Sun-to-Earth MHD Simulation of the 2000 July 14 “Bastille Day” Eruption

Török, Tibor; Downs, Cooper; Linker, J. A.; Lionello, R.; Titov, V. S.; Mikić, Z.; Riley, Pete; Caplan, Ronald M.; Wijaya, Janvier

doi:10.3847/1538-4357/aab36d

Cited by 159 publications

(131 citation statements)

References 191 publications

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“…Especially looking at different spacecraft locations, we found that the magnetic cloud structure that is arriving at 1 au is sensitive to a change of only a few degrees. A similar conclusion has recently been highlighted by Török et al (2018). Keeping in mind that the error in kinematic CME parameters obtained from observations, such as latitude and longitude, can have errors larger than the discussed shift from Earth to the virtual spacecraft, it is needed to proceed with care when performing only one run with the LFFS model.…”

Section: Discussion and Summarysupporting

confidence: 56%

The evolution of coronal mass ejections in the inner heliosphere: Implementing the spheromak model with EUHFORIA

Verbeke

Pomoell

Poedts

2019

A&A

107

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Aims.We introduce a new model for coronal mass ejections (CMEs) that has been implemented in the magnetohydrodynamics (MHD) inner heliosphere model EUHFORIA. Utilising a linear force-free spheromak (LFFS) solution, the model provides an intrinsic magnetic field structure for the CME. As a result, the new model has the potential to predict the magnetic components of CMEs at Earth. In this paper, we present the implementation of the new model and show the capability of the new model. Methods. We present initial validation runs for the new magnetised CME model by considering the same set of events as used in the initial validation run of EUHFORIA that employed the Cone model. In particular, we have focused on modelling the CME that was responsible for creating the largest geomagnetic disturbance (Dst index). Two scenarios are discussed: one where a single magnetised CME is launched and another in which we launch all five Earth-directed CMEs that were observed during the considered time period. Four out of the five CMEs were modelled using the Cone model. Results. In the first run, where the propagation of a single magnetized CME is considered, we find that the magnetic field components at Earth are well reproduced as compared to in-situ spacecraft data. Considering a virtual spacecraft that is separated approximately seven heliographic degrees from the position of Earth, we note that the centre of the magnetic cloud is missing Earth and a considerably larger magnetic field strength can be found when shifting to that location. For the second run, launching four Cone CMEs and one LFFS CME, we notice that the simulated magnetised CME is arriving at the same time as in the corresponding full Cone model run. We find that to achieve this, the speed of the CME needs to be reduced in order to compensate for the expansion of the CME due to the addition of the magnetic field inside the CME. The reduced initial speed of the CME and the added magnetic field structure give rise to a very similar propagation of the CME with approximately the same arrival time at 1 au. In contrast to the Cone model, however, the magnetised CME is able to predict the magnetic field components at Earth. However, due to the interaction between the Cone model CMEs and the magnetised CME, the magnetic field amplitude is significantly lower than for the run using a single magnetised CME. Conclusions. We have presented the LFFS model that is able to simulate and predict the magnetic field components and the propagation of magnetised CMEs in the inner heliosphere and at Earth. We note that shifting towards a virtual spacecraft in the neighbourhood of Earth can give rise to much stronger magnetic field components. This gives the option of adding a grid of virtual spacecrafts to give a range of values for the magnetic field components.

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Section: Discussion and Summarysupporting

confidence: 56%

The evolution of coronal mass ejections in the inner heliosphere: Implementing the spheromak model with EUHFORIA

Verbeke

Pomoell

Poedts

2019

A&A

107

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“…It should be noted, however, that MHD simulations are capable of incorporating the internal CME magnetic field (e.g. Torok et al, 2018), although it is difficult to implement in a forecasting situation and is not currently used operationally. The effect of non-hydrodynamic effects on CME arrival times has yet to be quantified, although it is expected to be relatively small.…”

Section: Discussionmentioning

confidence: 99%

A Computationally Efficient, Time-Dependent Model of the Solar Wind for Use as a Surrogate to Three-Dimensional Numerical Magnetohydrodynamic Simulations

et al. 2020

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Near-Earth solar-wind conditions, including disturbances generated by coronal mass ejections (CMEs), are routinely forecast using three-dimensional, numerical magnetohydrodynamic (MHD) models of the heliosphere. The resulting forecast errors are largely the result of uncertainty in the near-Sun boundary conditions, rather than heliospheric model physics or numerics. Thus ensembles of heliospheric model runs with perturbed initial conditions are used to estimate forecast uncertainty. MHD heliospheric models are relatively cheap in computational terms, requiring tens of minutes to an hour to simulate CME propagation from the Sun to Earth. Thus such ensembles can be run operationally. However, ensemble size is typically limited to 10 1 to 10 2 members, which may be inadequate to sample the relevant high-dimensional parameter space. Here, we describe a simplified solarwind model that can estimate CME arrival time in approximately 0.01 seconds on a modest desktop computer and thus enables significantly larger ensembles. It is a one-dimensional, incompressible, hydrodynamic model, which has previously been used for the steady-state solar wind, but it is here used in time-dependent form. This approach is shown to adequately emulate the MHD solutions to the same boundary conditions for both steady-state solar wind and CME-like disturbances. We suggest it could serve as a "surrogate" model for the full three-dimensional MHD models. For example, ensembles of 10 5 to 10 6 members can be used to identify regions of parameter space for more detailed investigation by the MHD models. Similarly, the simplicity of the model means it can be rewritten as an adjoint model, enabling variational data assimilation with MHD models without the need to alter their code. The model code is available as an Open Source download in the Python language. B M. Owens 5 Met Office, Exeter, UK 43 Page 2 of 17 M. Owens et al.Figure 1 An example of a three-dimensional numerical MHD solution of the solar wind, using the MAS coronal model and the HelioMAS heliospheric model. The photospheric magnetic field for Carrington Rotation 1833 (spanning September 1990) was used, as it results in both fast and slow wind in the equatorial plane. (a) Latitude-time plot at Earth longitude of V r at the corona-heliosphere interface (30 R ) from MAS. (Note if the solar-wind structure is time stationary, this is an exact mirror image of a Carrington map.) The white line shows the Heliographic Equator. (b) The associated time series of V r at the sub-Earth point. (c) Latitude-time plot at Earth longitude of V r at Earth orbit (215 R ) from HelioMAS. (d) The associated time series of V r at Earth from HelioMAS (black) and HUXt (red). See text for details of the HelioMAS and HUXt models.Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a lin...

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“…While a polytropic stellar wind outflow naturally creates a significant mass density gradient between the openflux regions (coronal holes) and the closed-field corona (the helmet streamer belt), a more realistic treatment of the internal energy equation is expected to increase this density contrast for both the quiet-Sun and active regions (e.g. Török et al 2018). The isothermal model for our stellar atmosphere has two main consequences for our simulation results: first, on the structure and intensities associated with our synthetic EUV and soft X-ray emission profiles; second, on the interaction between the CME and the background wind, including the properties of the CME-driven shock.…”

Section: Discussionmentioning

confidence: 99%

Modeling a Carrington-scale Stellar Superflare and Coronal Mass Ejection from

Lynch

Airapetian

DeVore

et al. 2019

ApJ

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Observations from the Kepler mission have revealed frequent superflares on young and active solarlike stars. Superflares result from the large-scale restructuring of stellar magnetic fields, and are associated with the eruption of coronal material (a coronal mass ejection, or CME) and energy release that can be orders of magnitude greater than those observed in the largest solar flares. These catastrophic events, if frequent, can significantly impact the potential habitability of terrestrial exoplanets through atmospheric erosion or intense radiation exposure at the surface. We present results from numerical modeling designed to understand how an eruptive superflare from a young solar-type star, κ 1 Cet, could occur and would impact its astrospheric environment. Our data-inspired, three-dimensional magnetohydrodynamic modeling shows that global-scale shear concentrated near the radial-field polarity inversion line can energize the closed-field stellar corona sufficiently to power a global, eruptive superflare that releases approximately the same energy as the extreme 1859 Carrington event from the Sun. We examine proxy measures of synthetic emission during the flare and estimate the observational signatures of our CME-driven shock, both of which could have extreme space-weather impacts on the habitability of any Earth-like exoplanets. We also speculate that the observed 1986 Robinson-Bopp superflare from κ 1 Cet was perhaps as extreme for that star as the Carrington flare was for the Sun.

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Sun-to-Earth MHD Simulation of the 2000 July 14 “Bastille Day” Eruption

Cited by 159 publications

References 191 publications

The evolution of coronal mass ejections in the inner heliosphere: Implementing the spheromak model with EUHFORIA

The evolution of coronal mass ejections in the inner heliosphere: Implementing the spheromak model with EUHFORIA

A Computationally Efficient, Time-Dependent Model of the Solar Wind for Use as a Surrogate to Three-Dimensional Numerical Magnetohydrodynamic Simulations

Modeling a Carrington-scale Stellar Superflare and Coronal Mass Ejection from

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