Tsallis distributions of the large-scale magnetic field strength fluctuations in the solar wind from 7 to 87 AU

Marchwinski et al. (2012) mapped the magnetic field strength across the quiescent cloud GRSMC 45.60+0.30 (shown in Figure 1 subtending 40x10 pc at a distance of 1.88 kpc) with the Chandrasekhar-Fermi method CF; Chandrasekhar & Fermi 1953) using near-infrared starlight polarimetry from the Galactic Plane Infrared Polarization Survey (Clemens et al.2012a, b) and gas properties from the Galactic Ring Survey (Jackson et al.2006). The large-scale magnetic field is oriented parallel to the gas-traced ‘spine’ of the cloud. Seven ‘magnetic cores’ with high magnetic field strength were identified and are coincident with peaks in the gas column density. Calculation of the mass-to-flux ratio (Crutcher 1999) shows that these cores are exclusively magnetically subcritical and that magnetostatic pressure can support them against gravitational collapse.

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SECTORS AND LARGE-SCALE MAGNETIC FIELD STRENGTH FLUCTUATIONS IN THE HELIOSHEATH NEAR 110 AU:VOYAGER 1, 2009

The Astrophysical Journal ◽

10.1088/0004-637x/725/1/1306 ◽

2010 ◽

Vol 725 (1) ◽

pp. 1306-1316 ◽

Cited By ~ 34

Author(s):

L. F. Burlaga ◽

N. F. Ness

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Large Scale ◽

Large Scale Magnetic Field

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The magnetic field of the evolved star W43A

Proceedings of the International Astronomical Union ◽

10.1017/s174392130903021x ◽

2008 ◽

Vol 4 (S259) ◽

pp. 109-110

Author(s):

Nikta Amiri ◽

Wouter Vlemmings ◽

Huib Jan van Langevelde

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Circular Polarization ◽

Magnetic Field Strength ◽

Large Scale ◽

Zeeman Splitting ◽

Density Region ◽

Evolved Stars ◽

Large Scale Magnetic Field ◽

The Magnetic Field

AbstractPlanetary nebulae (PNe) often show large departures from spherical symmetry. The origin and development of these asymmetries is not clearly understood. The most striking structures are the highly collimated jets that are already observed in a number of evolved stars before they enter the PN phase. The aim of this project is to observe the Zeeman splitting of the OH maser of the W43A star and determine the magnetic field strength in the low density region. The 1612 MHz OH masers of W43A were observed with MERLIN to measure the circular polarization due to the Zeeman splitting of 1612 OH masers in the envelope of the evolved star W43A. We measured the circular polarization of the strongest 1612 OH masers of W43A and found a magnetic field strength of ~100μG. The magnetic field measured at the location of W43A OH masers confirms that a large scale magnetic field is present in W43A, which likely plays a role in collimating the jet.

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An Asymptotic Investigation of the Non-stationary Modes of Instability on a Rotating-disk in the Presence of a Large Magnetic Field Strength

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v34i1.5491 ◽

1970 ◽

Vol 34 (1) ◽

pp. 49-58

Author(s):

HA Jasmine

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Field Strength ◽

Magnetic Field Strength ◽

Large Scale ◽

Rotating Disk ◽

Lower Branch ◽

Large Scale Magnetic Field ◽

Asymptotic Investigation ◽

Academy Of Sciences

Asymptotic solutions for stationary and non-stationary modes for the upper and lower branchdisturbances assuming large scale magnetic fields are investigated. A triple deck structure whichgoverns the lower branch modes for a large scale magnetic field is displayed. The wavenumbersand waveangle calculated from the eigenrelations α ≈ 2.62m5/4r-1/2, β ≈ 0.78 m1/4 r1/2, φ = 0.298m-1r, to be consistent with the numerical results for large scale magnetic fields.Key words: Magnetic field; Instability; Rotating-disk flowDOI: 10.3329/jbas.v34i1.5491Journal of Bangladesh Academy of Sciences, Vol.34, No.1, 49-58, 2010

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Multifractal structure of the large-scale heliospheric magnetic field strength fluctuations near 85AU

Nonlinear Processes in Geophysics ◽

10.5194/npg-11-441-2004 ◽

2004 ◽

Vol 11 (4) ◽

pp. 441-445 ◽

Cited By ~ 13

Author(s):

L. F. Burlaga

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Large Scale ◽

Solar Maximum ◽

Multifractal Spectrum ◽

The Sun ◽

Heliographic Latitude ◽

The Mean ◽

The Magnetic Field

Abstract. During 2002, the Voyager 1 spacecraft was in the heliosphere between 83.4 and 85.9AU (1AU is the mean distance from the Sun to Earth) at 34° N heliographic latitude. The magnetic field strength profile observed in this region had a multifractal structure in the range of scales from 2 to 16 days. The multifractal spectrum observed near 85AU is similar to that observed near 40AU, indicating relatively little evolution of the multifractal structure of the magnetic field with increasing distance in the distant heliosphere in the epoch near solar maximum.

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Radial dependence of foreshock cavities: a case study

Annales Geophysicae ◽

10.5194/angeo-22-4143-2004 ◽

2004 ◽

Vol 22 (12) ◽

pp. 4143-4151 ◽

Cited By ~ 6

Author(s):

D. G. Sibeck ◽

K. Kudela ◽

T. Mukai ◽

Z. Nemecek ◽

J. Safrankova

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Field Strength ◽

Magnetic Field Strength ◽

Bow Shock ◽

Radial Dependence ◽

Energetic Ions ◽

Interplanetary Physics ◽

Bow Shocks

Abstract. We present a case study of Geotail, Interball-1, IMP-8, and Wind observations of density and magnetic field strength cavities excavated by the enhanced pressures associated with bursts of energetic ions in the foreshock. Consistent with theoretical predictions, the pressure of the energetic ions diminishes rapidly with upstream distance due to a decrease in the flux of energetic ions and a transition from near-isotropic to streaming pitch angle distributions. Consequently, the cavities can only be observed immediately upstream from the bow shock. A comparison of conditions upstream from the pre- and post-noon bow shock demonstrates that foreshock cavities introduce perturbations into the oncoming solar wind flow with dimensions smaller than those of the magnetosphere. Dayside geosynchronous magnetic field strength variations observed by GOES-8 do not track the density variations seen by any of the spacecraft upstream from the bow shock in a one-to-one manner, indicating that none of these spacecraft observed the precise sequence of density variations that actually struck the subsolar magnetopause. Key words. Interplanetary physics (energetic particles; planetary bow shocks) – Magnetospheric physics (solar wind-magnetosphere interactions)

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Resistive evolution of toroidal field distributions and their relation to magnetic clouds

Journal of Plasma Physics ◽

10.1017/s0022377818001290 ◽

2019 ◽

Vol 85 (1) ◽

Author(s):

C. B. Smiet ◽

H. J. de Blank ◽

T. A. de Jong ◽

D. N. L. Kok ◽

D. Bouwmeester

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Field Strength ◽

Magnetic Field Strength ◽

Magnetic Clouds ◽

Twisted Field ◽

Field Lines ◽

Rotational Transform ◽

Universal Pattern ◽

The Magnetic Field

We study the resistive evolution of a localized self-organizing magnetohydrodynamic equilibrium. In this configuration the magnetic forces are balanced by a pressure force caused by a toroidal depression in the pressure. Equilibrium is attained when this low-pressure region prevents further expansion into the higher-pressure external plasma. We find that, for the parameters investigated, the resistive evolution of the structures follows a universal pattern when rescaled to resistive time. The finite resistivity causes both a decrease in the magnetic field strength and a finite slip of the plasma fluid against the static equilibrium. This slip is caused by a Pfirsch–Schlüter-type diffusion, similar to what is seen in tokamak equilibria. The net effect is that the configuration remains in magnetostatic equilibrium whilst it slowly grows in size. The rotational transform of the structure becomes nearly constant throughout the entire structure, and decreases according to a power law. In simulations this equilibrium is observed when highly tangled field lines relax in a high-pressure (relative to the magnetic field strength) environment, a situation that occurs when the twisted field of a coronal loop is ejected into the interplanetary solar wind. In this paper we relate this localized magnetohydrodynamic equilibrium to magnetic clouds in the solar wind.

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Cassini observations of magnetic holes in the solar wind and Saturn magnetosheath

10.5194/egusphere-egu2020-100 ◽

2020 ◽

Author(s):

Tomas Karlsson ◽

Lina Hadid ◽

Michiko Morooka ◽

Jan-Erik Wahlund

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Field Strength ◽

Magnetic Field Strength ◽

High Time Resolution ◽

Magnetic Field Direction ◽

Scale Size ◽

Background Magnetic Field ◽

Cycle Dependence ◽

The Magnetic Field

We present the first Cassini observations of magnetic holes on the near-Saturn solar wind and magnetosheath, based on data from the MAG magnetometer. We conclude that magnetic holes (defined as isolated decreases of at least 50% compared to the background magnetic field strength) are common in both regions. We present statistical properties of the magnetic holes, including scale size, depth of the magnetic field reduction, orientation, change in magnetic field direction over the holes, and solar cycle dependence. For magnetosheath magnetic holes, also high-time resolution density measurements from the LP Langmuir probe are available, allowing us to study the anti-correlation of density and magnetic field strength in the magnetic holes. We compare to recent results from MESSENGER observations from Mercury orbit, and finally discuss the possible importance of magnetic holes in solar wind-magnetosphere interaction at Saturn.

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Simultaneous longitudinal and transverse oscillations in filament threads after a failed eruption

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936453 ◽

2019 ◽

Vol 633 ◽

pp. A12 ◽

Cited By ~ 3

Author(s):

Rakesh Mazumder ◽

Vaibhav Pant ◽

Manuel Luna ◽

Dipankar Banerjee

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Large Amplitude ◽

Large Scale ◽

Radius Of Curvature ◽

Solar Dynamics Observatory ◽

Solar Prominences ◽

Solar Dynamics ◽

Transverse Oscillations

Context. Longitudinal and transverse oscillations are frequently observed in the solar prominences and/or filaments. These oscillations are excited by a large-scale shock wave, impulsive flares at one leg of the filament threads, or due to any low coronal eruptions. We report simultaneous longitudinal and transverse oscillations in the filament threads of a quiescent region filament. We observe a large filament in the northwest of the solar disk on July 6, 2017. On July 7, 2017, it starts rising around 13:00 UT. We then observe a failed eruption and subsequently the filament threads start to oscillate around 16:00 UT. Aims. We analyse oscillations in the threads of a filament and utilize seismology techniques to estimate magnetic field strength and length of filament threads. Methods. We placed horizontal and vertical artificial slits on the filament threads to capture the longitudinal and transverse oscillations of the threads. Data from Atmospheric Imaging Assembly onboard Solar Dynamics Observatory were used to detect the oscillations. Results. We find signatures of large-amplitude longitudinal oscillations (LALOs). We also detect damping in LALOs. In one thread of the filament, we observe large-amplitude transverse oscillations (LATOs). Using the pendulum model, we estimate the lower limit of magnetic field strength and radius of curvature from the observed parameter of LALOs. Conclusions. We show the co-existence of two different wave modes in the same filament threads. We estimate magnetic field from LALOs and suggest a possible range of the length of the filament threads using LATOs.

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Predicting geo-effectiveness of CMEs using a novel 3D CME model FRi3D integrated into EUHFORIA

10.5194/egusphere-egu21-11605 ◽

2021 ◽

Author(s):

Stefaan Poedts ◽

Anwesha Maharana ◽

Camilla Scolini ◽

Alexey Isavnin

Keyword(s):

Magnetic Field ◽

Solar Wind ◽

Field Strength ◽

Magnetic Field Strength ◽

Three Dimensional ◽

Flux Rope ◽

Future Perspective ◽

The European Union ◽

Horizon 2020 ◽

The Magnetic Field

Previous studies of Coronal Mass Ejections (CMEs) have shown the importance of understanding their geometrical structure and internal magnetic field configuration for improving forecasting at Earth. The precise prediction of the CME shock and the magnetic cloud arrival time, their magnetic field strength and the orientation upon impact at Earth is still challenging and relies on solar wind and CME evolution models and precise input parameters. In order to understand the propagation of CMEs in the interplanetary medium, we need to understand their interaction with the complex features in the magnetized background solar wind which deforms, deflects and erodes the CMEs and determines their geo-effectiveness. Hence, it is important to model the internal magnetic flux-rope structure in the CMEs as they interact with CIRs/SIRs, other CMEs and solar transients in the heliosphere. The spheromak model (Verbeke et al. 2019) in the heliospheric wind and CME evolution simulation EUHFORIA (Pomoell and Poedts, 2018), fits well with the data near the CME nose close to its axis but fails to predict the magnetic field in CME legs when these impact Earth (Scolini et al. 2019). Therefore, we implemented the FRi3D stretched flux-rope CME model (Isavnin, 2016) in EUHFORIA to model a more realistic CME geometry. Fri3D captures the three-dimensional magnetic field structure with parameters like skewing, pancaking and flattening that quantify deformations experienced by an interplanetary CME. We perform test runs of real CME events and validate the ability of FRi3D coupled with EUHFORIA in predicting the CME geo-effectiveness. We have modeled two real events with FRi3D. First, a CME event on 12 July 2012 which was a head-on encounter at Earth. Second, the flank CME encounter of 14 June 2012 which did not leave any magnetic field signature at Earth when modeled with Spheromak. We compare our results with the results from non-magnetized cone simulations and magnetized simulations employing the spheromak flux-rope model. We further discuss how constraining observational parameters using the stretched flux rope CME geometry in FRi3D affects the prediction of the magnetic field strength in our simulations, highlighting improvements and discussing future perspective.This research has received funding from the European Union&#8217;s Horizon 2020 research and innovation programme under grant agreement No 870405 (EUHFORIA 2.0)

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