Letter

The detection of Rossby-like waves on the Sun

  • Nature Astronomy 1, Article number: 0086 (2017)
  • doi:10.1038/s41550-017-0086
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Abstract

Rossby waves are a type of global-scale wave that develops in planetary atmospheres, driven by the planet’s rotation1. They propagate westward owing to the Coriolis force, and their characterization enables more precise forecasting of weather on Earth2,3. Despite the massive reservoir of rotational energy available in the Sun’s interior and decades of observational investigation, their solar analogue defies unambiguous identification4,​5,​6. Here we analyse a combined set of images obtained by the Solar TErrestrial RElations Observatory (STEREO) and the Solar Dynamics Observatory (SDO) spacecraft between 2011 and 2013 in order to follow the evolution of small bright features, called brightpoints, which are tracers of rotationally driven large-scale convection7. We report the detection of persistent, global-scale bands of magnetized activity on the Sun that slowly meander westward in longitude and display Rossby-wave-like behaviour. These magnetized Rossby waves allow us to make direct connections between decadal-scale solar activity and that on much shorter timescales. Monitoring the properties of these waves, and the wavenumber of the disturbances that they generate, has the potential to yield a considerable improvement in forecast capability for solar activity and related space weather phenomena.

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References

  1. 1.

    et al. Relation between variations in the intensity of the zonal circulation of the atmosphere and the semi-permanent centers of action. J. Mar. Res. 2, 38–55 (1939).

  2. 2.

    On the existence of extended range predictability. J. Appl. Meteorol. 12, 543–546 (1973).

  3. 3.

    & Atmospheric predictability and Rossby wave packets. Q. J. R. Meteorol. Soc. 141, 2793–2802 (2015).

  4. 4.

    , , & Rossby waves on the Sun as revealed by solar ‘hills’. Nature 405, 544–546 (2000).

  5. 5.

    et al. Long-term variation in the Sun’s activity caused by magnetic Rossby waves in the tachocline. Astrophys. J. Lett. 805, 14 (2015).

  6. 6.

    et al. The solar magnetic activity band interaction and instabilities that shape quasi-periodic variability. Nat. Commun. 6, 6491 (2015).

  7. 7.

    , , & Identifying potential markers of the Sun’s giant convective scale. Astrophys. J. Lett. 784, L32 (2014).

  8. 8.

    et al. Deciphering solar magnetic activity. I. On the relationship between the sunspot cycle and the evolution of small magnetic features. Astrophys. J. 792, 12 (2014).

  9. 9.

    & Nine years of EUV bright points. Sol. Phys. 228, 285–299 (2005).

  10. 10.

    et al. Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI). Space Sci. Rev. 136, 67–115 (2008).

  11. 11.

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

  12. 12.

    The trough-and-ridge diagram. Tellus 1, 62–66 (1949).

  13. 13.

    & Solar-cycle characteristics examined in separate hemispheres: phase, Gnevyshev gap, and length of minimum. Sol. Phys. 261, 193–207 (2010).

  14. 14.

    et al. Hemispheric asymmetries of solar photospheric magnetism: radiative, particulate, and heliospheric impacts. Astrophys. J. 765, 146 (2013).

  15. 15.

    , & Giant convection cells found on the Sun. Science 342, 1217–1219 (2013).

  16. 16.

    & A shallow-water theory for the Sun’s active longitudes. Astrophys. J. 635, L193–L196 (2005).

  17. 17.

    , , & Magnetic Rossby waves in the solar tachocline and Rieger-type periodicities. Astrophys. J. 709, 749–758 (2010).

  18. 18.

    & Nonlinear wave interactions in shallow water magnetohydrodynamics of astrophysical plasma. J. Exp. Theor. Phys. 122, 832–848 (2016).

  19. 19.

    On the probable existence of a magnetic field in sun-spots. Astrophys. J. 28, 315–343 (1908).

  20. 20.

    & Time–distance seismology of the solar corona with CoMP. Astrophys. J. 697, 1384–1391 (2009).

  21. 21.

    Rossby waves — long period oscillations of oceans and atmospheres. Annu. Rev. Fluid. Mech. 10, 159–195 (1978).

  22. 22.

    Very long lived wave patterns detected in the solar surface velocity signal. Astrophys. J. 560, 466–475 (2001).

  23. 23.

    & The Sun is observed to be a torsional oscillator with a period of 11 years. Astrophys. J. Lett. 239, 33–36 (1980).

  24. 24.

    et al. The extended solar activity cycle. Nature 333, 748–750 (1998).

  25. 25.

    et al. Utility of Hovmöller diagrams to diagnose Rossby wave trains. Tellus A 63, 991–1006 (2011).

  26. 26.

    , , & Long-term persistence of solar active longitudes and its implications for the solar dynamo theory. Adv. Space Res. 40, 951–958 (2007).

  27. 27.

    et al. A 154-day periodicity in the occurrence of hard solar flares? Nature 312, 623–625 (1984).

  28. 28.

    & Study of the development of active regions on the Sun. Astrophys. J. 141, 1492–1501 (1965).

  29. 29.

    On the evidence which the observed motions of the solar spots offer for the existence of an atmosphere surrounding the Sun. Mon. Not. R. Astron. Soc. 18, 169–177 (1858).

  30. 30.

    , & Sunspot nests: manifestations of sequences in magnetic activity. Sol. Phys. 105, 237–255 (1986).

  31. 31.

    & Sunspot nests as traced by a cluster analysis. Sol. Phys. 129, 221–246 (1990).

  32. 32.

    et al. Rieger-type periodicity during solar cycles 14–24: estimation of dynamo magnetic field strength in the solar interior. Astrophys. J. 826, 55 (2016).

  33. 33.

    et al. Understanding space weather to shield society: a global road map for 2015–2025 commissioned by COSPAR and ILWS. Adv. Space Res. 55, 2745–2807 (2015).

  34. 34.

    TIROS experiment results. Space Sci. Rev. 1, 7–27 (1962).

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Acknowledgements

The National Center for Atmospheric Research is sponsored by the National Science Foundation and the compilation of feature databases used was supported by NASA grant NNX08AU30G. W.J.C. and M.P.M. were supported by NSF REU grant 1157020 to the University of Colorado.

Author information

Affiliations

  1. High Altitude Observatory, National Center for Atmospheric Research, PO Box 3000, Boulder, Colorado 80307, USA.

    • Scott W. McIntosh
  2. Department of Astronomy, Yale University, PO Box 208101, New Haven, Connecticut 06520, USA.

    • William J. Cramer
  3. Department of Physics, Texas Tech University, Box 41051, Lubbock, Texas 79409, USA.

    • Manuel Pichardo Marcano
  4. Department of Astronomy, University of Maryland College Park, Maryland 20742, USA.

    • Robert J. Leamon

Authors

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Contributions

S.W.M. contributed to data collection, data reduction, initial data analysis, manuscript writing and presentation. W.J.C. and M.P.M. contributed to data analysis and concatenation, code development and manuscript editing. R.J.L. contributed to data analysis, data interpretation and manuscript editing.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Scott W. McIntosh.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    Supplementary Figures 1–3 and Supplementary Videos 1–5 captions.

Videos

  1. 1.

    Supplementary Video 1

    Longitude-latitude variation of the SDO/AIA and STEREO/EUVI brightpoints identification from 1 June 2010 to 31 May 2013.

  2. 2.

    Supplementary Video 2

    Longitude-latitude variation of the AIA/EUVI brightpoints density distribution from 1 June 2010 to 31 May 2013.

  3. 3.

    Supplementary Video 3

    Pole-on projection for the AIA/EUVI brightpoints density distribution in the southern solar hemisphere.

  4. 4.

    Supplementary Video 4

    Pole-on projection for the AIA/EUVI brightpoints density distribution in the northern solar hemisphere.

  5. 5.

    Supplementary Video 5

    Latitude versus time variation of the 28-day-averaged AIA/EUVI brightpoints density at different solar longitudes