the Alfvén Mach number significantly depends on this orientation. This has direct implication on the magnetosheath dynamics and, as an example, the stability of the mirror mode in this compressed plasma is studied thanks to Rankine-Hugoniot anisotropic relations. This study sheds light on previously reported, yet unexplained, observations of a larger occurrence of mirror mode in the magnetosheath downstream of ortho-Parker IMF.

Magnetic Curvature Analysis on Reconnection Related Structures at Earth’s Magnetopause

2020 ◽  
Author(s):  
Yi Qi ◽  
Christopher T. Russell ◽  
Robert J. Strangeway ◽  
Yingdong Jia ◽  
Roy B. Torbert ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Magnetic Reconnection ◽  
Solar Wind Plasma ◽  
Radius Of Curvature ◽  
Plasma Properties ◽  
Magnetospheric Multiscale ◽  
Reconnection Site ◽  
Field Lines ◽  
The Magnetic Field

<p>Magnetic reconnection is a mechanism that allows rapid and explosive energy transfer from the magnetic field to the plasma. The magnetopause is the interface between the shocked solar wind plasma and Earth’s magnetosphere. Reconnection enables the transport of momentum from the solar wind into Earth’s magnetosphere. Because of its importance in this regard, magnetic reconnection has been extensively studied in the past and is the primary goal of the ongoing Magnetospheric Multiscale (MMS) mission. During magnetic reconnection, the originally anti-parallel fields annihilate and reconnect in a thinned current sheet. In the vicinity of a reconnection site, a prominently increased curvature of the magnetic field (and smaller radius of curvature) marks the region where the particles start to deviate from their regular gyro-motion and become available for energy conversion. Before MMS, there were no closely separated multi-spacecraft missions capable of resolving these micro-scale curvature features, nor examining particle dynamics with sufficiently fast cadence.</p><p>In this study, we use measurements from the four MMS spacecraft to determine the curvature of the field lines and the plasma properties near the reconnection site. We use this method to study FTEs (flux ropes) on the magnetopause, and the interaction between co-existing FTEs. Our study not only improves our understanding of magnetic reconnection, but also resolves the relationship between FTEs and structures on the magnetopause.</p>

The small spacecraft with a magnetic sail on high-temperature superconductors

2021 ◽  
pp. 51-61
Author(s):  
Timur Sh. KOMBAEV ◽  
Mikhail K. ARTEMOV ◽  
Valentin K. SYSOEV ◽  
Dmitry S. DEZHIN
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
High Temperature ◽  
Shape Memory ◽  
New Technologies ◽  
High Temperature Superconductors ◽  
Solar Wind Plasma ◽  
Large Area ◽  
Small Spacecraft ◽  
Shape Memory Materials

It is proposed to develop a small spacecraft for an experiment using high-temperature superconductors (HTS) and shape memory materials. The purpose of the experiment is to test a technological capability of creating a strong magnetic field on the small spacecraft using HTS and shape memory materials for deployed large-area structures, and study the magnetic field interaction with the solar wind plasma and the resulting force impact on the small spacecraft. This article is of a polemical character and makes it possible to take a fresh look at the applicability of new technologies in space-system engineering. Key words: high-temperature superconductors, shape memory materials, solar wind, spacecraft.

HelioSwarm: The Nature of Turbulence in Space Plasmas

2021 ◽  
Author(s):  
Harlan Spence ◽  
Kristopher Klein ◽  
HelioSwarm Science Team
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Solar Wind Plasma ◽  
Turbulent Energy ◽  
Space Plasmas ◽  
Plasma Parameters ◽  
Astrophysical Plasmas ◽  
Ion Distributions ◽  
Background Magnetic Field

<p>Recently selected for phase A study for NASA’s Heliophysics MidEx Announcement of Opportunity, the HelioSwarm Observatory proposes to transform our understanding of the physics of turbulence in space and astrophysical plasmas by deploying nine spacecraft to measure the local plasma and magnetic field conditions at many points, with separations between the spacecraft spanning MHD and ion scales.  HelioSwarm resolves the transfer and dissipation of turbulent energy in weakly-collisional magnetized plasmas with a novel configuration of spacecraft in the solar wind. These simultaneous multi-point, multi-scale measurements of space plasmas allow us to reach closure on two science goals comprised of six science objectives: (1) reveal how turbulent energy is transferred in the most probable, undisturbed solar wind plasma and distributed as a function of scale and time; (2) reveal how this turbulent cascade of energy varies with the background magnetic field and plasma parameters in more extreme solar wind environments; (3) quantify the transfer of turbulent energy between fields, flows, and ion heat; (4) identify thermodynamic impacts of intermittent structures on ion distributions; (5) determine how solar wind turbulence affects and is affected by large-scale solar wind structures; and (6) determine how strongly driven turbulence differs from that in the undisturbed solar wind. </p>

scholarly journals Plasma and Magnetic Field Turbulence in the Earth’s Magnetosheath at Ion Scales

2021 ◽  
Vol 7 ◽  
Author(s):  
Liudmila Rakhmanova ◽  
Maria Riazantseva ◽  
Georgy Zastenker
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Wind Plasma ◽  
Bow Shock ◽  
Present Review ◽  
Wind Effects ◽  
Earth’S Bow Shock ◽  
Magnetic Field Turbulence ◽  
Plasma Measurements ◽  
Turbulent Cascade

Crossing the Earth’s bow shock is known to crucially affect solar wind plasma including changes in turbulent cascade. The present review summarizes results of more than 15 years of experimental exploration into magnetosheath turbulence. Great contributions to understanding turbulence development inside the magnetosheath was made by means of recent multi-spacecraft missions. We introduce the main results provided by them together with first observations of the turbulent cascade based on direct plasma measurements by the Spektr-R spacecraft in the magnetosheath. Recent results on solar wind effects on turbulence in the magnetosheath are also discussed.

scholarly journals Magnetometer in-flight offset accuracy for the BepiColombo spacecraft

2020 ◽  
Vol 38 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Daniel Schmid ◽  
Ferdinand Plaschke ◽  
Yasuhito Narita ◽  
Daniel Heyner ◽  
Johannes Z. D. Mieth ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Observation Time ◽  
Space Environment ◽  
Method Performance ◽  
Mode Method ◽  
Magnetometer Data ◽  
Mirror Mode ◽  
Fluctuation Method

Abstract. Recently the two-spacecraft mission BepiColombo launched to explore the plasma and magnetic field environment of Mercury. Both spacecraft, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO, also referred to as Mio), are equipped with fluxgate magnetometers, which have proven to be well-suited to measure the magnetic field in space with high precision. Nevertheless, accurate magnetic field measurements require proper in-flight calibration. In particular the magnetometer offset, which relates relative fluxgate readings into an absolute value, needs to be determined with high accuracy. Usually, the offsets are evaluated from observations of Alfvénic fluctuations in the pristine solar wind, if those are available. An alternative offset determination method, which is based on the observation of highly compressional fluctuations instead of incompressible Alfvénic fluctuations, is the so-called mirror mode technique. To evaluate the method performance in the Hermean environment, we analyze four years of MESSENGER (MErcury Surface, Space ENvironment, GEophysics and Ranging) magnetometer data, which are calibrated by the Alfvénic fluctuation method, and compare it with the accuracy and error of the offsets determined by the mirror mode method in different plasma environments around Mercury. We show that the mirror mode method yields the same offset estimates and thereby confirms its applicability. Furthermore, we evaluate the spacecraft observation time within different regions necessary to obtain reliable offset estimates. Although the lowest percentage of strong compressional fluctuations are observed in the solar wind, this region is most suitable for an accurate offset determination with the mirror mode method. 132 h of solar wind data are sufficient to determine the offset to within 0.5 nT, while thousands of hours are necessary to reach this accuracy in the magnetosheath or within the magnetosphere. We conclude that in the solar wind the mirror mode method might be a good complementary approach to the Alfvénic fluctuation method to determine the (spin-axis) offset of the Mio magnetometer.

Statistical relations between in-situ measured Bz component and thermospheric density variations

2021 ◽  
Author(s):  
Sofia Kroisz ◽  
Lukas Drescher ◽  
Manuela Temmer ◽  
Sandro Krauss ◽  
Barbara Süsser-Rechberger ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Field Measurements ◽  
Satellite Orbit ◽  
Solar Wind Plasma ◽  
Statistical Investigation ◽  
Neutral Density ◽  
Special Focus ◽  
Short Term

<p>Through advanced statistical investigation and evaluation of solar wind plasma and magnetic field data, we investigate the statistical relation between the magnetic field B<sub>z</sub> component, measured at L1, and Earth’s thermospheric neutral density. We will present preliminary results of the time series analyzes using in-situ plasma and magnetic field measurements from different spacecraft in near Earth space (e.g., ACE, Wind, DSCOVR) and relate those to derived thermospheric densities from various satellites (e.g., GRACE, CHAMP). The long and short term variations and dependencies in the solar wind data are related to variations in the neutral density of the thermosphere and geomagnetic indices. Special focus is put on the specific signatures that stem from coronal mass ejections and stream or corotating interaction regions.  The results are used to develop a novel short-term forecasting model called SODA (Satellite Orbit DecAy). This is a joint study between TU Graz and University of Graz funded by the FFG Austria (project “SWEETS”).</p>

Three-dimensional Multispecies Simulation of the Solar Wind Interaction with Mars Under Different Interplanetary Magnetic Field Orientations

2021 ◽  
Vol 921 (2) ◽  
pp. 139
Author(s):  
Yun Li ◽  
Haoyu Lu ◽  
Jinbin Cao ◽  
Shibang Li ◽  
Christian Mazelle ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Three Dimensional ◽  
Polarity Reversal ◽  
Solar Wind Interaction ◽  
Magnetic Structures ◽  
Parker Spiral ◽  
Global Configuration ◽  
Spiral Angle

Abstract Without the intrinsic magnetic field, the solar wind interaction with Mars can be significantly different from the interaction with Earth and other magnetized planets. In this paper, we investigate how a global configuration of the magnetic structures, consisting of the bow shock, the induced magnetosphere, and the magnetotail, is modulated by the interplanetary magnetic field (IMF) orientation. A 3D multispecies numerical model is established to simulate the interaction of solar wind with Mars under different IMF directions. The results show that the shock size including the subsolar distance and the terminator radius increases with Parker spiral angle, as is the same case with the magnetotail radius. The location and shape of the polarity reversal layer and inverse polarity reversal layer in the induced magnetotail are displaced to the y < 0 sector for a nonzero flow-aligned IMF component, consistent with previous analytical solutions and observations. The responses of the Martian global magnetic configuration to the different IMF directions suggest that the external magnetic field plays an important role in the solar wind interaction with unmagnetized planets.

scholarly journals Impact of solar wind depression on the dayside magnetosphere under northward interplanetary magnetic field

2011 ◽  
Vol 29 (1) ◽  
pp. 31-46 ◽  
Author(s):  
S. Baraka ◽  
L. Ben-Jaffel
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Cell Model ◽  
Dynamic Pressure ◽  
Outer Boundary ◽  
Solar Wind Plasma ◽  
Tail Region ◽  
Dayside Magnetopause

Abstract. We present a follow up study of the sensitivity of the Earth's magnetosphere to solar wind activity using a particles-in-cell model (Baraka and Ben Jaffel, 2007), but here during northward Interplanetary Magnetic Field (IMF). The formation of the magnetospheric cavity and its elongation around the planet is obtained with the classical structure of a magnetosphere with parallel lobes. An impulsive disturbance is then applied to the system by changing the bulk velocity of the solar wind to simulate a decrease in the solar wind dynamic pressure followed by its recovery. In response to the imposed drop in the solar wind velocity, a gap (abrupt depression) in the incoming solar wind plasma appears moving toward the Earth. The gap's size is a ~15 RE and is comparable to the sizes previously obtained for both Bz<0 and Bz=0. During the initial phase of the disturbance along the x-axis, the dayside magnetopause (MP) expands slower than the previous cases of IMF orientations as a result of the abrupt depression. The size of the MP expands nonlinearly due to strengthening of its outer boundary by the northward IMF. Also, during the initial 100 Δt, the MP shrank down from 13.3 RE to ~9.2 RE before it started expanding, a phenomenon that was also observed for southern IMF conditions but not during the no IMF case. As soon as they felt the solar wind depression, cusps widened at high altitude while dragged in an upright position. For the field's topology, the reconnection between magnetospheric and magnetosheath fields is clearly observed in both the northward and southward cusps areas. Also, the tail region in the northward IMF condition is more confined, in contrast to the fishtail-shape obtained in the southward IMF case. An X-point is formed in the tail at ~110 RE compared to ~103 RE and ~80 RE for Bz=0 and Bz<0, respectively. Our findings are consistent with existing reports from many space observatories (Cluster, Geotail, Themis, etc.) for which predictions are proposed to test furthermore our simulation technique.

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