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Solar Physics

, Volume 290, Issue 11, pp 3095–3111 | Cite as

A Comparison Between Global Proxies of the Sun’s Magnetic Activity Cycle: Inferences from Helioseismology

  • A.-M. Broomhall
  • V. M. Nakariakov
Probing the Sun: Inside and Out

Abstract

The last solar minimum was, by recent standards, unusually deep and long. We are now close to the maximum of the subsequent solar cycle, which is relatively weak. In this article we make comparisons between different global (unresolved) measures of the Sun’s magnetic activity to investigate how they are responding to this weak-activity epoch. We focus on helioseismic data, which are sensitive to conditions, including the characteristics of the magnetic field, in the solar interior. Also considered are measures of the magnetic field in the photosphere (sunspot number and sunspot area), the chromosphere and corona (10.7 cm radio flux and 530.3 nm green coronal index), and two measures of the Sun’s magnetic activity closer to Earth (the interplanetary magnetic field and the galactic cosmic-ray intensity). Scaled versions of the activity proxies diverge from the helioseismic data around 2000, indicating a change in relationship between the proxies. The degree of divergence varies from proxy to proxy, with sunspot area and 10.7 cm flux showing only small deviations, while sunspot number, coronal index, and the two interplanetary proxies show much larger departures. In Cycle 24 the deviations in the solar proxies and the helioseismic data decrease, raising the possibility that the deviations observed in Cycle 23 are just symptomatic of a 22-year Hale cycle. However, the deviations in the helioseismic data and the interplanetary proxies increase in Cycle 24. Interestingly, the divergence in the solar proxies and the helioseismic data are not reflected in the shorter-term variations (often referred to as quasi-biennial oscillations) observed on top of the dominant 11-year solar cycle. However, despite being highly correlated in Cycle 22, the short-term variations in the interplanetary proxies show very little correlation with the helioseismic data during Cycles 23 and 24.

Keywords

Helioseismology, Observations Integrated Sun Observations Oscillations, Solar Solar Cycle, Observations 

Notes

Acknowledgements

A.-M. Broomhall thanks the Institute of Advanced Study, University of Warwick for their support. V.M. Nakariakov: This work was supported by the European Research Council under the SeismoSun Research Project No. 321141, STFC consolidated grant ST/L000733/1, and the BK21 plus program through the National Research Foundation funded by the Ministry of Education of Korea. We thank the Birmingham Solar Oscillations Network, IZMIRAN Cosmic Ray Group, NOAA NGDC, OMNIWeb, and the Royal Observatory (Greenwich) for making their data freely available. We acknowledge use of NASA/GSFC’s Space Physics Data Facility’s OMNIWeb (or CDAWeb or ftp) service, and OMNI data. We acknowledge the Leverhulme Trust for funding the “Probing the Sun: inside and out” project upon which this research is based. The research leading to these results has received funding from the European Community’s Seventh Framework Programme ([FP7/2007 – 2013]) under grant agreement n° 312844 (see Article II.30. of the Grant Agreement).

Disclosure of Potential Conflicts of Interest

The authors declare that they have no conflicts of interest.

References

  1. Abramenko, V., Yurchyshyn, V., Linker, J., Mikić, Z., Luhmann, J., Lee, C.O.: 2010, Low-latitude coronal holes at the minimum of the 23rd Solar Cycle. Astrophys. J. 712, 813.  DOI. ADS. ADSCrossRefGoogle Scholar
  2. Antia, H.M., Basu, S., Hill, F., Howe, R., Komm, R.W., Schou, J.: 2001, Solar-cycle variation of the sound-speed asphericity from GONG and MDI data 1995 – 2000. Mon. Not. Roy. Astron. Soc. 327, 1029.  DOI. ADS. ADSCrossRefGoogle Scholar
  3. Basu, S., Antia, H.M.: 2010, Characteristics of solar meridional flows during Solar Cycle 23. Astrophys. J. 717, 488.  DOI. ADS. ADSCrossRefGoogle Scholar
  4. Basu, S., Broomhall, A.-M., Chaplin, W.J., Elsworth, Y.: 2012, Thinning of the Sun’s magnetic layer: the peculiar solar minimum could have been predicted. Astrophys. J. 758, 43.  DOI. ADS. ADSCrossRefGoogle Scholar
  5. Bazilevskaya, G.A., Krainev, M.B., Svirzhevskaya, A.K., Svirzhevsky, N.S.: 2013, Galactic cosmic rays and parameters of the interplanetary medium near solar activity minima. Cosm. Res. 51, 29.  DOI. ADS. ADSCrossRefGoogle Scholar
  6. Bazilevskaya, G., Broomhall, A.-M., Elsworth, Y., Nakariakov, V.M.: 2014, A combined analysis of the observational aspects of the quasi-biennial oscillation in solar magnetic activity. Space Sci. Rev. 186, 359.  DOI. ADS. ADSCrossRefGoogle Scholar
  7. Broomhall, A.-M., Chaplin, W.J., Elsworth, Y., Fletcher, S.T., New, R.: 2009, Is the current lack of solar activity only skin deep? Astrophys. J. Lett. 700, L162.  DOI. ADS. ADSCrossRefGoogle Scholar
  8. Chaplin, W.J., Elsworth, Y., Howe, R., Isaak, G.R., McLeod, C.P., Miller, B.A., van der Raay, H.B., Wheeler, S.J., New, R.: 1996, BiSON performance. Solar Phys. 168, 1.  DOI. ADS. ADSCrossRefGoogle Scholar
  9. Chaplin, W.J., Elsworth, Y., Isaak, G.R., Miller, B.A., New, R.: 2004, The solar cycle as seen by low-l p-mode frequencies: comparison with global and decomposed activity proxies. Mon. Not. Roy. Astron. Soc. 352, 1102.  DOI. ADS. ADSCrossRefGoogle Scholar
  10. Chaplin, W.J., Elsworth, Y., Miller, B.A., Verner, G.A., New, R.: 2007, Solar p-mode frequencies over three solar cycles. Astrophys. J. 659, 1749.  DOI. ADS. ADSCrossRefGoogle Scholar
  11. Clette, F., Lefèvre, L.: 2012, Are the sunspots really vanishing? Anomalies in solar cycle 23 and implications for long-term models and proxies. J. Space Weather Space Clim. 2(27), A6.  DOI. ADS. CrossRefGoogle Scholar
  12. Clette, F., Svalgaard, L., Vaquero, J.M., Cliver, E.W.: 2014, Revisiting the sunspot number. A 400-year perspective on the solar cycle. Space Sci. Rev. 186, 35.  DOI. ADS. ADSCrossRefGoogle Scholar
  13. Davies, G.R., Chaplin, W.J., Elsworth, Y., Hale, S.J.: 2014, BiSON data preparation: a correction for differential extinction and the weighted averaging of contemporaneous data. Mon. Not. Roy. Astron. Soc. 441, 3009.  DOI. ADS. ADSCrossRefGoogle Scholar
  14. Dziembowski, W.A., Goode, P.R.: 2005, Sources of oscillation frequency increase with rising solar activity. Astrophys. J. 625, 548.  DOI. ADS. ADSCrossRefGoogle Scholar
  15. Elsworth, Y., Howe, R., Isaak, G.R., McLeod, C.P., New, R.: 1990, Variation of low-order acoustic solar oscillations over the solar cycle. Nature 345, 322.  DOI. ADS. ADSCrossRefGoogle Scholar
  16. Fletcher, S.T., Chaplin, W.J., Elsworth, Y., New, R.: 2009, Efficient pseudo-global fitting for helioseismic data. Astrophys. J. 694, 144.  DOI. ADS. ADSCrossRefGoogle Scholar
  17. Hathaway, D.H.: 2010, The solar cycle. Living Rev. Solar Phys. 7, 1.  DOI. ADS. ADSCrossRefGoogle Scholar
  18. Hathaway, D.H., Rightmire, L.: 2010, Variations in the Sun’s meridional flow over a solar cycle. Science 327.  DOI. ADS.
  19. Howe, R., Komm, R., Hill, F.: 1999, Solar cycle changes in GONG P-mode frequencies, 1995 – 1998. Astrophys. J. 524, 1084.  DOI. ADS. ADSCrossRefGoogle Scholar
  20. Howe, R., Komm, R.W., Hill, F.: 2002, Localizing the solar cycle frequency shifts in global p-modes. Astrophys. J. 580, 1172.  DOI. ADS. ADSCrossRefGoogle Scholar
  21. Howe, R., Christensen-Dalsgaard, J., Hill, F., Komm, R., Larson, T.P., Rempel, M., Schou, J., Thompson, M.J.: 2013, The high-latitude branch of the solar torsional oscillation in the rising phase of Cycle 24. Astrophys. J. Lett. 767, L20.  DOI. ADS. ADSCrossRefGoogle Scholar
  22. Jain, K., Tripathy, S.C., Hill, F.: 2009, Solar activity phases and intermediate-degree mode frequencies. Astrophys. J. 695, 1567.  DOI. ADS. ADSCrossRefGoogle Scholar
  23. Jain, R., Roberts, B.: 1994, Solar cycle variations in p-modes and chromospheric magnetism. Solar Phys. 152, 261.  DOI. ADS. ADSCrossRefGoogle Scholar
  24. Jain, R., Tripathy, S.C., Watson, F.T., Fletcher, L., Jain, K., Hill, F.: 2012, Variation of solar oscillation frequencies in solar cycle 23 and their relation to sunspot area and number. Astron. Astrophys. 545, A73.  DOI. ADS. ADSCrossRefGoogle Scholar
  25. Javaraiah, J.: 2011, Long-term variations in the growth and decay rates of sunspot groups. Solar Phys. 270, 463.  DOI. ADS. ADSCrossRefGoogle Scholar
  26. Jimenez-Reyes, S.J., Regulo, C., Palle, P.L., Roca Cortes, T.: 1998, Solar activity cycle frequency shifts of low-degree p-modes. Astron. Astrophys. 329, 1119. ADS. ADSGoogle Scholar
  27. Kilcik, A., Yurchyshyn, V.B., Abramenko, V., Goode, P.R., Ozguc, A., Rozelot, J.P., Cao, W.: 2011, Time distributions of large and small sunspot groups over four solar cycles. Astrophys. J. 731, 30.  DOI. ADS. ADSCrossRefGoogle Scholar
  28. King, J.H., Papitashvili, N.E.: 2005, Solar wind spatial scales in and comparisons of hourly Wind and ACE plasma and magnetic field data. J. Geophys. Res. (Space Phys.) 110, 2104.  DOI. ADS. ADSCrossRefGoogle Scholar
  29. Lefèvre, L., Clette, F.: 2011, A global small sunspot deficit at the base of the index anomalies of solar cycle 23. Astron. Astrophys. 536, L11.  DOI. ADS. ADSCrossRefGoogle Scholar
  30. Libbrecht, K.G., Woodard, M.F.: 1990, Solar-cycle effects on solar oscillation frequencies. Nature 345, 779.  DOI. ADS. ADSCrossRefGoogle Scholar
  31. Livingston, W.: 2002, Sunspots observed to physically weaken in 2000 – 2001. Solar Phys. 207, 41.  DOI. ADS. ADSCrossRefGoogle Scholar
  32. Livingston, W., Penn, M.J., Svalgaard, L.: 2012, Decreasing sunspot magnetic fields explain unique 10.7 cm radio flux. Astrophys. J. Lett. 757, L8.  DOI. ADS. ADSCrossRefGoogle Scholar
  33. Mavromichalaki, H., Petropoulos, B., Plainaki, C., Dionatos, O., Zouganelis, I.: 2005, Coronal index as a solar activity index applied to space weather. Adv. Space Res. 35, 410.  DOI. ADS. ADSCrossRefGoogle Scholar
  34. Moreno-Insertis, F., Solanki, S.K.: 2000, Distribution of magnetic flux on the solar surface and low-degree p-modes. Mon. Not. Roy. Astron. Soc. 313, 411.  DOI. ADS. ADSCrossRefGoogle Scholar
  35. Nagovitsyn, Y.A., Pevtsov, A.A., Livingston, W.C.: 2012, On a possible explanation of the long-term decrease in sunspot field strength. Astrophys. J. Lett. 758, L20.  DOI. ADS. ADSCrossRefGoogle Scholar
  36. Nigam, R., Kosovichev, A.G.: 1998, Measuring the Sun’s eigenfrequencies from velocity and intensity helioseismic spectra: asymmetrical line profile-fitting formula. Astrophys. J. Lett. 505, L51.  DOI. ADS. ADSCrossRefGoogle Scholar
  37. Palle, P.L., Regulo, C., Roca Cortes, T.: 1989, Solar cycle induced variations of the low L solar acoustic spectrum. Astron. Astrophys. 224, 253. ADS. ADSGoogle Scholar
  38. Penn, M.J., Livingston, W.: 2006, Temporal changes in sunspot umbral magnetic fields and temperatures. Astrophys. J. Lett. 649, L45.  DOI. ADS. ADSCrossRefGoogle Scholar
  39. Penn, M.J., Livingston, W.: 2011, Long-term evolution of sunspot magnetic fields. In: Prasad Choudhary, D., Strassmeier, K.G. (eds.) IAU Symposium 273, 126.  DOI. ADS. Google Scholar
  40. Pevtsov, A.A., Nagovitsyn, Y.A., Tlatov, A.G., Rybak, A.L.: 2011, Long-term trends in sunspot magnetic fields. Astrophys. J. Lett. 742, L36.  DOI. ADS. ADSCrossRefGoogle Scholar
  41. Pevtsov, A.A., Bertello, L., Tlatov, A.G., Kilcik, A., Nagovitsyn, Y.A., Cliver, E.W.: 2014, Cyclic and long-term variation of sunspot magnetic fields. Solar Phys. 289, 593.  DOI. ADS. ADSCrossRefGoogle Scholar
  42. Rezaei, R., Beck, C., Schmidt, W.: 2012, Variation in sunspot properties between 1999 and 2011 as observed with the Tenerife Infrared Polarimeter. Astron. Astrophys. 541, A60.  DOI. ADS. ADSCrossRefGoogle Scholar
  43. Roberts, B., Campbell, W.R.: 1986, Magnetic field corrections to solar oscillation frequencies. Nature 323, 603.  DOI. ADS. ADSCrossRefGoogle Scholar
  44. Salabert, D., Garcia, R.A., Turck-Chieze, S.: 2015, Seismic sensitivity to sub-surface solar activity from 18 years of GOLF/SoHO observations. ArXiv e-prints. ADS.
  45. Tapping, K.F.: 1987, Recent solar radio astronomy at centimeter wavelengths – The temporal variability of the 10.7-cm flux. J. Geophys. Res. 92, 829.  DOI. ADS. ADSCrossRefGoogle Scholar
  46. Tlatov, A.G.: 2013, Long-term variations in sunspot characteristics. Geomagn. Aeron. 53, 953.  DOI. ADS. ADSCrossRefGoogle Scholar
  47. Tripathy, S.C., Kumar, B., Jain, K., Bhatnagar, A.: 2000, Observation of hysteresis between solar activity indicators and p-mode frequency shifts for Solar Cycle 22. J. Astrophys. Astron. 21, 357.  DOI. ADS. ADSCrossRefGoogle Scholar
  48. Tripathy, S.C., Kumar, B., Jain, K., Bhatnagar, A.: 2001, Analysis of hysteresis effect in p-mode frequency shifts and solar activity indices. Solar Phys. 200, 3.  DOI. ADS. ADSCrossRefGoogle Scholar
  49. Watson, F.T., Fletcher, L., Marshall, S.: 2011, Evolution of sunspot properties during solar cycle 23. Astron. Astrophys. 533, A14.  DOI. ADS. ADSCrossRefGoogle Scholar
  50. Watson, F.T., Penn, M.J., Livingston, W.: 2014, A multi-instrument analysis of sunspot umbrae. Astrophys. J. 787, 22.  DOI. ADS. ADSCrossRefGoogle Scholar
  51. Woodard, M.F., Noyes, R.W.: 1985, Change of solar oscillation eigenfrequencies with the solar cycle. Nature 318, 449. ADS. ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2015

Authors and Affiliations

  1. 1.Institute of Advanced StudiesUniversity of WarwickCoventryUK
  2. 2.Centre for Fusion, Space, and Astrophysics, Department of PhysicsUniversity of WarwickCoventryUK
  3. 3.School of Space ResearchKyung Hee UniversityYonginKorea
  4. 4.Central Astronomical Observatory at Pulkovo of RASSt PetersburgRussia

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