The solar wind between 0.1 and 1 AU: Parker Solar Probe - BepiColombo radial alignment and BepiColombo - ACE magnetic alignment

2021 ◽  
Author(s):  
Tommaso Alberti ◽  
Anna Milillo ◽  
Daniel Heyner ◽  
Lina Z. Hadid

<p>At the beginning of September 2020 ACE and BepiColombo spent several hours in an interesting magnetically connected configuration, while at the end of the same month Parker Solar Probe (PSP) and BepiColombo were radially aligned. Being PSP orbiting near 0.1 AU, BepiColombo near 0.6 AU, and ACE at 1 AU, these geometries are of particular interest for investigating the evolution of solar wind properties at different heliocentric distances by observing the same solar wind plasma parcels.<span class="Apple-converted-space"> </span></p> <p>In this contribution we use magnetic field observations from pairs of spacecraft to characterize both the topology of the magnetic field at different heliocentric distances (scalings and high-order statistics) and how it evolves when moving from near-Sun to far-Sun locations. We observe a breakdown of the statistical self-similar nature of the solar wind plasma due to an increase of the intermittency level when moving away from the Sun. These results support previous evidences on the radial dependence of solar wind scaling behavior and can open a novel framework for modeling magnetic field topological changes across the Heliosphere.</p>

2020 ◽  
Author(s):  
Yi Qi ◽  
Christopher T. Russell ◽  
Robert J. Strangeway ◽  
Yingdong Jia ◽  
Roy B. Torbert ◽  
...  

<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>


2018 ◽  
Vol 614 ◽  
pp. A132 ◽  
Author(s):  
S. Fatemi ◽  
N. Poirier ◽  
M. Holmström ◽  
J. Lindkvist ◽  
M. Wieser ◽  
...  

Aims. The lack of an upstream solar wind plasma monitor when a spacecraft is inside the highly dynamic magnetosphere of Mercury limits interpretations of observed magnetospheric phenomena and their correlations with upstream solar wind variations. Methods. We used AMITIS, a three-dimensional GPU-based hybrid model of plasma (particle ions and fluid electrons) to infer the solar wind dynamic pressure and Alfvén Mach number upstream of Mercury by comparing our simulation results with MESSENGER magnetic field observations inside the magnetosphere of Mercury. We selected a few orbits of MESSENGER that have been analysed and compared with hybrid simulations before. Then we ran a number of simulations for each orbit (~30–50 runs) and examined the effects of the upstream solar wind plasma variations on the magnetic fields observed along the trajectory of MESSENGER to find the best agreement between our simulations and observations. Results. We show that, on average, the solar wind dynamic pressure for the selected orbits is slightly lower than the typical estimated dynamic pressure near the orbit of Mercury. However, we show that there is a good agreement between our hybrid simulation results and MESSENGER observations for our estimated solar wind parameters. We also compare the solar wind dynamic pressure inferred from our model with those predicted previously by the WSA-ENLIL model upstream of Mercury, and discuss the agreements and disagreements between the two model predictions. We show that the magnetosphere of Mercury is highly dynamic and controlled by the solar wind plasma and interplanetary magnetic field. In addition, in agreement with previous observations, our simulations show that there are quasi-trapped particles and a partial ring current-like structure in the nightside magnetosphere of Mercury, more evident during a northward interplanetary magnetic field (IMF). We also use our simulations to examine the correlation between the solar wind dynamic pressure and stand-off distance of the magnetopause and compare it with MESSENGER observations. We show that our model results are in good agreement with the response of the magnetopause to the solar wind dynamic pressure, even during extreme solar events. We also show that our model can be used as a virtual solar wind monitor near the orbit of Mercury and this has important implications for interpretation of observations by MESSENGER and the future ESA/JAXA mission to Mercury, BepiColombo.


The first spacecraft encounter with a comet took place on 11 September 1985 when the International Cometary Explorer spacecraft passed through the tail of Comet Giacobini-Zinner at a distance of 7800 km from the nucleus. It provided the first definitive in-situ information concerning the interaction of a cometary atmosphere with the flowing solar-wind plasma, and the results of initial analyses are reviewed in this paper. Large-scale mhd aspects of the interaction largely conform to prior expectation. The flow surrounding the comet is mass-loaded and slowed by situ ionization and pick-up of heavy cometary neutrals, and the solar-wind magnetic field consequently becomes draped around the obstacle, and forms an induced magnetotail. Substantial evidence exists for the permanent presence of a weak shock lying in the subsolar mass-loaded region upstream from the comet, through whether the spacecraft itself passed through shocks on the cometary flanks remains controversial. There is no doubt, however, that a sharp boundary was observed both inbound and outbound (centred on ca. 09h29 and 12h20 U.T.) whose width is an energetic heavyion Larmor radius ( ca. 10 4 km), where the flow is deflected away from the comet and slowed, and where the magnetic field and plasma become compressed and very turbulent. The location of this boundary is also consistent with that expected for a weak shock based upon the known Giacobini-Zinner water-molecule production rate. An unexpected feature of the interaction was the extreme levels of field and plasma turbulence, and broadband wave activity observed in the region of massloaded flow.


1994 ◽  
Vol 144 ◽  
pp. 155-157
Author(s):  
S. Gibson ◽  
F. Bagenal

AbstractWe have modelled the large-scale magnetic field and density structures in the corona using the magnetostatic model of Bogdan and Low (1986) and white light images from both NASA’s Solar Maximum Mission (SMM) Coronagraph/Polarimeter and the High Altitude Observatory Mark III (MkIII) K-coronameter (Bagenal and Gibson, 1991; Gibson and Bagenal, 1992.)We have used the magnetostatic model to calculate the magnetic field, density, pressure, and temperature distribution in the corona. Moreover, we have studied how, if at all, photospheric magnetic field observations could be used to improve predictions of coronal fields.We are at present examining the implications of our predictions of magnetic field and density structures have for coronal heating and solar wind acceleration. We are also analysing the robustness of these predictions, studying both observational and model related errors.


2005 ◽  
Vol 23 (2) ◽  
pp. 609-624 ◽  
Author(s):  
K. E. J. Huttunen ◽  
J. Slavin ◽  
M. Collier ◽  
H. E. J. Koskinen ◽  
A. Szabo ◽  
...  

Abstract. Sudden impulses (SI) in the tail lobe magnetic field associated with solar wind pressure enhancements are investigated using measurements from Cluster. The magnetic field components during the SIs change in a manner consistent with the assumption that an antisunward moving lateral pressure enhancement compresses the magnetotail axisymmetrically. We found that the maximum variance SI unit vectors were nearly aligned with the associated interplanetary shock normals. For two of the tail lobe SI events during which Cluster was located close to the tail boundary, Cluster observed the inward moving magnetopause. During both events, the spacecraft location changed from the lobe to the magnetospheric boundary layer. During the event on 6 November 2001 the magnetopause was compressed past Cluster. We applied the 2-D Cartesian model developed by collier98 in which a vacuum uniform tail lobe magnetic field is compressed by a step-like pressure increase. The model underestimates the compression of the magnetic field, but it fits the magnetic field maximum variance component well. For events for which we could determine the shock normal orientation, the differences between the observed and calculated shock propagation times from the location of WIND/Geotail to the location of Cluster were small. The propagation speeds of the SIs between the Cluster spacecraft were comparable to the solar wind speed. Our results suggest that the observed tail lobe SIs are due to lateral increases in solar wind dynamic pressure outside the magnetotail boundary.


2009 ◽  
Vol 27 (6) ◽  
pp. 2457-2474 ◽  
Author(s):  
C. Forsyth ◽  
M. Lester ◽  
R. C. Fear ◽  
E. Lucek ◽  
I. Dandouras ◽  
...  

Abstract. Following a solar wind pressure pulse on 3 August 2001, GOES 8, GOES 10, Cluster and Polar observed dipolarizations of the magnetic field, accompanied by an eastward expansion of the aurora observed by IMAGE, indicating the occurrence of two substorms. Prior to the first substorm, the motion of the plasma sheet with respect to Cluster was in the ZGSM direction. Observations following the substorms show the occurrence of current sheet waves moving predominantly in the −YGSM direction. Following the second substorm, the current sheet waves caused multiple current sheet crossings of the Cluster spacecraft, previously studied by Zhang et al. (2002). We further this study to show that the velocity of the current sheet waves was similar to the expansion velocity of the substorm aurora and the expansion of the dipolarization regions in the magnetotail. Furthermore, we compare these results with the current sheet wave models of Golovchanskaya and Maltsev (2005) and Erkaev et al. (2008). We find that the Erkaev et al. (2008) model gives the best fit to the observations.


Author(s):  
Timur Sh. KOMBAEV ◽  
Mikhail K. ARTEMOV ◽  
Valentin K. SYSOEV ◽  
Dmitry S. DEZHIN

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.


2021 ◽  
Author(s):  
Harlan Spence ◽  
Kristopher Klein ◽  
HelioSwarm Science Team

<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>


2018 ◽  
Vol 145 ◽  
pp. 03003
Author(s):  
Polya Dobreva ◽  
Monio Kartalev ◽  
Olga Nitcheva ◽  
Natalia Borodkova ◽  
Georgy Zastenker

We investigate the behaviour of the plasma parameters in the magnetosheath in a case when Interball-1 satellite stayed in the magnetosheath, crossing the tail magnetopause. In our analysis we apply the numerical magnetosheath-magnetosphere model as a theoretical tool. The bow shock and the magnetopause are self-consistently determined in the process of the solution. The flow in the magnetosheath is governed by the Euler equations of compressible ideal gas. The magnetic field in the magnetosphere is calculated by a variant of the Tsyganenko model, modified to account for an asymmetric magnetopause. Also, the magnetopause currents in Tsyganenko model are replaced by numericaly calulated ones. Measurements from WIND spacecraft are used as a solar wind monitor. The results demonstrate a good agreement between the model-calculated and measured values of the parameters under investigation.


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