Ultrahigh-resolution model of a breakout CME embedded in the solar wind

Hosteaux, Skralan; Chané, Emmanuel; Decraemer, Bieke; Talpeanu, Dana-Camelia; Poedts, Stefaan

doi:10.1051/0004-6361/201832976

Cited by 28 publications

(15 citation statements)

References 27 publications

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“…To resolve these tearing instabilities and their resulting magnetic islands in numerical simulations, a high resolution at the current sheets is necessary. Recent progress in this area has been made by Karpen et al (2012), Guidoni et al (2016) and Hosteaux et al (2018). They are not present at the front of an inverse CME, but at the rear because this is where a current sheet forms when the CME has the same polarity as the solar wind.…”

Section: Synthetic Satellite At L1mentioning

confidence: 99%

Effect of the solar wind density on the evolution of normal and inverse coronal mass ejections

Hosteaux

Chané

Poedts

2019

A&A

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Context. The evolution of magnetised coronal mass ejections (CMEs) and their interaction with the background solar wind leading to deflection, deformation, and erosion is still largely unclear as there is very little observational data available. Even so, this evolution is very important for the geo-effectiveness of CMEs. Aims. We investigate the evolution of both normal and inverse CMEs ejected at different initial velocities, and observe the effect of the background wind density and their magnetic polarity on their evolution up to 1 AU. Methods. We performed 2.5D (axisymmetric) simulations by solving the magnetohydrodynamic (MHD) equations on a radially stretched grid, employing a block-based adaptive mesh refinement (AMR) scheme based on a density threshold to achieve high resolution following the evolution of the magnetic clouds and the leading bow shocks. All the simulations discussed in the present paper were performed using the same initial grid and numerical methods.Results. The polarity of the internal magnetic field of the CME has a substantial effect on its propagation velocity and on its deformation and erosion during its evolution towards Earth. We quantified the effects of the polarity of the internal magnetic field of the CMEs and of the density of the background solar wind on the arrival times of the shock front and the magnetic cloud. We determined the positions and propagation velocities of the magnetic clouds and thus also the stand-off distance of the leading shock fronts (i.e. the thickness of the magnetic sheath region) and the deformation and erosion of the magnetic clouds during their evolution from the Sun to the Earth. Inverse CMEs were found to be faster than normal CMEs ejected in the same initial conditions, but with smaller stand-off distances. They also have a higher magnetic cloud length, opening angle, and mass. Synthetic satellite time series showed that the shock magnitude is not affected by the polarity of the CME. However, the density peak of the magnetic cloud is dependent on the polarity and, in case of inverse CMEs, also on the background wind density. The magnitude of the z-component of the magnetic field was not influenced by either the polarity or the wind density.

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Section: Synthetic Satellite At L1mentioning

confidence: 99%

Effect of the solar wind density on the evolution of normal and inverse coronal mass ejections

Hosteaux

Chané

Poedts

2019

A&A

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“…The grid was refined to a maximum of two additional levels and only in the regions of interest, where the electrical current presented an enhancement, that is at potential magnetic reconnection sites. This increase is quantified through a parameter taken from Karpen et al (2012) and also used by Hosteaux et al (2018) as follows:…”

Section: Simulations Set-up and Methodsmentioning

confidence: 99%

Numerical simulations of shear-induced consecutive coronal mass ejections

Talpeanu

Chané

Poedts

et al. 2020

A&A

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Context. It is widely accepted that photospheric shearing motions play an important role in triggering the initiation of coronal mass ejections (CMEs). Even so, there are events for which the source signatures are difficult to locate, while the CMEs can be clearly observed in coronagraph data. These events are therefore called 'stealth' CMEs. They are of particular interest to space weather forecasters, since eruptions are usually discarded from arrival predictions if they appear to be backsided, which means not presenting any clear low-coronal signatures on the visible solar disc. Such assumptions are not valid for stealth CMEs since they can originate from the front side of the Sun and be Earth-directed, but they remain undetected and can therefore trigger unpredicted geomagnetic storms. Aims. We numerically model and investigate the effects of shearing motion variations onto the resulting eruptions and we focus in particular on obtaining a stealth CME in the trailing current sheet of a previous ejection. Methods. We used the 2.5D magnetohydrodynamics package of the code MPI-AMRVAC to numerically simulate consecutive CMEs by imposing shearing motions onto the inner boundary, which represents, in our case, the low corona. The initial magnetic configuration consists of a triple arcade structure embedded into a bimodal solar wind, and the sheared polarity inversion line is found in the southern loop system. The mesh was continuously adapted through a refinement method that applies to current carrying structures, allowing us to easily track the CMEs in high resolution, without resolving the grid in the entire domain. We also compared the obtained eruptions with the observed directions of propagation, determined using a forward modelling reconstruction technique based on a graduated cylindrical shell geometry, of an initial multiple coronal mass ejection (MCME) event that occurred in September 2009. We further analysed the simulated ejections by tracking the centre of their flux ropes in latitude and their total speed. Radial Poynting flux computation was employed as well to follow the evolution of electromagnetic energy introduced into the system. Results. Changes within 1% in the shearing speed result in three different scenarios for the second CME, although the preceding eruption seems insusceptible to such small variations. Depending on the applied shearing speed, we thus obtain a failed eruption, a stealth, or a CME driven by the imposed shear, as the second ejection. The dynamics of all eruptions are compared with the observed directions of propagation of an MCME event and a good correlation is achieved. The Poynting flux analysis reveals the temporal variation of the important steps of eruptions. Conclusions. For the first time, a stealth CME is simulated in the aftermath of a first eruption, originating from an asymmetric streamer configuration, through changes in the applied shearing speed, indicating it is not necessary for a closed streamer to exist high in the corona for such an event to occur. We also e...

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“…Pei et al, 2006), and smaller scale structures may also play a role in the evolution of CMEs (see e.g. Hosteaux et al, 2018), topics which are far from being fully understood.…”

Section: Agation Of Various Solar Disturbances (Coronal Mass Ejectionmentioning

confidence: 99%

Reconstruction of the Parker spiral with the Reverse In situ data and MHD APproach – RIMAP

Biondo

Бемпорад

Mignone

et al. 2021

J. Space Weather Space Clim.

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The reconstruction of plasma parameters in the interplanetary medium is very important to understand the interplanetary propagation of solar eruptions and for Space Weather application purposes. Because only a few spacecraft are measuring in situ these parameters, reconstructions are currently performed by running complex numerical Magneto-hydrodynamic (MHD) simulations starting from remote sensing observations of the Sun. Current models apply full 3D MHD simulations of the corona or extrapolations of photospheric magnetic fields combined with and semiempirical relationships to derive the plasma parameters on a sphere centered on the Sun (inner boundary). The plasma is then propagated in the interplanetary medium up to the Earth’s orbit and beyond. Nevertheless, this approach requires significant theoretical and computational efforts, and the results are only in partial agreement with the in situ observations. In this paper we describe a new approach to this problem called RIMAP - Reverse In situ data and MHD APproach. The plasma parameters in the inner boundary at 0.1 AU are derived directly from the in situ measurements acquired at 1 AU, by applying a back reconstruction technique to remap them into the inner heliosphere. This remapping is done by using the Weber and Davies solar wind theoretical model to reconstruct the wind flowlines. The plasma is then re-propagated outward from 0.1 AU by running a MHD numerical simulation based on the PLUTO code. The interplanetary spiral reconstructions obtained with RIMAP are not only in a much better agreement with the in situ observations, but are also including many more small-scale longitudinal features in the plasma parameters that are not reproduced with the approaches developed so far.

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Ultrahigh-resolution model of a breakout CME embedded in the solar wind

Cited by 28 publications

References 27 publications

Effect of the solar wind density on the evolution of normal and inverse coronal mass ejections

Effect of the solar wind density on the evolution of normal and inverse coronal mass ejections

Numerical simulations of shear-induced consecutive coronal mass ejections

Reconstruction of the Parker spiral with the Reverse In situ data and MHD APproach – RIMAP

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