изменения спиральности в солнечном цикле

1. изменения спиральности в солнечном цикле Kirill Kuzanyan IZMIRAN, Russian Academy of Sciences, Moscow region, Russia

2. Questions: Can we learn more of solar activity looking at magnetic helicity? • Magnetic helicity is important for closure-up of self-contained dynamo action • Was there anything peculiar about cycle 23 compared to other cycles? • Are we approaching another “global” Maunder-like minimum?

3. Dynamo model with evolution of Helicity Magnetic field generation (Parker Dynamo) Generation of Helicity Parameterized equation

4. The Butterfly Diagramproxies of magnetic field(A,B)

5. 20 years systematic monitoring of the solar vector magnetic fields in active regions taken at Huairou Solar observing station, China (1987-2006) More observations from Mitaka (Japan) and also Mees, MSFC (USA) etc., but only Huairou data systematically cover 20 years period.

6. observations Observable !

7. AR 10930: HC over the filtergram; positive/negative: a typical AR. The filtergram of AR 10930; contours of current helicity HC for positive (negative) values shown in red (green), corresponding to absolute values of 0.2, 0.5, 1.0, 4.0 G2/m, respectively. The field of view is 104''80''.

8. Helicity overlaid with butterfly diagram

9. Force free factor overlaid with butterfly diagram

10. Compare: Qualitatively, the both quantities are distributed in a similar manner. So, despite the noisy nature of the data, accuracy of measurements is reliable.

11. Dynamo models help…? • in prediction of the solar cycle!? • The model which we considered in 1990s was far too simple! Recall the results 1997-2000

12. Nonliear Parker’s Dynamo in inhomogeneous media

13. поле в единицах энергии равнораспределения

14. Зависимость амплитуды цикла от длительности фазы роста(Dmitrieva, Kuzanyan, Obridko, 2000)

15. Предсказание амплитуды цикла по динамике его ветви роста прогноз 100-114 цикл 23: 121

16. Simple self-consistent dynamo model with evolution of helicity (dynamical nonlinear dynamo) Kleeorin, Kuzanyan, Moss, Sokoloff, Rogazhevsky, Zhang, A&A, 2003; and a series of publications of the authors in 2005-2009

18. Choice of Parameter Range (Example) C=0.01- ok! HELICITY C=0.1 too high value LATITUDE

19. Kleeorin et al. 2003EVOLUTION OF HELICITY WITH TIME(Northern HemisphereN) S N HELICITY Sunspot Group Number Magnetic Energy ~1988 ~1997 Diffusion Time Units

20. The methods of prediction? 1. Use data themselves: • The time series is too short for reliable prediction • The noise level is too high -- neural networks (training on previous cycles) -- data assimilation -- time series in analysis of dynamical systems Very little knowledge of physics is involved but mainly mathematical assumptions

21. Example: Singular Spectral Analysis (SSA) • after Loskutov, Istomin, Kotlyarov, Kuzanyan (Astron. Rep. 2001): amplitude prediction up to 18 yr

22. Summary • Helicity helps in development of self-consistent dynamo models • Despite vast inconsistency between the models we still may try to estimate the forthcoming activity • The two forthcoming cycles 24 and 25 will likely be relatively low compared to those over the recent centuries (sign of a Minimum?!)

23. Thank you!

24. The methods of prediction? 1. Use data themselves: • The time series is too short for reliable prediction • The noise level is too high -- neural networks (training on previous cycles) -- data assimilation -- time series in analysis of dynamical systems Very little knowledge of physics is involved but mainly mathematical assumptions

25. Example 1: Data Assimilation method prediction of the solar cycle 24 published by Kitiashvili & Kosovichev 2008

26. Example 2: Singular Spectral Analysis (SSA) • after Loskutov et al. 2001 (up to 18 yr)

27. Obridko and Shelting 2009

28. Different forecasts for cycle24 (incl. precursor methods) Neither worse but nor better than the other methods!

29. Summary • No absolutely effective methods of prediction are developed so far • Despite vast inconsistency between the models we still may try to estimate the forthcoming activity • The two forthcoming cycles 24 and 25 will likely be relatively low compared to those over the recent centuries (sign of a Minimum?!)

30. Summary • No absolutely effective methods of prediction are developed so far • Despite vast inconsistency between the models we still may try to estimate the forthcoming activity • The two forthcoming cycles 24 and 25 will likely be relatively low compared to those over the recent centuries (sign of a Minimum?!)

31. Appendix Supplementary material

32. Anti-Correlation between the solar activity and cosmic rays Comparison of the total open flux BE derived from photospheric field measurements with the radial IMF strength ¦ Bx¦ recorded at Earth. Here MWO datawere used for 1967–1976 and 1995–2000, while WSO data were used for the remaining intervals. Also plotted is the sunspot number RI (after Wang Y-M et al., 2006).

33. Anti-Correlation between the solar activity and cosmic rays Temporal changes of CR intensity (% to 1976), flare index Fx, sunspot numbers W, average values of solar magnetic field strength – index Bss and partial indexes ZO, ZE, SO, and SE (mkT).

34. Anti-Correlation between the solar activity and cosmic rays Temporal changes of CR intensity (% to 1976), flare index Fx, sunspot numbers W, average values of solar magnetic field strength – index Bss and partial indexes ZO, ZE, SO, and SE (mkT).