Helioseismic Diagnostics of Solar Convection and Activity

ISBN-13: 9780792365204 / Angielski / Twarda / 2000 / 578 str.

Zdenek Svestka; Zdenek Svestka; John W. Harvey

Opis

Most papers in this book were presented at the SOHO-9 Workshop 'Helioseismic Diagnostics of Solar Convection and Activity', held on 12-15 July 1999 at Stanford University, California, U.S.A. Some papers which were not presented at the work shop have been added, after authors had been invited in Solar News to contribute to this book. All papers submitted to this book have been refereed, and only those of high scientific quality were accepted for publication. The book focuses on the recent advances in our understanding of solar con vection and activity, and on methods and results of helioseismic diagnostics of the internal structures and dynamics of solar convection and active regions. The methods of local helioseismology (time-distance tomography, ring-diagram analy sis, acoustic imaging and holography), intensively developed in the past few years, have provided promising results on the deep structure of large-scale convection and flows, emerging active regions, and sunspots. Along with the traditional 'global' helioseismology based on frequencies of resonant oscillation modes, the local-area techniques have become increasingly important for studying the solar interior and the mechanisms of solar activity. The new high-resolution helioseismology projects 'Solar Oscillation Investiga tionlMichelson Doppler Imager' (SOIlMDI) on board SOHO, and ground-based 'Global Oscillation Network Group' (GONG) have provided a tremendous amount of solar oscillation data. Extracting from these data the information about the in ternal properties and dynamics of the Sun, and using this information in theoretical models and space weather forecasts are new challenges in solar physics."

Spis treści

Preface. I: Theories of Solar Convection, Rotation, and Activity. Towards Understanding Solar Convection and Activity; D. Gough. Fluid Dynamics and MHD of the Solar Convection Zone and Tachocline: Current Understanding and Unsolved Problems; P.A. Gilman. Can We Get the Bottom B? A. Ruzmaikin. The Coupling of Solar Convection and Rotation; M.S. Miesch. Realistic Solar Convection Simulations; R.F. Stein, Å. Nordlund. Solar Magnetoconvection; N.E. Hurlburt, et al. The Solar Dynamo and Emerging Flux; G.H. Fisher, et al. On the Twist of Emerging Flux Loops in the Solar Convection Zone; Y. Fan, D. Gong. II: Helioseismic Tomography. Time-Distance Inversion Methods and Results; A.G. Kosovichev, et al. Time-Distance Helioseismology with f Modes as a Method for Measurement of Near-Surface Flows; T.S. Duvall Jr., L. Gizon. Travel Time Sensitivity Kernels; A.C. Birch, A.G. Kosovichev. Calculation of the Sun's Acoustic Impulse Response by Multi-Dimensional Spectral Factorization; J.E. Rickett, J.F. Claerbout. Ray Travel Time and Distance for the Planar Polytrope; G.H. Price. Sensitivity Kernels for Time-Distance Inversion; J.M. Jensen, et al. III: Acoustic Imaging and Holography. Acoustic Imaging of Solar Active Regions; D.-Y. Chou. Basic Principles of Solar Acoustic Holography; C. Lindsey, D.C. Braun. Helioseismic Holography of Active-Region Subphotospheres; D.C. Braun, C. Lindsey. Phase-Sensitive Holography of Solar Activity; D.C. Braun, C. Lindsey. Stochastic Seismic Emission from Acoustic Glories and the Quiet Sun; A.-C. Donea, et al. IV: Ring-Diagram Analysis. Solar Shear Flow Deduced from Helioseismic Dense-Pack Samplings of RingDiagrams; D.A. Haber, et al. Near-Surface Flow Fields Deduced Using Correlation Tracking and Time-Distance Analyses; M. de Rosa, et al. Local Fractional Frequency Shifts Used as Tracers of Magnetic Activity; B. Hindman, et al. V: Magnetic Fields and Oscillations. Sunspot Oscillations: A Review; T.J. Bogdan. Modelling p-Mode Interaction with a Spreading Sunspot Field; P.S. Cally. Measuring Magnetic Oscillations in the Solar Photosphere: Coordinated Observations with MDI, ASP and MWO; A.A. Norton, R.K. Ulrich. Interaction between Network and Intranetwork Magnetic Fields; J. Zhang, et al. VI: Solar-Cycle Variations of the Internal Structure and Rotation. Variations in Solar Sub-Surface Rotation from Gong. Data 1995-1998; R. Howe, et al. Time Variability of Rotation in Solar Convection Zone from SOI-MDI; J. Toomre, et al. Possible Solar Cycle Variations in the Convection Zone; S. Basu, H.M. Antia. Solar Cycle Variation in Solar f-Mode Frequencies and Radius; H.M. Antia, et al. Solar Cycle Variations of Large-Scale Flows in the Sun; S. Basu, H.M. Antia. Does the Tachocline Show Solar Cycle Related Changes? S. Basu, J. Schou. Empirical Estimate of p-Mode Frequency Shift for Solar Cycle 23; K. Jain, et al.