Abstract
Solar and stellar flares are the most intense emitters of X-rays and extreme ultraviolet radiation in planetary systems1,2. On the Sun, strong flares are usually found in newly emerging sunspot regions3. The emergence of these magnetic sunspot groups leads to the accumulation of magnetic energy in the corona. When the magnetic field undergoes abrupt relaxation, the energy released powers coronal mass ejections as well as heating plasma to temperatures beyond tens of millions of kelvins. While recent work has shed light on how magnetic energy and twist accumulate in the corona4 and on how three-dimensional magnetic reconnection allows for rapid energy release5,6, a self-consistent model capturing how such magnetic changes translate into observable diagnostics has remained elusive. Here, we present a comprehensive radiative magnetohydrodynamics simulation of a solar flare capturing the process from emergence to eruption. The simulation has sufficient realism for the synthesis of remote sensing measurements to compare with observations at visible, ultraviolet and X-ray wavelengths. This unifying model allows us to explain a number of well-known features of solar flares7, including the time profile of the X-ray flux during flares, origin and temporal evolution of chromospheric evaporation and condensation, and sweeping of flare ribbons in the lower atmosphere. Furthermore, the model reproduces the apparent non-thermal shape of coronal X-ray spectra, which is the result of the superposition of multi-component super-hot plasmas8 up to and beyond 100 million K.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
Solar X-ray and EUV imager on board the FY-3E satellite
Light: Science & Applications Open Access 22 November 2022
-
Magnetic imaging of the outer solar atmosphere (MImOSA)
Experimental Astronomy Open Access 03 August 2021
-
A New View of the Solar Interface Region from the Interface Region Imaging Spectrograph (IRIS)
Solar Physics Open Access 25 May 2021
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout



Data availability
We have opted not to make the MURaM code publicly available. The codebase is frequently updated, and running the code in an appropriate and efficient manner requires expert assistance. The numerical methods employed by the code are provided in detail in refs 17,50. Interested parties are invited to contact the authors for more detailed information. Simulation snapshots are available for download from the Stanford Digital Repository (https://purl.stanford.edu/dv883vb9686). The repository also provides Interactive Data Language and Python routines for analysing the simulation data.
References
Priest, E. R. & Forbes, T. G. The magnetic nature of solar flares. Astron. Astrophys. Rev. 10, 313–377 (2002).
Shibata, K. & Magara, T. Solar flares: magnetohydrodynamic processes. Living Rev. Solar Phys. 8, 6 (2011).
Schrijver, C. J. Driving major solar flares and eruptions: a review. Adv. Space Res. 43, 739–755 (2009).
Fisher, G. H. et al. The coronal global evolutionary model: using HMI vector magnetogram and Doppler data to model the buildup of free magnetic energy in the solar corona. Space Weather 13, 369–373 (2015).
Amari, T., Canou, A. & Aly, J.-J. Characterizing and predicting the magnetic environment leading to solar eruptions. Nature 514, 465–469 (2014).
Wyper, P. F., Antiochos, S. K. & DeVore, C. R. A universal model for solar eruptions. Nature 544, 452–455 (2017).
Benz, A. O. Flare observations. Living Rev. Solar Phys. 5, 1 (2008).
Caspi, A. & Lin, R. P. RHESSI line and continuum observations of super-hot flare plasma. Astrophys. J. Lett. 725, L161–L166 (2010).
Fisher, G. H., Canfield, R. C. & McClymont, A. N. Flare loop radiative hydrodynamics. VI. Chromospheric evaporation due to heating by nonthermal electrons. Astrophys. J. 289, 425–433 (1985).
Reeves, K. K., Warren, H. P. & Forbes, T. G. Theoretical predictions of X-ray and extreme-UV flare emissions using a loss-of-equilibrium model of solar eruptions. Astrophys. J. 668, 1210–1220 (2007).
Longcope, D. W., Guidoni, S. E. & Linton, M. G. Gas-dynamic shock heating of post-flare loops due to retraction following localized, impulsive reconnection. Astrophys. J. Lett. 690, L18–L22 (2009).
Takasao, S., Matsumoto, T., Nakamura, N. & Shibata, K. Magnetohydrodynamic shocks in and above post-flare loops: two-dimensional simulation and a simplified model. Astrophys. J. 805, 135 (2015).
Kusano, K. et al. Magnetic field structures triggering solar flares and coronal mass ejections. Astrophys. J. 760, 31 (2012).
Janvier, M., Aulanier, G. & Démoulin, P. From coronal observations to MHD simulations, the building blocks for 3D models of solar flares (invited review). Solar Phys. 290, 3425–3456 (2015).
Kleint, L. et al. The fast filament eruption leading to the X-flare on 2014 March 29. Astrophys. J. 806, 9 (2015).
Young, P. R., Tian, H. & Jaeggli, S. The 2014 March 29 X-flare: subarcsecond resolution observations of Fe XXI λ1354.1. Astrophys. J. 799, 218 (2015).
Rempel, M. Extension of the MURaM radiative MHD code for coronal simulations. Astrophys. J. 834, 10 (2017).
Archontis, V. & Török, T. Eruption of magnetic flux ropes during flux emergence. Astron. Astrophys. 492, L35–L38 (2008).
Aulanier, G., Török, T., Démoulin, P. & DeLuca, E. E. Formation of torus-unstable flux ropes and electric currents in erupting sigmoids. Astrophys. J. 708, 314–333 (2010).
Cheng, X., Zhang, J., Liu, Y. & Ding, M. D. Observing flux rope formation during the impulsive phase of a solar eruption. Astrophys. J. Lett. 732, L25 (2011).
Nindos, A., Patsourakos, S., Vourlidas, A. & Tagikas, C. How common are hot magnetic flux ropes in the low solar corona? A statistical study of EUV observations. Astrophys. J. 808, 117 (2015).
Yokoyama, T. & Shibata, K. Magnetohydrodynamic simulation of a solar flare with chromospheric evaporation effect based on the magnetic reconnection model. Astrophys. J. 549, 1160–1174 (2001).
Reep, J. W., Bradshaw, S. J. & Alexander, D. Optimal electron energies for driving chromospheric evaporation in solar flares. Astrophys. J. 808, 177 (2015).
Fletcher, L. & Hudson, H. S. Impulsive phase flare energy transport by large-scale Alfvén waves and the electron acceleration problem. Astrophys. J. 675, 1645–1655 (2008).
Kowalski, A. F., Allred, J. C., Daw, A., Cauzzi, G. & Carlsson, M. The atmospheric response to high nonthermal electron beam fluxes in solar flares. I. Modeling the brightest NUV footpoints in the X1 solar flare of 2014 March 29. Astrophys. J. 836, 12 (2017).
Del Zanna, G., Schmieder, B., Mason, H., Berlicki, A. & Bradshaw, S. The gradual phase of the X17 flare on October 28, 2003. Solar Phys. 239, 173–191 (2006).
Milligan, R. O. & Dennis, B. R. Velocity characteristics of evaporated plasma using hinode/EUV imaging spectrometer. Astrophys. J. 699, 968–975 (2009).
Jeffrey, N. L. S., Fletcher, L. & Labrosse, N. First evidence of non-Gaussian solar flare EUV spectral line profiles and accelerated non-thermal ion motion. Astron. Astrophys. 590, A99 (2016).
Liu, W., Petrosian, V., Dennis, B. R. & Jiang, Y. W. Double coronal hard and soft X-ray source observed by RHESSI: evidence for magnetic reconnection and particle acceleration in solar flares. Astrophys. J. 676, 704–716 (2008).
Krucker, S. & Battaglia, M. Particle densities within the acceleration region of a solar flare. Astrophys. J. 780, 107 (2014).
Boris, J. P. A Physically Motivated Solution of the Alfvén Problem NRL Memorandum Report 2167 (Naval Research Laboratory, 1970).
Gombosi, T. I. et al. Semirelativistic magnetohydrodynamics and physics-based convergence acceleration. J. Comput. Phys. 177, 176–205 (2002).
Gombosi, T. I., Jokipii, J. R., Kota, J., Lorencz, K. & Williams, L. L. The telegraph equation in charged particle transport. Astrophys. J. 403, 377–384 (1993).
Snodin, A. P., Brandenburg, A., Mee, A. J. & Shukurov, A. Simulating field-aligned diffusion of a cosmic ray gas. Mon. Not. R. Astron. Soc. 373, 643–652 (2006).
Rempel, M. Numerical simulations of quiet Sun magnetism: on the contribution from a small-scale dynamo. Astrophys. J. 789, 132 (2014).
Judge, P. G., Kleint, L., Donea, A., Sainz Dalda, A. & Fletcher, L. On the origin of a sunquake during the 2014 March 29X1 flare. Astrophys. J. 796, 85 (2014).
Yang, K., Guo, Y. & Ding, M. D. Quantifying the topology and evolution of a magnetic flux rope associated with multi-flare activities. Astrophys. J. 824, 148 (2016).
Li, Y., Ding, M. D., Qiu, J. & Cheng, J. X. Chromospheric evaporation in an X1.0 flare on 2014 March 29 observed with IRIS and EIS. Astrophys. J. 811, 7 (2015).
Rubio da Costa, F., Kleint, L., Petrosian, V., Liu, W. & Allred, J. C. Data-driven radiative hydrodynamic modeling of the 2014 March 29 X1.0 solar flare. Astrophys. J. 827, 38 (2016).
Liu, C. et al. A circular-ribbon solar flare following an asymmetric filament eruption. Astrophys. J. Lett. 812, L19 (2015).
Fan, Y. The emergence of a twisted flux tube into the solar atmosphere: sunspot rotations and the formation of a coronal flux rope. Astrophys. J. 697, 1529–1542 (2009).
Manchester, W. B. IV Solar atmospheric dynamic coupling due to shear motions driven by the Lorentz force. Astrophys. J. 666, 532–540 (2007).
Antiochos, S. K., DeVore, C. R. & Klimchuk, J. A. A model for solar coronal mass ejections. Astrophys. J. 510, 485–493 (1999).
Lynch, B. J., Antiochos, S. K., DeVore, C. R., Luhmann, J. G. & Zurbuchen, T. H. Topological evolution of a fast magnetic breakout CME in three dimensions. Astrophys. J. 683, 1192–1206 (2008).
Manchester, W. B. IV, Gombosi, T., DeZeeuw, D. & Fan, Y. Eruption of a buoyantly emerging magnetic flux rope. Astrophys. J. 610, 588–596 (2004).
Jiang, C. et al. Data-driven magnetohydrodynamic modelling of a flux-emerging active region leading to solar eruption. Nat. Commun. 7, 11522 (2016).
Hansteen, V. H., Hara, H., De Pontieu, B. & Carlsson, M. On redshifts and blueshifts in the transition region and corona. Astrophys. J. 718, 1070–1078 (2010).
Cheung, M. C. M. & DeRosa, M. L. A method for data-driven simulations of evolving solar active regions. Astrophys. J. 757, 147 (2012).
Cheung, M. C. M. et al. Homologous helical jets: observations by IRIS, SDO, and Hinode and magnetic modeling with data-driven simulations. Astrophys. J. 801, 83 (2015).
Vögler, A. et al. Simulations of magneto-convection in the solar photosphere. Equations, methods, and results of the MURaM code. Astron. Astrophys. 429, 335–351 (2005).
Acknowledgements
The authors acknowledge support from NASA's Heliophysics Grand Challenges Research grant 'Physics and Diagnostics of the Drivers of Solar Eruptions' (NNX14AI14G to the LMSAL). M.R. is supported by NASA grant NNX13AK54G. F.C. and A.M. are supported by the Advanced Study Program postdoctoral fellowship at NCAR. NCAR is sponsored by the National Science Foundation. We acknowledge high-performance computing support from Cheyenne (https://doi.org/10.5065/D6RX99HX), provided by NCAR's Computational and Information Systems Laboratory and sponsored by the National Science Foundation, as well as from the NASA High-End Computing programme through the NASA Advanced Supercomputing Division at Ames Research Center. Data are courtesy of the science teams of the SDO and IRIS. M.C.M.C., G.C., M.L.D. and B.D.P. acknowledge support from NASA's SDO/AIA (NNG04EA00C) contract to the LMSAL. P.T. acknowledges support from contracts 4101946323, 8100002705 and SP02H1701R from Lockheed Martin, and NASA contract NNM07AB07C, to the SAO. The AIA and Helioseismic and Magnetic Imager are instruments onboard the SDO—a mission for NASA's Living With a Star Program. IRIS is a NASA small explorer mission, developed and operated by the LMSAL, with mission operations executed at the NASA Ames Research Center, and major contributions to downlink communications funded by the Norwegian Space Center through an ESA PRODEX contract. This work is supported by NASA under contract NNG09FA40C (IRIS), European Research Council grant agreement number 291058 and contract 8100002705 from the LMSAL to the SAO. This research was also supported by the Research Council of Norway through grant 170935/V30.
Author information
Authors and Affiliations
Contributions
M.C.M.C. wrote code to synthesize and analyse remote sensing diagnostics from the numerical simulation, analysed SDO and IRIS data, managed the team of co-authors and contributed to writing the text. M.R. implemented the coronal extension of the MURaM radiative MHD code, conducted the MHD simulations, and contributed to data analysis and writing of the paper. G.C., M.L.D., V.H. and A.M. performed the analysis on the magnetic evolution of the simulated flare. F.C. performed the analysis on X-ray fluxes from the simulation. A.S.D. performed analysis on photospheric magnetic observables. P.T., B.D.P., M.C. and S.W.M. performed analysis on optically thin X-ray and EUV emission, and contributed to the text. J.M.-S. performed the analysis and wrote the text for the section on κ versus Gaussian distributions. M.C., B.G. and V.H. contributed to the extension of the numerical model to couple the convection zone with the atmosphere.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Supplementary Information
Supplementary Figures 1–9, captions of Supplementary Videos 1–6
Supplementary Video 1
Animation of Fig. 2
Supplementary Video 2
Animation of Fig. 3
Supplementary Video 3
Animation of panel a of Supplementary Figure 1
Supplementary Video 4
Animation of Supplementary Figure 5
Supplementary Video 5
Animation of Supplementary Figure 7
Supplementary Video 6
Animation of Supplementary Figure 8
Rights and permissions
About this article
Cite this article
Cheung, M.C.M., Rempel, M., Chintzoglou, G. et al. A comprehensive three-dimensional radiative magnetohydrodynamic simulation of a solar flare. Nat Astron 3, 160–166 (2019). https://doi.org/10.1038/s41550-018-0629-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41550-018-0629-3
This article is cited by
-
Forecasting Solar Flares by Data Assimilation in Sandpile Models
Solar Physics (2022)
-
Magnetic imaging of the outer solar atmosphere (MImOSA)
Experimental Astronomy (2022)
-
On the Hemispheric Bias Seen in Vector Magnetic Field Data
Solar Physics (2022)
-
Magnetohydrostatic modeling of the solar atmosphere
Science China Technological Sciences (2022)
-
Solar X-ray and EUV imager on board the FY-3E satellite
Light: Science & Applications (2022)