Interplanetary magnetic field and relativistic solar particle events

1. Interplanetary magnetic field and relativistic solar particle events S. Masson1, S. Dasso2, P. Démoulin1 and K.-L. Klein1 1 LESIA - Observatoire de Paris 2 IAFE - Universitad de Buenos Aires Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

2. How can we constrain acceleration of relativistic protons ? Earth  Multi wavelengths analysis Beams of non-thermal electrons : radio emission X-rays and -rays: Impact Relativistic protons Parker spiral Synchrotron emission: relativistic e-. GLE measurements Shock waves: radio emission From Earth measurements, go back to Sun across the Parker spiral (1.2 AU)  Constrain the acceleration regions of relativistic particles Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

3. The timing and connection problem  Delay between the arrival time of the first relativistic protons at the Earth (=ground level enhancement or GLE) and various electromagnetic signatures of particle acceleration. Carmichael (1972), Kodama et al. (1977), Cliver et al. (1982), Kahler et al. (2003) Parker spiral connection  Active regions associated to GLEs not always Earth-connected by the Parker spiral. Cliver et al. (1982), Stoker (1994), Gopalswamy (2005) Why is there a systematic delay, and what determines the magnetic connection ? www.nmdb.eu Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

4. The timing and connection problem  How to explain the delay and the connection problem - Acceleration by the CME’s shock high in the corona - Delayed acceleration of energetic particles during the flare - Particle diffusion during the interplanetary transport Kahler (1994), Cliver et al (2004), Reames (2009) Klein et al. (1999), Li et al. (2009) Wibberenz & Cane (2006), Cane (2003), Richardson et al. (1991)  based on the propagation of particles along the Parker spiral Should we always consider the Parker spiral as the real connection between the acceleration site and Earth ? Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

5. Detailed temporal analysis  GLE on 20 January 2005 Common release of radio emitting electron beams and relativistic protons Most energetic protons > 300 MeV and electrons are accelerated during the second episode 06:45:30 UT Injection time at 06:46 UT A longer interplanetary path length Masson et al. (2009) Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

6. The interplanetary magnetic field (IMF) Interplanetary magnetic field lines emission particles Earth Earth  Sun-Earth connections and IP path length Interplanetary coronal mass ejection or magnetic cloud D > 1.2 UA Parker spiral D ~ 1.2 AU  Which IMF for particle propagation ? Measurements of the magnetic field and plasma parameters Magnetic structure of the IP space Length travelled by energetic particles Injection time of energetic particles In-situ particles measurements (Velocity dispersion analysis) Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

7. Magnetic structure of IMF during GLE GLE B ~ 6 nT Parker spiral (quiet IMF) • - B non coherent, Bmag~ 5 nT • T exp~ Tobs~ 2.105 K • p~ 1  ~ 0° (Lopez & Freeman, 1986; Elliot et al., 2005)  ~ - 45° Texp Tobs Propagation along the Parker spiral in a quiescent solar wind p~ 1 Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

8. Magnetic structure of IMF during GLE GLE Back Interplanetary coronal mass ejection ICME • Increase of Bmag , high coherent Bmag • - T exp> 2 Tobs • - p < 1 ( Liu et al., 2005; Ebert et al., 2009) discontinuity of B components:  B partially reconnected with the SW Texp> 2 Tobs Backof ICME or MC (Dasso et al., 2006, 2007)  < 1 Propagation of particles in the back For the last 10 GLEs of the 23rd solar cycle Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

9. Interplanetary length and solar release time  Velocity dispersion analysis 26 December 2001: Energetic protons (12-40 MeV) SoHO/ERNE  Assuming that all particles are injected simultaneously: (www.srl.utu.fi/erne_data/) Interplanetary length Solar release time Relativistic protons (4 GeV) Neutron monitor Performing on 7 events (missing data) (Moraal et al., 2009) Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

10. Interplanetary length versus magnetic structure Consistent results between path length and interplanetary magnetic structure (7 GLEs) 28 /10 /03: relativistic particles travel ~ 2 AU (Miroshnichenko et al., 2005) 2006 December 13: Interplanetary structure like Parker spiral and a travelled length of 2 AU (bad determination ?? shock acceleration ???) Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

11. Solar release time versus electron type III injection Timing comparison of the injection time of protons at the Sun and the interval during which electrons are injected and produce type III burst (ttypeIII background + 3) event Protonsare injected during electron injection Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010

12. Conclusion  Results From two independent studies: - magnetic structure of the IMF - velocity dispersion analysis (travelled length)  consistent results for interplanetary length and the injection time  What is new for the understanding of solar relativistic particles?  Interplanetary geometry plays a crucial role in the timingproblem.  An essential constraint to associate the solar phenomena to particles acceleration • What is the effects of the magnetic structure on the particle transport ? • Development of model to compute the MC / ICME lengths • Detailed analysis of some events, taking into account the IMF structure (Kahler, Krucker & Szabo, 2010) Interplanetary magnetic field and relativistic solar particle events S. Masson - 10th RHESSI Workshop - Annapolis - August 2010