Skip to main content

Thank you for visiting nature.com. 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.

Alfvénic waves with sufficient energy to power the quiet solar corona and fast solar wind

Subjects

Abstract

Energy is required to heat the outer solar atmosphere to millions of degrees (refs 1, 2) and to accelerate the solar wind to hundreds of kilometres per second (refs 2–6). Alfvén waves (travelling oscillations of ions and magnetic field) have been invoked as a possible mechanism to transport magneto-convective energy upwards along the Sun’s magnetic field lines into the corona. Previous observations7 of Alfvénic waves in the corona revealed amplitudes far too small (0.5 km s−1) to supply the energy flux (100–200 W m−2) required to drive the fast solar wind8 or balance the radiative losses of the quiet corona9. Here we report observations of the transition region (between the chromosphere and the corona) and of the corona that reveal how Alfvénic motions permeate the dynamic and finely structured outer solar atmosphere. The ubiquitous outward-propagating Alfvénic motions observed have amplitudes of the order of 20 km s−1 and periods of the order of 100–500 s throughout the quiescent atmosphere (compatible with recent investigations7,10), and are energetic enough to accelerate the fast solar wind and heat the quiet corona.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Ubiquitous Alfvénic motion above the solar limb.
Figure 2: Examining Alfvénic motion in coronal hole (top row) and quiet Sun (bottom row) regions.
Figure 3: Examining Alfvénic motion in an active region of the Sun.
Figure 4: Determining the phase speed of the Alfvénic motions.

References

  1. Belcher, J. W. & Olbert, S. Stellar winds driven by Alfvén waves. Astrophys. J. 200, 369–382 (1975)

    Article  ADS  Google Scholar 

  2. Axford, W. I. et al. Acceleration of the high speed solar wind in coronal holes. Space Sci. Rev. 87, 25–41 (1999)

    Article  ADS  CAS  Google Scholar 

  3. 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–L97 (1999)

    Article  ADS  Google Scholar 

  4. Cranmer, S. R., van Ballegooijen, A. A. & Edgar, R. J. Self-consistent coronal heating and solar wind acceleration from anisotropic magnetohydrodynamic turbulence. Astrophys. J. 171 (Suppl.). 520–551 (2007)

    Article  ADS  CAS  Google Scholar 

  5. Suzuki, T. K. & Inutsuka, S.-i. Solar winds driven by nonlinear low-frequency Alfvén waves from the photosphere: parametric study for fast/slow winds and disappearance of solar winds. J. Geophys. Res. 111 A06101 10.1029/2005JA011502 (2006)

    Article  ADS  Google Scholar 

  6. Verdini, A., Velli, M., Matthaeus, W. H., Oughton, S. & Dmitruk, P. A turbulence-driven model for heating and acceleration of the fast wind in coronal holes. Astrophys. J. 708, L116–L120 (2010)

    Article  ADS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  8. Hansteen, V. H. & Leer, E. Coronal heating, densities, and temperatures and solar wind acceleration. J. Geophys. Res. 100, 21577–21593 (1995)

    Article  ADS  Google Scholar 

  9. Withbroe, G. L. & Noyes, R. W. Mass and energy flow in the solar chromosphere and corona. Annu. Rev. Astron. Astrophys. 15, 363–387 (1977)

    Article  ADS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  11. Tsuneta, S. et al. The solar optical telescope for the Hinode mission: an overview. Sol. Phys. 249, 167–196 (2008)

    Article  ADS  Google Scholar 

  12. Beckers, J. M. Solar spicules. Sol. Phys. 3, 367–433 (1968)

    ADS  Google Scholar 

  13. De Pontieu, B. et al. A tale of two spicules: the impact of spicules on the magnetic chromosphere. Publ. Astron. Soc. Jpn 59, 655–662 (2007)

    Article  Google Scholar 

  14. Lemen, J. R. et al. The Atmospheric Imaging Assembly on the Solar Dynamics Observatory. Sol. Phys. (submitted)

  15. De Pontieu, B. et al. The origin of hot coronal plasma. Science 331, 55–58 (2011)

    Article  ADS  CAS  Google Scholar 

  16. De Pontieu, B., McIntosh, S. W., Hansteen, V. H. & Schrijver, C. J. Observing the roots of solar coronal heating—in the chromosphere. Astrophys. J. 701, L1–L6 (2009)

    Article  ADS  CAS  Google Scholar 

  17. Tomczyk, S. & McIntosh, S. W. Time-distance seismology of the solar corona with CoMP. Astrophys. J. 697, 1384–1391 (2009)

    Article  ADS  Google Scholar 

  18. Patsourakos, S. & Klimchuk, J. A. Nonthermal spectral line broadening and the nanoflare model. Astrophys. J. 647, 1452–1465 (2006)

    Article  ADS  CAS  Google Scholar 

  19. McIntosh, S. W. et al. Observations supporting the role of magnetoconvection in energy supply to the quiescent solar atmosphere. Astrophys. J. 654, 650–664 (2007)

    Article  ADS  CAS  Google Scholar 

  20. McIntosh, S. W., Leamon, R. J. & De Pontieu, B. The spectroscopic footprint of the fast solar wind. Astrophys. J. 727, 7 (2011)

    Article  ADS  Google Scholar 

  21. Hollweg, J. V. Alfvén waves in a two-fluid model of the solar wind. Astrophys. J. 181, 547–566 (1973)

    Article  ADS  CAS  Google Scholar 

  22. Chandran, B. D. G. Alfvén-wave turbulence and perpendicular ion temperatures in coronal holes. Astrophys. J. 720, 548–554 (2010)

    Article  ADS  CAS  Google Scholar 

  23. Cranmer, S. R. & van Ballegooijen, A. A. Can the solar wind be driven by magnetic reconnection in the Sun's magnetic carpet? Astrophys. J. 720, 824–847 (2010)

    Article  ADS  Google Scholar 

Download references

Acknowledgements

SDO is the first mission of NASA’s Living With a Star Program. NCAR is sponsored by the NSF.

Author information

Authors and Affiliations

Authors

Contributions

S.W.M. (with B.D.P. and M.C.) performed all image processing and analysis of observations. S.W.M. and M.C. calculated phase speeds. P.B. (with B.D.P. and V.H.H.) designed the special observing sequences. B.D.P. co-aligned the data, performed Monte Carlo simulations (with V.H.H.) and provided density estimates. M.G. assisted with the identification of the wave mode. S.W.M. and B.D.P. wrote the manuscript. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Scott W. McIntosh.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

The file contains Supplementary Figures 1-5 with legends, Supplementary Text and Supplementary Table 1. (PDF 11819 kb)

Supplementary Movie 1

This movie shows SDO/AIA 304Å observations of a polar coronal hole showing the continuous transverse motion of spicules. The movie covers the entire 75 minutes of the observations studied. (MOV 3670 kb)

Supplementary Movie 2

This movie shows unsharp masked SDO/AIA 171Å observations of a polar coronal hole showing the continuous transverse motion of propagating disturbances. The movie covers the entire 75 minutes of the observations studied. (MOV 9909 kb)

Supplementary Movie 3

This movie shows SDO/AIA 304Å (left) and 171Å (right) observations of a small portion of a polar coronal hole showing the continuous transverse motion of spicules and propagating disturbances as we move upward from the limb. Top row shows the raw data and the bottom row show the respective unsharp masked data. (MOV 5858 kb)

Supplementary Movie 4

This movie shows SDO/AIA 304Å (left) and 171Å (right) observations of a small portion of a quiet Sun showing the continuous transverse motion of spicules and propagating disturbances as we move upward from the limb. Top row shows the raw data and the bottom row show the respective unsharp masked data. (MOV 8494 kb)

Supplementary Movie 5

This movie shows SDO/AIA 171Å observations of an active region showing the continuous transverse motion of the coronal loop system. The region in the box is cut-out for closer inspection and presented in SI Movie 7. The movie covers the entire 75 minutes of the observations studied. (MOV 1949 kb)

Supplementary Movie 6

This movie shows the unsharp masked SDO/AIA 171Å observations of an active region showing the continuous transverse motion of the coronal loop system. The region in the box is cut-out for closer inspection and presented in SI Movie 7. The movie covers the entire 75 minutes of the observations studied. (MOV 10838 kb)

Supplementary Movie 7

This movie shows the loop waves and evolution from SDO/AIA 171Å observations of an active region coronal loop system in the raw data (left) and unsharp-masked to remove the background emission (right). The movie covers the entire 75 minutes of the observations studied. (MOV 2487 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

McIntosh, S., De Pontieu, B., Carlsson, M. et al. Alfvénic waves with sufficient energy to power the quiet solar corona and fast solar wind. Nature 475, 477–480 (2011). https://doi.org/10.1038/nature10235

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature10235

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

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