Kaz. Munakata 1 , C. Kato 1 , S. Yasue 1 , J. W. Bieber 2 , P. Evenson 2 , T. Kuwabara 2 ,

1. Muon Detector Workshop (17 October, 2011@La Petite Rouge) GlobalMuonDetectorNetwork (GMDN) Kaz. Munakata1, C. Kato1, S. Yasue1, J. W. Bieber2, P. Evenson 2, T. Kuwabara 2, M. R. DaSilva 3, A. Dal Lago 3, N. J. Schuch 4, M. Tokumaru 5, M. L. Duldig 6, J. E. Humble 6, I. Sabbah 7,8, H. K. Al Jassar 9, M. M. Sharma 9 GMDN collaboration 1 Shinshu University, JAPAN 2 Bartol Research Institute, USA 3 INPE, BRAZIL 4 CRS/INPE, BRAZIL 5 STE Laboratory, JAPAN 6 University of Tasmania, AUSTRALIA 7 College of Health Science, KUWAIT 8 Alexandria University, EGYPT 9 Kuwait University, KUWAIT 15 people from 9 institutes in 6 countries working with 4 muon detectors in operation at… Nagoya,Hobart,São Martinho,Kuwait (36 m2)(16 m2)(28 m2)(9 m2)

2. Ground-based detectorsuse atmosphere as an active component • Ground-based detectors measure byproducts of the interaction of primary Galactic Cosmic Rays (GCRs: predominantly protons and helium nuclei) with Earth’s atmosphere. • Two types of observation: • Neutron Monitors Typical energy of primary: ~1 GeV for solar CRs (GLEs), ~10 GeVfor GCRs ommidirectional • Muon Detectors Typical energy of primary: ~50 GeVfor GCRs (surface muon detector) multi-directional

3. Energy responses of NM and GMDN to primary GCRs Differential response fn. (solar min.) Integral response fn. (solar min.) 14.5 59.4 Rigidity of primary GCRs (GV)

4. Viewing directions in the Global Muon Detector Network (GMDN) • ☆indicates the location of the detector. • ○□△display the asymptotic viewing directions of median energy cosmic rays corrected for the geomagnetic bending. • Thin lines indicate the spread of viewing direction for the central 80 % of the energy response to primary CRs.

5. Deriving anisotropy vector : pressure corrected count rate in the j th directional channel of the i th detector We derive which minimize ….

6. 2D map analysis Nagoya,Hobart,São Martinho Kuwait   Four horizontal layers of Proportional Counter tubes 1 hour data (2006 12/14 09:30UT) • Useful when analyzing local-structure like the “loss-cone”. • Applied to the GMDN data (Fushishita et al., ApJ, 715, 2010). N Pitch angle from the sunward nominal IMF S W E

7. GCR transport equation (Parker 1965) : GCR density (omnidirectional intensity) SW convection diffusion Adiabatic cooling : streaming : anisotropy • Anisotropy () tells us the spatial gradient ( ) • which reflects the magnetic field geometry

8. What the anisotropy tells us? • GCR density decrease (Forbush Decrease). • Strong GCR streaming (wind) is associated. • Need to measure density & streaming separately. • Only global network can make such a precise measurement . (%) Muon count rates in 3 vertical telescopes 2001 Can deduce 3D distribution from the GCR gradient (G) from the anisotropy G Detector orbit GCR depleted region Single telescope tells us only 1D distribution along the orbit

9. What does GMDN tell us? http://neutronm.bartol.udel.edu/

10. Testing the drift model A > 0 A < 0 Away Toward Drift model prediction by Kota and Jokipii (1983) Toward Away 7.5 excursion of the Earth may cause the seasonal variation in the gradient.

11. FD & CME on Oct. 29, 2003 ICME doy CR density CR anisotropy

12. GCRs in the Magnetic Flux Rope • GCR depleted region is formed in an expanding MFR into which GCRs can penetrate only through the cross-filed diffusion. • GCR density gradient G pointing away from the MFR can be deduced from the diamagnetic drift streaming. • We deduce MFR geometry from the GCR density gradient by assuming an infinite straight cylinder. GCR depleted region (Forbush decrease) G  G(t)

13. CRs 2R(t) Cross-field diffusion Adiabatic cooling CR diffusion into MFR CRs can penetrate into MFR only by the cross-field diffusion k can be evaluated from CR data during MFR Self-similar expansion of MFR Dimensionless parameter k0 determines k

14. Numerical solutions • k0 appropriate to the observed • FD is 10 ~ 50. • f (x) rapidly becomes stationary, much earlier than the 1st contact of Earth with MFR at t=1.

15. Stationary solution f(x) is given by a polynomial expression…. Use polynomial f(x)（n≦6） for best-fitting to the data

16. Best-fitting to the data(with MFR geometry) Best-fitting at k0=18 k = k0v0R0 = 1.61021 (cm2/s) (v0=0.21 AU/day, R0=0.17 AU) k// ~ 3.01023 (cm2/s) for muon (Munakata et al., 2002)  k/ k ~ 0.005 for muon

17. Z Y X Z Y X cosmic ray ACE B&V IPS STEL SMEI (Tokumaru et al., 2006) (Kuwabara et al., 2007)

18. Cosmic ray precursors Loss cone (deficit) Magnetic flux rope CR cylinder Shock reflection (excess) Munakata et al. (JGR, 105, 2000) Leerungnavarat et al. (ApJ, 593, 2003) • CRs behind the shock travel to the upstream Earth with the speed of light overtaking the shock ahead. • The precursor is seen as the deficit intensity of CRs arriving from the sunward IMF. • loss-cone (LC) precursor • CRs reflected and accelerated by the approaching shock are also observed as an excess intensity. • precursory excess (sunward) distance from the shock (mfp) pitch angle cosine (anti-sunward) Sunward IMF direction

19. X3.4 flare onset 02:38UT on 12/13 CME event in December 2006 VSW ~3% FD @~30 GeV Flare onset SSC B CME ejecta Kp No additional disturbances GMDN: CR density average VSW = 1160 km/s 12/13 12/14 12/15 12/16 12/17 GSE-x GSE-y GSE-z Liu et al., ApJ 689, 2008