Contemporary Issues in Estuarine Physics

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 7
List of contributors......Page 8
Preface......Page 11
1.1. Classification of estuaries on the basis of water balance......Page 13
1.2. Classification of estuaries on the basis of geomorphology......Page 15
1.3. Classification of estuaries on the basis of vertical structure of salinity......Page 16
1.4. Classification of estuaries on the basis of hydrodynamics......Page 18
References......Page 23
2.2. The estuarine circulation......Page 24
2.3. The stratification......Page 28
2.4. The salt balance......Page 31
2.5. The coupled equations......Page 33
2.6. Temporal variability of the estuarine salinity structure and circulation......Page 35
2.7. Estuarine classification......Page 36
References......Page 38
3.1. Introduction......Page 39
3.2. Governing equations......Page 41
3.3. Scaling momentum......Page 42
3.4. Scaling continuity......Page 43
3.5. Short estuaries......Page 46
3.6. Long, shallow, funnel-shaped estuaries......Page 47
3.7. Long, deep, non-convergent estuaries......Page 51
3.8. Long, shallow, non-convergent estuaries......Page 54
3.9. Tidal asymmetry in shallow estuaries......Page 56
3.10. Tides in long, intermediate-depth, equilibrium estuaries......Page 59
3.11. Tides in long, non-equilibrium estuaries......Page 61
3.12. Tides in long, near-equilibrium estuaries......Page 63
3.13. Tides in intermediate-length estuaries......Page 64
3.14. Compact solutions for tides in intermediate-length, non-convergent estuaries......Page 66
3.15. Discussion and conclusions......Page 67
References......Page 72
4.2. Examples of estuarine variability......Page 74
4.2.1 Intratidal variability......Page 75
4.2.2 Subtidal variability......Page 78
4.2.3 Non-linear tidal variability and internal asymmetry......Page 83
4.3. A formal analysis of estuarine circulation......Page 87
4.4. The tidal circulation......Page 90
4.5. The density and salinity fields......Page 96
4.6. The circulation caused by internal tidal asymmetry......Page 98
4.7. Residual circulation modes in general......Page 103
4.8. The Hansen and Rattray problem......Page 105
4.9. The circulation due to tidal non-linearities......Page 108
4.10. The total estuarine circulation......Page 109
References......Page 111
5.1. Introduction......Page 112
5.2. Driving mechanisms......Page 113
5.3. Development of lateral density gradients......Page 115
5.4. Differential advection......Page 118
5.5. Flow curvature......Page 120
5.6. Effects of Coriolis......Page 124
5.7. Effects of stratification......Page 126
5.8. Diffusive boundary layer......Page 128
5.9.1. Role in along-channel dynamics......Page 129
5.10. Role of secondary flows in dispersion......Page 133
5.11. Summary......Page 134
References......Page 135
6.2. Model equations......Page 137
6.4. Wind-driven viscous flow in a closed shallow basin......Page 138
6.4.1. The horizontal velocities in wind-driven flow......Page 140
6.4.2. Wind-driven transport......Page 141
6.4.3. Solution near mid-basin......Page 142
6.5.1. Equations of motion and boundary conditions......Page 143
Perturbation and Taylor series expansion......Page 145
Lowest-order problem......Page 146
6.5.2. Fluctuating sea level......Page 147
6.5.3. Fluctuating velocities......Page 149
6.6. Residual circulation due to tides......Page 150
The Eulerian mean flow......Page 151
Forcing......Page 152
6.6.2. Residual sea level......Page 153
Transport streamfunction......Page 154
Three-dimensional Eulerian mean flow......Page 155
References......Page 156
7.2.1. Fickian diffusion......Page 157
7.3.1. The cascade......Page 162
7.3.2. Mixing (dispersion) in turbulent flows......Page 164
7.3.3. Reynolds averaging......Page 167
7.3.4. Turbulent kinetic energy......Page 170
7.3.4. Effects of stratification......Page 172
7.3.5. Stratified turbulence in San Francisco Bay......Page 176
7.4.1. Horizontal turbulent mixing......Page 179
7.4.2. Averaging and its consequences......Page 180
7.4.3. Advection–diffusion of the subtidal salinity field......Page 182
7.4.4. Determining Kx from observations......Page 183
7.4.5. Shear flow dispersion of tidal currents......Page 184
7.4.6. Dispersion by gravitational circulation......Page 186
7.4.7. Other processes: dead zones, chaos, etc.......Page 189
7.4.8. Synthesis: mixing and salinity intrusion in Northern San Francisco Bay......Page 191
Notes......Page 194
References......Page 195
8.2. Phenomenology......Page 198
8.3. Classification schemes......Page 202
8.4. Evaluation of the semigeostrophic balance......Page 208
8.5. The role of bottom friction......Page 212
8.6. The role of vertical mixing......Page 217
8.7. The role of wind......Page 222
8.8. Small-scale front classification......Page 233
8.9. Structure and dynamics of small-scale fronts......Page 236
8.10. Conclusion......Page 252
References......Page 253
9.1. Introduction......Page 259
9.2. Terminology......Page 260
9.3. Water, salt and heat budgets......Page 261
9.3.1. Water budget......Page 262
9.3.2. Salt budget......Page 263
9.3.3. Heat budget......Page 265
9.3.4. Water density......Page 266
9.4. Circulation response......Page 267
9.5. Longitudinal structure......Page 273
9.6. Seasonal variability......Page 275
9.7. Examples of low-inflow estuaries......Page 277
9.8. Summary......Page 279
References......Page 280
10.1. Introduction......Page 285
10.2. Transport–reaction equations for water quality constituents......Page 286
10.3.1. Scaling......Page 289
Flushing time......Page 290
Residence time......Page 294
Age......Page 296
10.3.3. Implications of transport time scales for water quality......Page 297
10.3.4. A simple model of horizontal transport, sources, and sinks......Page 299
10.4. Vertical variability and transport processes......Page 302
10.4.1. Effects of stratification and turbulence......Page 303
10.4.2. Significance of the time scale of stratification......Page 306
10.4.3. Interactions of sinking with vertical mixing......Page 307
10.5. Hourly scale variability......Page 308
10.5.1. Horizontal scalar flux in a tidal system......Page 310
10.5.3. Implications of high-frequency variability for sampling......Page 313
References......Page 315
Index......Page 320