Foreword .................................................... xv
E.N. Parker
1 Dynamic Sun: an introduction ................................. 1
B.N. Dwivedi
1.1 Introduction ............................................ 1
1.2 Main contents ........................................... 2
1.3 Concluding remarks ...................................... 7
2 Solar models: structure, neutrinos and helioseismological
properties ................................................... 8
J.N. Bahcall, S. Basu and M.H. Pinsormeault
2.1 Introduction ............................................ 8
2.2 Standard solar model .................................... 9
2.3 Variant and deviant solar models ....................... 11
2.4 Neutrino physics ....................................... 14
2.4.1 Standard model .................................. 16
2.4.2 Calculated uncertainties ........................ 18
2.4.3 NACRE charged particle fusion rates ............. 20
2.4.4 Variant and deviant models ...................... 21
2.4.5 The electron number density ..................... 21
2.5 Sound speeds ........................................... 24
2.6 Discussion and summary ................................. 29
2.6.1 Standard solar model: current epoch ............. 29
2.6.2 Neutrino fluxes and related quantities .......... 29
2.6.3 Sound speeds .................................... 31
References .................................................. 32
3 Seismic Sun ................................................. 36
S.M. Chitre and H.M. Aitia
3.1 Introduction ........................................... 36
3.2 Structure equations and the Standard Solar Model ....... 37
3.3 Seismology of the Sun .................................. 39
3.4 Inferences about the solar structure ................... 41
References .................................................. 52
4 Rotation of the solar interior .............................. 55
J. Christensen-Dalsgaard and M.J. Thompson
4.1 Introduction ........................................... 55
4.2 Helioseismic probes of the solar interior .............. 57
4.2.1 Rotational effects on the oscillation
frequencies ..................................... 59
4.2.2 Data on rotational splitting .................... 60
4.2.3 Inversion for solar internal rotation ........... 63
4.3 The solar internal rotation ............................ 64
4.3.1 Rotation of the solar convection zone ........... 66
4.3.2 The tachocline .................................. 68
4.3.3 The radiative interior .......................... 70
4.4 Modelling solar rotation ............................... 71
4.5 Final remarks .......................................... 73
References .................................................. 74
5 Helioseismic tomography ..................................... 78
A.G. Kosovichev
5.1 Introduction ........................................... 78
5.2 Method of helioseismic tomography ...................... 79
5.3 The ray approximation .................................. 84
5.4 The Born approximation ................................. 85
5.5 Inversion methods ...................................... 87
5.6 Diagnostics of supergranulation ........................ 88
5.7 Large-scale flows ...................................... 90
5.8 Meridional circulation ................................. 91
5.9 Emerging active regions ................................ 91
5.10 Structure and dynamics of sunspots ..................... 93
Imaging the far side of the Sun ............................. 97
Conclusion .................................................. 99
References ................................................. 100
6 The solar dynamo as a model of the solar cycle ............. 103
A.R. Choudhuri
6.1 Introduction .......................................... 103
6.2 Relevant observations ................................. 104
6.3 Some basic MHD considerations ......................... 108
6.4 The turbulent dynamo and mean field MHD ............... 110
6.5 Dynamo in the overshoot layer? ........................ 114
6.6 The Babcock-Leighton approach and advective dynamo
models ................................................ 117
6.7 Miscellaneous ill-understood issues ................... 121
6.8 Conclusion ............................................ 123
References ................................................. 124
7 Spectro-polarimetry ........................................ 128
J.O. Stenflo
7.1 Remote sensing of the Sun's magnetic field: an
introduction .......................................... 128
7.2 Observational techniques and their limitations ........ 130
7.3 Zeeman-effect diagnostics ............................. 133
7.4 The Hanle effect ...................................... 138
7.5 Optical pumping ....................................... 142
7.6 Concluding remarks .................................... 146
References ................................................. 146
8 Solar photosphere and convection ........................... 148
Å. Nordlund
8.1 Introduction .......................................... 148
8.2 Dynamic and thermal properties of the solar
photosphere ........................................... 150
8.3 Spectral line synthesis ............................... 152
8.4 P-mode diagnostics .................................... 156
8.5 Large scale velocity fields ........................... 159
8.6 Consequences for coronal and chromospheric heating .... 162
8.7 Concluding remarks .................................... 162
References ................................................. 163
9 The dynamics of the quiet solar chromosphere ............... 165
W. Kalkofen, S.S. Hasan and P. Ulmschneider
9.1 Introduction .......................................... 165
9.2 Oscillations in the nonmagnetic chromosphere .......... 166
9.3 Oscillations in the magnetic network .................. 172
References ................................................. 178
10 Heating of the solar chromosphere .......................... 181
P. Ulmschneider and W. Kalkofen
10.1 Introduction .......................................... 181
10.2 Empirical chromosphere models ......................... 182
10.3 Energy balance and the necessity of mechanical
heating ............................................... 184
10.4 Overview of the heating mechanisms .................... 187
10.5 Search for the important heating mechanisms ........... 188
10.6 Summary and outlook ................................... 193
References ................................................. 195
11 The solar transition region ................................ 196
O. Kjeldseth-Moe
11.1 Introduction .......................................... 196
11.2 Emission from the transition region plasma ............ 197
11.2.1 The emitted intensity .......................... 197
11.2.2 Underlying approximations and concepts ......... 198
11.3 Constant conductive flux and the thin transition
region ................................................ 200
11.4 The extended transition region ........................ 201
11.4.1 Excess emission at temperatures below 105 К .... 201
11.4.2 The EUV flash spectrum: direct observation of
an inhomogeneous transition region ............. 202
11.4.3 A transition region structured by the
magnetic field ................................. 202
11 4.4 Spicules and the transition region ............. 202
11.4.5 An extremely fine structured transition
region? ........................................ 203
11.4.6 Unresolved fine structures ..................... 204
11.4.7 Unresolved dynamic evolution? .................. 205
11.5 The redshifted transition region ...................... 205
11.5.1 Line shifts in the transition region ........... 205
11.5.2 Red- or blueshifts from siphon flows and
spicules? ...................................... 206
11.5.3 Red shifts as signatures of downward
propagating waves .............................. 207
11.6 The dynamic and time dependent transition region ...... 208
11.6.1 Morphology of transition region loops .......... 208
11.6.2 Velocities in transition region loops .......... 209
11.6.3 Rapid time changes in the emission ............. 210
11.7 Conclusion - a new concept for the transition
region ................................................ 212
References ................................................. 214
12 Solar Magnetohydrodynamics ................................. 217
E.R. Priest
12.1 Introduction .......................................... 217
12.2 Magnetohydrodynamic equations ......................... 219
12.2.1 Flux tubes ..................................... 219
12.2.2 Basic equations ................................ 219
12.2.3 Induction equation ............................. 220
12.2.4 The Lorentz force .............................. 223
12.3 Magnetohydrostatics ................................... 224
12.3.1 Introduction ................................... 224
12.3.2 Potential fields ............................... 225
12.3.3 Force-free fields .............................. 226
12.3.4 Magnetic flux tubes ............................ 228
12.4 Magnetohydrodynamic waves ............................. 229
12.4.1 Soundwaves ..................................... 229
12.4.2 Alfven waves ................................... 231
12.4.3 Compressional Alfven waves ..................... 232
12.4.4 Magnetoacoustic waves .......................... 233
12.4.5 Shockwaves ..................................... 233
12.5 Concluding comment .................................... 237
References ................................................. 237
13 Solar activity ............................................. 238
Z. Švestka
13.1 Solar cycles .......................................... 238
13.2 Active regions ........................................ 240
13.3 Complexes of activity and interconnecting loops ....... 243
13.4 Surges, jets, and sprays .............................. 244
13.5 Solar flares .......................................... 245
13.6 Coronal mass ejections and coronal storms ............. 249
13.7 Relation between CMEs and flares ...................... 252
13.8 Other sources of CMEs ................................. 255
13.9 Causes of instabilities ............................... 255
13.10 Accelerated particles ................................ 256
13.11 Impacts of solar activity at the Earth ............... 257
References ................................................. 259
14 Particle acceleration ...................................... 262
A.G. Emslie and J.A. Miller
14.1 Introduction .......................................... 262
14.2 Observational constraints ............................. 263
14.2.1 Electrons ...................................... 264
14.2.2 Ions ........................................... 266
14.3 Direct electric field acceleration .................... 266
14.4 Stochastic acceleration ............................... 271
14.4.1 The cascading turbulence model ................. 276
14.4.2 Baseline case .................................. 278
14.5 Conclusions ........................................... 285
References ................................................. 285
15 Radio observations of explosive energy releases on the
Sun ........................................................ 288
M.R. Kundu and S.M. White
15.1 Introduction .......................................... 288
15.2 Flare studies ......................................... 289
15.2.1 Millimeter flare emission: comparison with
microwave and hard X-rays/gamma rays ........... 289
15.2.2 Time profiles of millimeter bursts ............. 291
15.2.3 Observations of millimeter and microwave
bursts ......................................... 293
15.2.4 Simple spiky bursts in microwaves .............. 293
15.2.5 Microwave and hard X-ray observations of
footpoint- emission from flaring loops ......... 294
15.2.6 Double loop configuration of flaring regions ... 295
15.2.7 Modeling of microwave flares ................... 297
15.3 Small scale energy releases on the Sun ................ 299
15.3.1 XBP flares ..................................... 300
15.3.1.1 Metric type III burst emission from
an XBP flare in a coronal hole ........ 300
15.3.1.2 Microwave observations of XBP
flares ................................ 301
15.3.2 Radio observations of coronal X-ray jets ....... 303
15.3.2.1 Meterwave observations of jets ........ 303
15.3.2.2 A statistical study of jets in
microwaves ............................ 305
15.3.3 Active region transient brightenings
(ARTB's) ....................................... 305
15.3.3.1 Radio (VLA) observations .............. 306
15.3.3.2 Radio (Nobeyama) observations ......... 307
15.3.3.3 Radio (OVRO) observations ............. 307
15.3.3.4 Transient brightenings in quiet Sun
regions ............................... 308
15.3.3.5 Implications of transients for
coronal heating ....................... 308
15.4 Concluding remarks .................................... 310
References ................................................. 311
16 Coronal oscillations ....................................... 314
V.M. Nakariakov
16.1 Introduction .......................................... 314
16.2 The method of MHD coronal seismology .................. 315
16.3 Detectability of MHD waves in the corona .............. 316
16.4 Compressive waves in polar plumes ..................... 318
16.4.1 Observations ................................... 318
16.4.2 Interpretation as slow magnetoacoustic waves ... 319
16.5 Search for Alfven waves ............................... 322
16.5.1 Theoretical aspects ............................ 322
16.5.2 Observational aspects .......................... 323
16.6 Compressive waves in long loops ....................... 324
16.6.1 Observations and interpretation ................ 324
16.6.2 Seismologic implications ....................... 327
16.7 Flare-generated oscillations of coronal loops ......... 327
16.7.1 Observations ................................... 327
16.7.2 Determination of the magnetic field ............ 329
16.7.3 Determination of transport coefficients ........ 330
16.8 EIT or coronal Moreton waves .......................... 331
16.9 Conclusions ........................................... 332
References ................................................. 332
17 Probing the Sun's hot corona ............................... 335
K.J.H. Phillips and B.N. Dwivedi
17.1 The solar corona ...................................... 335
17.2 The spacecraft era .................................... 338
17.3 Heating of the corona: theory ......................... 341
17.4 Observational evidence: transient brightenings ........ 344
17.5 Physical characteristics of the corona ................ 346
17.6 Observational evidence: wave motions .................. 349
17.7 Conclusions ........................................... 351
References ................................................. 351
18 Vacuum-ultraviolet emission line diagnostics for solar
plasmas .................................................... 353
B.N. Dwivedi, A. Mohan and K. Wilhelm
18.1 The Sun in the ultraviolet emission lines ............. 353
18.1.1 SUMER spectrograph ............................. 354
18.2 Atomic processes ...................................... 355
18.2.1 Emission lines ................................. 356
18.2.2 Coronal model approximation .................... 357
18.2.3 Electron collisional excitation and
de-excitation .................................. 358
18.2.4 Proton collisional excitation and
de-excitation .................................. 358
18.2.5 Ionization balance ............................. 359
18.3 Plasma diagnostics .................................... 359
18.3.1 Emission measure analysis ...................... 360
18.3.2 Electron-density diagnostics ................... 362
18.3.3 Electron-temperature diagnostics ............... 363
18.3.4 Abundance determination ........................ 364
18.4 Some new results from SUMER ........................... 365
18.4.1 Coronal holes and the solar wind ............... 365
18.4.2 The "red/blue" Sun ............................. 367
18.4.3 Explosive events ............................... 368
18.4.4 Sunspot transition region oscillations ......... 369
18.4.5 Solar flare observed by SUMER .................. 370
18.5 Conclusions ........................................... 370
References ................................................. 371
19 Solar wind ................................................. 374
E. Marsch, W.I. Axtoid and J.E. McKenzie
19.1 The solar wind ........................................ 374
19.2 Basic energy considerations ........................... 375
19.2.1 Historic restrospective: Parker's model ........ 375
19.2.2 Problems with a polytropic single-fluid
model .......................................... 375
19.2.3 Energy requirements on heavy ions .............. 376
19.3 Solar corona and wind in three dimensions ............. 377
19.3.1 Types of solar wind ............................ 377
19.3.2 Three-dimensional solar corona ................. 377
19.3.3 Electron density and temperature ............... 379
19.4 Fast solar wind ....................................... 379
19.4.1 Coronal and in-situ observations ............... 379
19.4.2 Basic model equations .......................... 383
19.4.3 Heating functions .............................. 385
19.4.4 Some results from model calculations ........... 386
19.4.5 The wave spectrum: origin, evolution and
dissipation .................................... 389
19.4.6 Critical issues in the models .................. 390
19.5 Slow solar wind ....................................... 391
19.5.1 Observations of slow flows ..................... 391
19.5.2 Models of the closed corona and slow wind ...... 392
19.6 Sources of the solar wind ............................. 394
19.6.1 Chromospheric network .......................... 394
19.6.2 Network pico-flares ............................ 395
19.6.3 Heating of the quiet corona .................... 396
19.6.4 Some consequences of network flares ............ 396
19.7 Problems .............................................. 397
19.7.1 Problems with the observations ................. 397
19.7.2 Problems with the theory ....................... 398
19.8 Conclusions ........................................... 399
References ................................................. 400
20 Solar observing facilities ................................. 403
B. Fleck and C.U. Keller
20.1 Introduction .......................................... 403
20.2 Ground-based instruments .............................. 403
20.2.1 Present ........................................ 406
20.2.1.1 General purpose telescopes ............ 406
20.2.1.2 Synoptic telescopes ................... 408
20.2.1.3 Synoptic networks ..................... 412
20.2.1.4 Synoptic radio telescopes ............. 413
20.2.2 Future plans ................................... 414
20.2.2.1 General purpose telescopes ............ 414
20.2.2.2 Synoptic telescopes ................... 415
20.2.2.3 Radio telescopes ...................... 416
20.3 Current and planned suborbital missions ............... 416
20.4 Space missions ........................................ 417
20.4.1 In operation ................................... 417
20.4.1.1 Ulysses ............................... 417
20.4.1.2 Yohkoh ................................ 418
20.4.1.3 Wind .................................. 419
20.4.1.4 SOHO .................................. 420
20.4.1.5 ACE ................................... 423
20.4.1.6 TRACE ................................. 423
20.4.1.7 GOES/Solar X-ray imager ............... 424
20.4.1.8 CORONAS-F ............................. 424
20.4.1.9 Genesis ............................... 425
20.4.1.10 HESSI ................................ 425
20.4.2 In development and under study ................. 426
20.4.2.1 Solar-B ............................... 426
20.4.2.2 STEREO ................................ 427
20.4.2.3 Space Solar Telescope-SST ............. 428
20.4.2.4 SDO ................................... 428
20.4.2.5 Solar Orbiter ......................... 429
20.4.2.6 Solar probe ........................... 430
20.4.2.7 Solar sentinels ....................... 432
20.5 Conclusions ........................................... 432
References ................................................. 432
Index ......................................................... 435
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