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www.iaus247.org. LOC contact: Cesar Mendoza-Briceno (Venezuela). SOC contact: Robertus Erd élyi (UK). Leakage of photospheric motions into the magnetic solar atmosphere…. R. Erdélyi B. De Pontieu, C. Malins, B. Pint é r, Y. Taroyan… robertus@sheffield.ac.uk

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  1. University of Sheffield

  2. www.iaus247.org LOC contact: Cesar Mendoza-Briceno (Venezuela) SOC contact: Robertus Erdélyi (UK) University of Sheffield

  3. Leakage of photospheric motions into the magnetic solar atmosphere… R. Erdélyi B. De Pontieu, C. Malins, B. Pintér, Y. Taroyan… robertus@sheffield.ac.uk SPARG, Department of Applied Mathematics, The University of Sheffield (UK) http://www.shef.ac.uk/~robertus University of Sheffield

  4. Introduction • Reminder of a basic fact: • Photosphere – chromosphere – TR (– corona are)magnetically coupled. • Manifestation of coupling has (at least) two exciting aspects: • Influence of magnetic atmosphere, e.g. magnetic carpet on oscillations. • Role of p modes in the dynamics of the solar atmosphere!(Less explored.) University of Sheffield

  5. Objects: atmospheric oscillations Oscillations ubiquitous in Sun • Solar atmosphere • More local oscillations • Sunspot oscillations, prominence oscillations, coronal loop oscillations, plume oscillations • One mode, many waveguides • Solar interior • Global oscillations • p, f, (g) modes • One waveguide, many modes University of Sheffield

  6. Coupling scales and elements Manifestations of presence in solar atmosphere: Organised flows (meridional; differential rotation, etc.) • Flow fields Random flows (granulation, convection, etc.) Coherent global fields (e.g. canopy) • Magnetic fields Random fields (magnetic carpet) University of Sheffield

  7. B(z) g x canopy (h) y z Simple-minded solar model corona chromospheric transitional layer (L) photosphere solar interior University of Sheffield

  8. Eigenmodes (L  0, B  0) University of Sheffield

  9. Eigenmodes (L  0, B  0) • Three-layer model • Polytropic interior • Magnetic transitional layer resonances damping • Isothermal magnetic upper atmosphere • Presence of Alfvén/slow continuum • Tirry et al. 1998, Pintér et al. 1999 University of Sheffield

  10. p8 l = 100 L = 2Mm Δν (μHz) p4 f p1 p2 p3 Imν (nHz) Bc (G) l = 100 L = 2Mm Bc (G) Eigenmodes (L  0, B  0) • Three-layer model • Polytropic interior • Magnetic transitional layer resonances damping • Isothermal magnetic upper atmosphere • Presence of Alfvén/slow continuum • Erdélyi and Pintér 2005 • Pintér et al. 2006 University of Sheffield

  11. Eigenmodes (L  0, B  0) Local magneto-seismology • Pintér, Erdélyi & Goossens 2006 University of Sheffield

  12. Lower atmospheric moss oscillation Wavelet analysis using Morlet wavelet (k=6) Oscillations usually suddenly start and stop. Not steady waves but wave trains of finite duration. Oscillations usually last for 32±7 mins or 3 to 7 cycles (just like p modes): rarely continue for more than 40 min. University of Sheffield

  13. p-mode driven spicules (and coronal oscillations) Vertical flux tube Inclined flux tube (50°) Chromospheric dynamics in inclined flux tubes are dominated by five minute periods because of significantly increased leakage of photospheric p modes into the atmosphere University of Sheffield

  14. P-mode driven spicules: 2-D University of Sheffield

  15. Summary • Numerous examples of waves and oscillations by SOHO and TRACE in the solar atmosphere structures • MHD theory seems to be a satisfactory description • Atmospheric seismology provides us information about: magnetic field, transport coefficients, fine structures, etc. • Coupling of photospheric motions (p modes, granules, etc.) to lower atmosphere (and above) • Stratification has significant effect • Lower atmosphere has back-reaction on global oscillations University of Sheffield

  16. The end University of Sheffield

  17. Solar Physics “Topical Issue” MHD Waves and Oscillations in Solar Magnetic Structures • Theory of MHD modes of magnetic structures • - Magnetic helioseismology and waves in sunspots • - MHD waves in the lower atmosphere • - Prominence oscillations • - Waves in the corona, MHD coronal seismology Deadline:12 January 2007 Editors: Robertus Erdélyi (robertus@sheffield.ac.uk) and John Leibacher (john.leibacher@gmail.com) University of Sheffield

  18. www.iaus247.org LOC contact: Cesar Mendoza-Briceno (Venezuela) SOC contact: Robertus Erdélyi (UK) University of Sheffield

  19. University of Sheffield

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