Extended MHD modeling of the steady solar corona and the solar wind

Gombosi, T. I.; Holst, Bart van der; Manchester, W.; Соколов, И. В.

doi:10.1007/s41116-018-0014-4

Cited by 91 publications

(60 citation statements)

References 196 publications

(541 reference statements)

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“…The large-scale features of the solar wind flow are widely regarded as well-represented in a fluid (MHD) description (Tu & Marsch 1995;Goldstein et al 1995;Bruno & Carbone 2013;Matthaeus et al 2015;Makwana et al 2015;Parashar et al 2015). 5 The MHD description is particularly indispensable for global simulation of the solar wind (e.g., Gombosi et al 2018), where the largest length scales in the system span at least a few solar radii (1 R = 6.9×10 5 km). Kinetic effects come into play at the ion-inertial scale, which is roughly 90 km at 1 au (e.g., Schekochihin et al 2009) and becomes smaller closer to the sun.…”

Section: Solar Wind Modelmentioning

confidence: 99%

Contextual Predictions for the Parker Solar Probe. I. Critical Surfaces and Regions

Chhiber

Usmanov

Matthaeus

et al. 2019

ApJS

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The solar corona and young solar wind may be characterized by critical surfaces -the sonic, Alfvén, and first plasma-β unity surfaces -that demarcate regions where the solar wind flow undergoes certain crucial transformations. Global numerical simulations and remote sensing observations offer a natural mode for the study of these surfaces at large scales, thus providing valuable context for the highresolution in-situ measurements expected from the recently launched Parker Solar Probe (PSP ). The present study utilizes global three-dimensional magnetohydrodynamic (MHD) simulations of the solar wind to characterize the critical surfaces and investigate the flow in propinquitous regions. Effects of solar activity are incorporated by varying source magnetic dipole tilts and employing magnetogrambased boundary conditions. An MHD turbulence model is self-consistently coupled to the bulk-flow equations, enabling investigation of turbulence properties of the flow in the vicinity of critical regions. The simulation results are compared with a variety of remote sensing observations. A simulated PSP trajectory is used to provide contextual predictions for the spacecraft in terms of the computed critical surfaces. Broad agreement is seen in the interpretation of the present results in comparison with existing remote sensing results, both from heliospheric imaging and from radio scintillation studies. The trajectory analyses show that the period of time that PSP is likely to spend inside the β = 1, sonic, and Alfvén surfaces depends sensitively on the degree of solar activity and the tilt of the solar dipole and location of the heliospheric current sheet.

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Section: Solar Wind Modelmentioning

confidence: 99%

Contextual Predictions for the Parker Solar Probe. I. Critical Surfaces and Regions

Chhiber

Usmanov

Matthaeus

et al. 2019

ApJS

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“…We proceed in a similar manner to Alvarado-Gómez et al (2018), first obtaining a steady-state description of the corona and stellar wind, and then using this solution as an initial condition of a time-dependent fluxrope CME simulation. The models employed here are incorporated in the latest version of the Space Weather Modeling Framework (SWMF, see Gombosi et al 2018).…”

Section: Numerical Modelsmentioning

confidence: 99%

Coronal Response to Magnetically Suppressed CME Events in M-dwarf Stars

Alvarado‐Gómez

Drake

Moschou

et al. 2019

ApJL

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We report the results of the first state-of-the-art numerical simulations of Coronal Mass Ejections (CMEs) taking place in realistic magnetic field configurations of moderately active M-dwarf stars. Our analysis indicates that a clear, novel, and observable, coronal response is generated due to the collapse of the eruption and its eventual release into the stellar wind. Escaping CME events, weakly suppressed by the large-scale field, induce a flare-like signature in the emission from coronal material at different temperatures due to compression and associated heating. Such flare-like profiles display a distinctive temporal evolution in their Doppler shift signal (from red to blue), as the eruption first collapses towards the star and then perturbs the ambient magnetized plasma on its way outwards. For stellar fields providing partial confinement, CME fragmentation takes place, leading to rise and fall flow patterns which resemble the solar coronal rain cycle. In strongly suppressed events, the response is better described as a gradual brightening, in which the failed CME is deposited in the form of a coronal rain cloud leading to a much slower rise in the ambient high-energy flux by relatively small factors (∼ 2 − 3). In all the considered cases (escaping/confined) a fractional decrease in the emission from mid-range coronal temperature plasma occurs, similar to the coronal dimming events observed on the Sun. Detection of the observational signatures of these CME-induced features requires a sensitive next generation X-ray space telescope.

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“…Three-dimensional (3D) magnetohydrodynamics (MHD) ambient solar wind models are critical tools for space weather forecasting (Feng et al, 2011a(Feng et al, , 2013Wu & Dryer, 2015;Gombosi et al, 2018;Feng, 2020). The first 3D MHD solar wind model transitioned into operations is the Wang-Sheeley-Arge-ENLIL (WSA-ENLIL) model (Odstrcil, 2003), which is responsible for providing 1-4 day solar wind condition forecasts upstream of the Earth, and has been updated to its 2.0 version recently (Note that version number 2.0 of the WSA-ENLIL model is different from the individual version numbers of WSA and ENLIL models).…”

Section: Introductionmentioning

confidence: 99%

Assessment of CESE-HLLD ambient solar wind model results using multipoint observation

Feng

Wei

2020

J. Space Weather Space Clim.

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For a three-dimensional magnetohydrodynamics solar wind model, it is necessary to carry out assessment studies to reveal its ability and limitation. In this paper, the ambient solar wind results of year 2008 generated by the CESE-HLLD 3D MHD model are compared with multipoint in-situ measurements during the late declining phase of solar cycle 23. The near-ecliptic results are assessed both quantitatively and qualitatively by comparing with in-situ data obtained at the L1 point and by the twin STEREO spacecraft. The assessment reveals the model's ability in reproducing the time series and statistical characteristics of solar wind parameters, and in catching the change of interplanetary magnetic field polarity and the occurrence of the stream interaction regions. We find that the two-stream structure observed near the ecliptic plane is reproduced, but the differences among observations at L1 and the twin STEREO spacecraft are not caught by the model. The latitudinal variation of the results is assessed by comparing with the Ulysses observation. The characters of variation in different latitudinal ranges are duplicated by the model, but biases of the results are seen, and the boundary layers between fast and slow solar wind are sometimes thicker than observation.

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Extended MHD modeling of the steady solar corona and the solar wind

Cited by 91 publications

References 196 publications

Contextual Predictions for the Parker Solar Probe. I. Critical Surfaces and Regions

Contextual Predictions for the Parker Solar Probe. I. Critical Surfaces and Regions

Coronal Response to Magnetically Suppressed CME Events in M-dwarf Stars

Assessment of CESE-HLLD ambient solar wind model results using multipoint observation

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