Modern status of the long-term variations in the galactic cosmic ray intensity

1. Modern status of the long-term variations in the galactic cosmic ray intensity M.B. Krainev1, G.A. Bazilevskaya1, S.K. Gerasimova2, P.A. Krivoshapkin2, G.F. Krymsky2, S.A. Starodubtsev2, Yu.I. Stozhkov1, N.S. Svirzhevsky1 1Lebedev Physical Institute, Russian Academy of Sciences, Moscow, Russia 2Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, Siberian branch of Russian Academy of Sciences, Yakutsk, Russia Outline: • Sunspot and magnetic cycles in the heliosphere and GCR intensity. What’s it all about? • Main observational features in the GCR intensity: the “normal” pair of solar cycles (1980-2000) • Theory and numerical modeling of the “normal” cycles in the GCR intensity • Semianalytical modeling (the base model by Krymsky et al., 2007-2012) • Anomaly of the 2000s - the unusual observational features

2. The sunspot and magnetic cycles on the Sun and in the GCR intensity ECRS-2012

3. Solar cycles in 1600-2010

4. The structure and characteristics of the heliosphere Baranev & Malama, 1993

5. Methods of CR observations ECRS-2012

6. Observations. GCRs near the Earth in 1980-2000: Form of time profiles, amplitude, crossover • A<0: pointed 7 GV < Rco < 13 GV • A>0: flat A<0 A>0 A<0 Krymsky et al.,2001 ECRS-2012

7. Observations. Time profiles of the GCR intensity at P10, V1,2 ECRS-2012

8. Observations. Radial profiles of the GCR intensity in the minima and maximum of the sunspot cycle ECRS-2012

9. Summary on the observations of the “normal” sunspot and magnetic cycles in the GCR intensity • The main features of the “normal” sunspot and magnetic cycles in the GCR intensity are known in the first approximation: • The GCR intensity varies generally in the opposite phase with the sunspot area • The form of the time profile and the maximum of the intensity are different for the opposite polarities of HMF. For q>0 : • the form is peaked (and J(αt)) for A<0 and flat (and J(Sss)) for A>0 • for R < Rco: Jmax (A<0) < Jmax (A>0) and quite the reverse for R>Rco • the crossover rigidity from the balloon and NM data: 7< Rco [GV]<13 • The radial gradient of the intensity in the intermediate and outer heliosphere Gr(A<0) > Gr (A>0) • The detailed observations of the GCR intensity time and latitude profiles are carried out only in the inner heliosphere, rather special region. ECRS-2012

10. Theory and modeling. 1. Boundary-value problem. Boundary-value problem (steady-state, 2D) for U=J/p2 Jokipii & Wibberenz, 1998 ECRS-2012

11. Theory and numerical modeling. 2. General TPE coefficients. ECRS-2012

12. Theory and numerical modeling. 2. General TPE coefficients. ECRS-2012

13. Specific numerical models. Drifts Dominating in the low-latitude heliosphere. Kalinin, Krainev,Poster SH 347 ECRS-2012

14. Description of J(r,θ,T,t) in the “normal” solar cycles for Drifts Dominating in the low-latitude heliosphere Krainev, Kalinin,Poster SH 346 ECRS-2012

15. Specific numerical models. “Compound” model by the Potchefstroom group. Ferreira & Potgieter (2001, 2004) ECRS-2012

16. Summary on the efforts to numerically model the “normal” sunspot and magnetic cycles • The detailed models have been developed that describe the main observed long-term GCR intensity variations • However, to achieve this aim : • the known properties of the high-latitude heliospheric magnetic field and field-particle interaction are strongly changed (divB≠0, parallel diffusion coefficient strongly depends on the polarity, enhanced latitudinal diffusion); • the time behavior of the heliospheric characteristics in different parts of the heliosphere is the same as near the Earth (very specific region of the heliosphere). • The meaning of the main features in the “normal” sunspot and magnetic cycles depends on which way (drift or diffusion domination) is used for modeling. ECRS-2012

17. Theory and semianalytical modeling. The base model by Yakutsk group Krymsky et al. (2007-2012) ECRS-2012

18. Description of J(t) in the “normal” solar cycles using the “Base” model ECRS-2012

19. Anomaly of the 2000s. 1. Amplitudes of low vs high energies ECRS-2012

20. Anomaly of the 2000s. 2. Details of time profiles of low vs high energies Bazilevskaya et al., 2012see also Bazilevskaya et al., Poster SH 579 ECRS-2012

21. Anomaly of the 2000s. 3. GCR vs ACR ECRS-2012

22. Conclusions • The main features of the “normal” sunspot and magnetic cycles in the GCR intensity are known in the first approximation although the time profiles are studied only near the Earth in the inner low-latitude heliosphere, rather special region. • The detailed models have been developed that describe the main observed long-term GCR intensity variations, although to achieve this aim the properties of the high-latitude heliospheric magnetic field and field-particle interaction should be rather unusual and the time behavior of the heliospheric characteristics in different parts of the heliosphere should follow that near the Earth. • In these circumstances the other ways to model and understand the “normal” sunspot and magnetic cycles in the GCR intensity could be explored (such as the base model of the Yakutsk group). • The anomalous behavior of the GCRs and ACRs in the 2000s poses the new challenge for understanding the sunspot and magnetic cycles in their intensity. THANK YOU! ECRS-2012