Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

A basal contribution from p-modes to the Alfvénic wave flux in the Sun’s corona


Many cool stars possess complex magnetic fields1 that are considered to undertake a central role in the structuring and energizing of their atmospheres2. Alfvénic waves are thought to make a critical contribution to energy transfer along these magnetic fields, with the potential to heat plasma and accelerate stellar winds3,4,5. Despite Alfvénic waves having been identified in the Sun’s atmosphere, the nature of the basal wave energy flux is poorly understood. It is generally assumed that the associated Poynting flux is generated solely in the photosphere and propagates into the corona, typically through the continuous buffeting of magnetic fields by turbulent convective cells4,6,7. Here, we provide evidence that the Sun’s internal acoustic modes also contribute to the basal flux of Alfvénic waves, delivering a spatially ubiquitous input to the coronal energy balance that is sustained over the solar cycle. Alfvénic waves are thus a fundamental feature of the Sun’s corona. Acknowledging that internal acoustic modes have a key role in injecting additional Poynting flux into the upper atmospheres of Sun-like stars has potentially significant consequences for the modelling of stellar coronae and winds.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Signature of coronal Alfvénic waves.
Fig. 2: Properties of Alfvénic waves throughout the corona.
Fig. 3: Power spectra parameter distributions for Alfvénic waves.
Fig. 4: Global measures of Alfvénic waves through the solar cycle.

Similar content being viewed by others

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request. The SDO data are available from the Joint Science Operations Center ( The CoMP data are available from the High Altitude Observatory data repository (


  1. Reiners, A. Observations of cool-star magnetic fields. Living Rev. Sol. Phys. 9, 1 (2012).

    Article  ADS  Google Scholar 

  2. Testa, P., Saar, S. H. & Drake, J. J. Stellar activity and coronal heating: an overview of recent results. Phil. Trans. R. Soc. A 373, 20140259 (2015).

    Article  ADS  Google Scholar 

  3. Narain, U. & Ulmschneider, P. Chromospheric and coronal heating mechanisms II. Space Sci. Rev. 75, 453–509 (1996).

    Article  ADS  Google Scholar 

  4. Suzuki, T. K. & Inutsuka, S. Making the corona and the fast solar wind: a self-consistent simulation for the low-frequency Alfvén waves from the photosphere to 0.3au. Astrophys. J. 632, L49–L52 (2005).

    Article  ADS  Google Scholar 

  5. Verdini, A. & Velli, M. Alfvén waves and turbulence in the solar atmosphere and solar wind. Astrophys. J. 662, 669–676 (2007).

    Article  ADS  Google Scholar 

  6. Cranmer, S. R. & van Ballegooijen, A. A. On the generation, propagation, and reflection of Alfvén waves from the solar photosphere to the distant heliosphere. Astrophys. J. Suppl. Ser. 156, 265–293 (2005).

    Article  ADS  Google Scholar 

  7. Van Ballegooijen, A. A., Asgari-Targhi, M., Cranmer, S. R. & DeLuca, E. E. Heating of the solar chromosphere and corona by Alfvén wave turbulence. Astrophys. J. 736, 3 (2011).

    Article  ADS  Google Scholar 

  8. Belcher, J. W. & Davis, L. J. Large-amplitude Alfvén waves in the interplanetary medium 2. J. Geophys. Res. 76, 3534–3563 (1971).

    Article  ADS  Google Scholar 

  9. Bruno, R. & Carbone, V. The solar wind as a turbulence laboratory. Living Rev. Sol. Phys. 2, 4 (2005).

    Article  ADS  Google Scholar 

  10. Banerjee, D., Teriaca, L., Doyle, J. G. & Wilhelm, K. Broadening of SI VIII lines observed in the solar polar coronal holes. Astron. Astrophys. 339, 208–214 (1998).

    ADS  Google Scholar 

  11. Tomczyk, S. et al. Alfvén waves in the solar corona. Science 317, 1192–1196 (2007).

    Article  ADS  Google Scholar 

  12. De Pontieu, B. et al. Chromospheric Alfvénic waves strong enough to power the solar wind. Science 318, 1574–1577 (2007).

    Article  ADS  Google Scholar 

  13. Morton, R. J., Tomczyk, S. & Pinto, R. F. Investigating Alfvénic wave propagation in coronal open-field regions. Nat. Commun. 6, 7813 (2015).

    Article  ADS  Google Scholar 

  14. Morton, R. J., Tomczyk, S. & Pinto, R. F. A global view of velocity fluctuations in the corona below 1.3 R with CoMP. Astrophys. J. 828, 89 (2016).

    Article  ADS  Google Scholar 

  15. Van Doorsselaere, T., Nakariakov, V. M. & Verwichte, E. Detection of waves in the solar corona: kink or Alfvén? Astrophys. J. Lett. 676, L73 (2008).

    Article  ADS  Google Scholar 

  16. McIntosh, S. W. et al. Alfvénic waves with sufficient energy to power the quiet solar corona and fast solar wind. Nature 475, 447–480 (2011).

    Article  ADS  Google Scholar 

  17. Thurgood, J. O., Morton, R. J. & McLaughlin, J. A. First direct measurements of transverse waves in solar polar plumes using SDO/AIA. Astrophys. J. 790, L2 (2014).

    Article  ADS  Google Scholar 

  18. Cally, P. S. & Goossens, M. Three-dimensional MHD wave propagation and conversion to Alfvén waves near the solar surface. I. Direct numerical solution. Sol. Phys. 251, 251–265 (2008).

    Article  ADS  Google Scholar 

  19. Cally, P. S. & Hansen, S. C. Benchmarking fast-to-Alfvén mode conversion in a cold magnetohydrodynamic plasma. Astrophys. J. 738, 119 (2011).

    Article  ADS  Google Scholar 

  20. Cally, P. S. Alfvén waves in the structured solar corona. Mon. Not. R. Astron. Soc. 466, 413–424 (2017).

    Article  ADS  Google Scholar 

  21. Jefferies, S. M. et al. Magnetoacoustic portals and the basal heating of the solar chromosphere. Astrophys. J. 648, L151–L155 (2006).

    Article  ADS  Google Scholar 

  22. Matthaeus, W. H., Zank, G. P., Oughton, S., Mullan, D. J. & Dmitruk, P. Coronal heating by magnetohydrodynamic turbulence driven by reflected low-frequency waves. Astrophys. J. 523, L93–L96 (1999).

    Article  ADS  Google Scholar 

  23. Bavassano, B., Dobrowolny, M., Mariani, F. & Ness, N. F. Radial evolution of power spectra of interplanetary Alfvénic turbulence. J. Geophys. Res. 87, 3617–3622 (1982).

    Article  ADS  Google Scholar 

  24. Pandey, B. P., Vranjes, J. & Krishan, V. Waves in the solar photosphere. Mon. Not. R. Astron. Soc. 386, 1635–1643 (2008).

    Article  ADS  Google Scholar 

  25. Soler, R., Ballester, J. L. & Zaqarashvili, T. V. Overdamped Alfvén waves due to ion-neutral collisions in the solar chromosphere. Astron. Astrophys. 573, 79 (2015).

    Article  ADS  Google Scholar 

  26. Arber, T. D., Brady, C. S. & Shelyag, S. Alfvén wave heating of the solar chromosphere: 1.5D models. Astrophys. J. 817, 94 (2016).

    Article  ADS  Google Scholar 

  27. Morgan, H. & Taroyan, Y. Global conditions in the solar corona from 2010 to 2017. Sci. Adv. 3, e1602056 (2017).

    Article  ADS  Google Scholar 

  28. McIntosh, S. W. & De Pontieu, B. Estimating the “dark” energy content of the solar corona. Astrophys. J. 761, 138 (2012).

    Article  ADS  Google Scholar 

  29. Chaplin, W. J. & Miglio, A. Asteroseismology of solar-type and red-giant stars. Annu. Rev. Astron. Astrophys. 51, 353–392 (2013).

    Article  ADS  Google Scholar 

  30. Tomczyk, S. et al. An instrument to measure coronal emission line polarization. Sol. Phys. 247, 411–428 (2008).

    Article  ADS  Google Scholar 

  31. Lemen, J. R. et al. The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Sol. Phys. 275, 17–40 (2012).

    Article  ADS  Google Scholar 

  32. Goossens, M., Terradas, J., Andries, J., Arregui, I. & Ballester, J. L. On the nature of kink MHD waves in magnetic flux tubes. Astron. Astrophys. 503, 213–223 (2009).

    Article  ADS  Google Scholar 

  33. Goossens, M. et al. Surface Alfvén waves in solar flux tubes. Astrophys. J. 753, 111 (2012).

    Article  ADS  Google Scholar 

  34. Weberg, M., Morton, R. J. & McLaughlin, J. A. An automated algorithm for identifying and tracking transverse waves in solar images. Astrophys. J. 852, 57 (2018).

    Article  ADS  Google Scholar 

  35. Vaughan, S. A simple test for periodic signals in red noise. Astron. Astrophys. 431, 391–403 (2005).

    Article  ADS  Google Scholar 

  36. Ireland, J., McAteer, R. T. J. & Inglis, A. R. Coronal Fourier power spectra: implications for coronal seismology and coronal heating. Astrophys. J. 798, 12 (2015).

    Google Scholar 

  37. Feigelson, E. & Babu, G. J. Modern Statistical Methods for Astronomy (Cambridge Univ. Press, Cambridge, 2012).

  38. De Pontieu, B. et al. The origins of hot plasma in the solar corona. Science 331, 55–58 (2011).

    Article  ADS  Google Scholar 

Download references


All authors acknowledge that this material is based on work supported by the Air Force Office of Scientific Research, Air Force Material Command, USAF under award number FA9550-16-1-0032, and the Science and Technology Facilities Council via grant number ST/L006243/1. R.J.M. is grateful to the Leverhulme Trust for the award of an Early Career Fellowship, and the High Altitude Observatory for financial assistance. M.J.W. acknowledges additional support from NASA grant NNH16AC39I and basic research funds from the Chief of Naval Research. R.J.M. is also grateful for discussions at ISSI, Bern (Towards Dynamic Solar Atmospheric Magneto-Seismology with New Generation Instrumentation) and with G. Li and S. Tomczyk. The authors acknowledge the work of the NASA/SDO and AIA science teams, and National Center for Atmospheric Research/High Altitude Observatory CoMP instrument team.

Author information

Authors and Affiliations



R.J.M. performed the analysis of the CoMP data. R.J.M., M.J.W. and J.A.M. performed the analysis of the SDO data. All authors discussed the results and contributed to the writing of the manuscript.

Corresponding author

Correspondence to R. J. Morton.

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 Text, Supplementary Tables 1–3, Supplementary References

Supplementary Table 2

Extended readable version of Supplementary Table 2

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Morton, R.J., Weberg, M.J. & McLaughlin, J.A. A basal contribution from p-modes to the Alfvénic wave flux in the Sun’s corona. Nat Astron 3, 223–229 (2019).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing