Solar And Stellar Activity Cycles

Synopsis

How Do You Predict The Parameters Of Future Solar Cycles And Estimate Their Terrestrial Effects? What Is The Role Of Dynamo Theory In The Cyclic Activity Of The Sun And Similar Stars? And What Are The Implications Of Chaos Theory For Stellar Cycles? This Book Offers A Unique Survey Of Our Knowledge Of Cyclic Activity For The Sun And Extends And Links This To Cycles In Other Stars. This Authoritative Reference Provides A Valuable Review Of Our Basic Knowledge Of The Sun, Of Solar Activity Cycles And Of Stellar Activity Cycles In General. It Shows The Importance Of Reliable Predictions Of Future Solar Cycles, And Carefully Explains The Methods Currently Used To Determine The Details Of These (with Special Reference To The Maximum Of Cycle 22). Some Of The Latest Research Into Solar Cycles Is Clearly Presented, Including Helioseismology, Observations Of The Extended Activity Cycle And The Polar Field Reversals And Theoretical Contributions From Dynamo Theory And Chaos Theory. For Graduate Students And Researchers, This Monograph Provides A Much-needed Synthesis Of Our Understanding Of Activity Cycles In The Sun And Other Stars. 1. Introduction. 1.1. The Significance Of Stellar Activity Cycles. 1.2. The Solar-stellar Connection. 1.3. The Solar Cycle And The Terrestrial Environment -- 2. Historical Survey. 2.1. The Discovery Of Sunspots. 2.2. The Maunder Minimum. 2.3. The Periodicity Law. 2.4. The Carrington Rotation And The Solar Flare. 2.5. The Zurich Sunspot Number. 2.6. Latitude Drift And The Butterfly Diagram. 2.7. The Wilson Effect. 2.8. Hale And The Mount Wilson Era. 2.9. The Magnetic Fields Of Sunspots. 2.10. The Magnetic Cycle. 2.11. The Polar Fields -- 3. The Structure Of The Sun And The Phenomena Of Activity. 3.1. Basic Data. 3.2. Radiative Transfer. 3.3. The Limb Darkening. 3.4. Departures From Spherical Symmetry. 3.5. The Chromosphere And The Corona. 3.6. The Chromospheric Structures. 3.7. Prominences. 3.8. Flares. 3.9. Coronal Structures. 3.10. Coronal Holes. 3.11. Active Longitudes -- 4. The Equations Of Magnetohydrodynamics And Magnetohydrostatics. 4.1. Maxwell's Equations And The Induction Equation. 4.2. The Fluid Equations. 4.3. The Equation Of State And The Energy Equation. 4.4. Structured Magnetic Fields. 4.5. Magnetic Buoyancy -- 5. The One-dimensional Configuration Of The Cycle. 5.2. The Maunder Minimum. 5.3. The Cycle Since 1700. 5.4. The Alternating Cycle. 5.5. The North-south Asymmetry. 5.6. The Luminosity Cycle. 5.7. The 'varves' Hypothesis -- 6. Heuristic Models Of The Solar Activity Cycle. 6.2. The Babcock Model. 6.3. Local Relaxation Models. 6.4. Preferential Poleward Migration. 6.5. The Flux Transport Model. 6.6. The Formation And Escape Of U-loops. 6.7. Forced Oscillator Models. 6.8. Dynamo Wave Models -- 7. Stellar Activity And Activity Cycles. 7.1. The Solar-stellar Connection. 7.2. Stellar Magnetic Fields. 7.3. Starspots. 7.4. Stellar Flares. 7.5. Activity Indicators. 7.6. Stellar Activity, Age, And Rotation. 7.7. Activity And Convection. 7.8. The Rossby Number. 7.9. Activity Variability In Individual Stars. 7.10. Characteristics Of Cyclically Varying Stars. 7.11. Grand Minima In Stars. 7.12. Photospheric Variability In Active Stars. 7.13. The Parameters Of Variability. 7.14. The Stellar Ageing Process. 7.15. Line Asymmetries In Stars -- 8. The Two-dimensional Representation Of The Extended Activity Cycle. 8.2. Other Indicators Of Activity. 8.3. The Onset Of Bipolar Activity. 8.4. The End Of Bipolar Activity. 8.5. The Poleward Branch -- 9. The Origin Of The Large-scale Fields. 9.2. Observing The Large-scale Magnetic Fields. 9.3. Solar Fields Near Sunspot Minimum Prior To Cycle 20. 9.4. The Polar Crown Gaps. 9.5. The Beginning Of Cycle 22. 9.7. The Beginning Of A New Cycle. 9.8. The Origin Of The Large-scale Fields. 9.9. Sources Of Organized Bipole Distributions. 9.10. Development Of A 'real' Unipolar Region. 9.11. Application To Observations -- 10. The Reversal Of The Polar Magnetic Fields. 10.1. The Polar Fields. 10.2. The Polar Crown And The Reversals. 10.3. The High-latitude Fields. 10.4. Simulations Of The Polar Fields. 10.6. Flux Histograms. 10.7. The Origins Of Regions A And C. 10.8. The Poleward Branches Of The Extended Activity Cycle. 10.9. The Coronal Holes And The Polar Reversals. 10.10. The Two-component Cycle -- 11. The Role Of Dynamo Theory In Cyclic Activity. 11.2. The Dynamo Equations. 11.3. Mean-field Electrodynamics. 11.4. The Migratory Dynamo. 11.5. Other Problems Of Solar Dynamo Theory. 11.6. Non-linear Dynamos. 11.7. Fast Dynamo Models. 11.8. The Small-scale Eddies -- 12. Helioseismology And The Solar Cycle. 12.2. The Iso-rotation Surfaces. 12.3. The Oscillations And The Observed Frequency-splittings. 12.4. The Interior Rotation Profile And The Theoretical Splittings. 12.5. Results. 12.6. Results Of Forward Calculations. 12.7. Comparison With Libbrecht's Data. 12.8. Shell Models For The Interior Rotation. 12.10. Cyclic Variability Of The Even Coefficients. 12.11. Cyclic Variability Of The Odd Coefficients -- 13. Cyclic Activity And Chaos. 13.2. Definition. 13.3. The Onset Of Chaotic Behaviour. 13.4. The Attractor. 13.5. The Strange Attractor. 13.6. Chaos And Dynamo Theory. 13.7. Is The Sunspot Cycle Chaotic? -- 14. Forecasting The Solar Cycle. 14.2. The Tactics And Strategies Of Forecasting. 14.3. Forecasts Based On Physical Models. 14.4. Precursors And Proxies. 14.5. Discussion -- The Sporting Journalist's Report. 14.6. Discussion -- With Hindsight. 14.7. The Role Of Coronal Holes. 14.8. Forecasting For Cycle 23 And Beyond -- 15. Summary And Conclusions. 15.2. The Input From Stellar Cycles. 15.3. Dynamo Models Of Cyclic Activity. 15.4. Chaos And Cyclic Activity. 15.5. Significant Features Of The Solar Cycle. 15.6. Precursors And Forecasts. Peter R. Wilson. Includes Index. Includes Bibliographical References And Indexes.