Ocean Dynamics and the Carbon Cycle: Principles and Mechanisms

Half-title......Page 3
Title......Page 5
Copyright......Page 6
Contents......Page 7
Preface......Page 11
Acknowledgements......Page 13
Illustration credits......Page 14
Part I Introduction......Page 15
1.1 What is special about water?......Page 17
1.2.1 How does atmospheric composition affect radiative heating?......Page 19
1.2.3 How does the ocean affect the redistribution of heat?......Page 20
1.3.1 How does the ocean store carbon?......Page 21
1.3.2 How is carbon exchanged between the atmosphere and ocean?......Page 22
1.3.4 How does ocean circulation affect the ecosystem?......Page 23
1.4 How have climate and life evolved on the planet?......Page 24
1.4.1 How has atmospheric carbon dioxide decreased over geological timescales?......Page 25
1.4.3 How has atmospheric carbon dioxide varied with glacial--interglacial cycles?......Page 27
1.4.4 How is atmospheric carbon dioxide changing today?......Page 28
1.5 Summary and outlook......Page 29
1.6 Recommended reading......Page 30
2.1 Ocean circulation......Page 31
2.1.1 How does the surface flow vary?......Page 32
2.1.2 How does the ocean vary in the vertical?......Page 34
2.1.3 How do water masses spread over the globe?......Page 52
2.2.1 How does the atmosphere circulate?......Page 56
2.2.2 How do the atmosphere and ocean transfer heat together over the globe?......Page 58
2.2.3 Summary......Page 59
2.3 Life and nutrient cycles in the ocean......Page 60
2.3.1 Biological cycling of nutrients......Page 61
2.3.2 Where is organic matter produced?......Page 62
2.3.4 Summary......Page 63
2.4 The carbon cycle in the ocean......Page 64
2.4.1 The vertical distribution of carbon......Page 65
2.4.2 Air-sea exchange of carbon dioxide......Page 66
2.6 Questions......Page 68
2.7 Recommended reading......Page 70
Part II Fundamentals......Page 71
3.1.1 Advection......Page 73
3.1.2 Molecular diffusion......Page 75
3.1.3 Stirring and mixing......Page 77
3.2.1 Generic tracer budget......Page 79
3.2.3 Molecular diffusion......Page 80
3.2.5 Eddy transfer of tracers......Page 81
3.2.6 How are eddy fluxes represented?......Page 83
3.3 What is the effect of a time-varying, eddy circulation?......Page 85
3.3.2 What is the effect of waves on how particles move by the seashore?......Page 86
3.3.3 Relationship to eddy volume flux......Page 87
3.3.5 Large-scale examples of tracer transport over the globe......Page 90
3.4 Summary......Page 92
3.5 Questions......Page 93
3.6 Recommended reading......Page 95
4.1.1 What are the external forces?......Page 96
4.1.2 What is the effect of rotation?......Page 97
4.2 How is the surface circulation determined?......Page 98
4.2.1 Geostrophic balance......Page 100
4.2.2 Ageostrophic and Ekman flow......Page 102
4.3.3 How does the geostrophic flow vary with depth?......Page 106
4.4.1 Surface circulation and wind forcing......Page 110
4.4.2 Air-sea exchange of heat......Page 112
4.4.3 Air-sea freshwater flux andsurface salinity......Page 115
4.4.4 Air-sea forcing of surface density......Page 117
4.5 Summary......Page 119
4.6 Questions......Page 120
4.7 Recommended reading......Page 122
5.1 Photosynthesis and respiration......Page 123
5.2 What are marine microbes made of?......Page 124
5.2.1 How does the elemental composition of microbes vary?......Page 125
5.2.2 How are organic molecules produced in a cell?......Page 126
5.3.1 Population growth and nutrient limitation......Page 128
5.3.2 How do microbes acquire dissolved nutrients from the water?......Page 129
5.3.3 Nutrient uptake and population growth......Page 132
5.3.4 How does light affect microbial growth?......Page 133
5.3.5 How does temperature affect phytoplankton growth?......Page 135
5.4 Phytoplankton community structure......Page 136
5.4.1 How does phytoplankton community structure vary with the environment?......Page 137
5.4.2 What regulates the pattern of community structure?......Page 138
5.5 Primary production and the fate of organic matter......Page 140
5.5.2 What is the fate of the organic matter produced by phytoplankton?......Page 141
5.5.3 Export production......Page 143
5.5.4 What is the fate of exported organic carbon?......Page 144
5.6 Consequences for ocean biogeochemistry......Page 145
5.6.1 Contrasts in nutrient cycles......Page 147
5.6.2 Modulation of regional productivity by iron: High Nitrate Low Chlorophyll regimes......Page 149
5.7 Summary......Page 151
5.8 Questions......Page 152
5.9 Recommended reading......Page 154
6.1 Solubility of carbon dioxide......Page 155
6.2.1 Dissolved inorganic carbon......Page 158
6.3 What controls DIC in the surface ocean?......Page 161
6.3.1 Temperature, solubility andsurface DIC......Page 162
6.3.2 Charge balance and alkalinity......Page 163
6.3.4 How does alkalinity affect DIC?......Page 164
6.3.5 What controls regional variations in surface HCO3- and CO32-?......Page 165
6.3.6 How does pH affect buffering and the partitioning of DIC?......Page 167
6.3.7 Regulation of DIC by temperature and alkalinity in the surface ocean......Page 168
6.4.1 Variation of DIC with depth......Page 169
6.4.2 Variation of alkalinity with depth......Page 170
6.4.3 What determines the depth at which sinking calcium carbonate dissolves?......Page 171
6.5.1 Buffering of the seawatercarbonate system......Page 172
6.6 Air-sea exchange of carbon dioxide......Page 175
6.6.2 The air-sea flux of CO2......Page 176
6.6.3 What prevents a local air-sea equilibrium?......Page 177
6.6.4 Departures from a local equilibrium for surface DIC......Page 180
6.6.5 Timescale of air--sea equilibration......Page 181
6.7 Summary......Page 182
6.8 Questions......Page 184
6.9 Recommended reading......Page 185
Part III Physical Phenomena and their Biogeochemical Signals......Page 187
7.1.1 Turbulence and the surface mixed layer......Page 189
7.1.2 Mixed-layer physics......Page 191
7.1.3 Mixed-layer cycle in the subtropical North Atlantic......Page 193
7.2.1 Mid- and high-latitude variability......Page 194
7.2.2 Tropical and low-latitude variability......Page 199
7.2.3 El Nino-Southern Oscillation......Page 200
7.2.4 Seasonal succession in phytoplankton community structure......Page 201
7.3.1 Seasonality in the subtropical North Atlantic......Page 202
7.4.2 Shelf-sea regimes and fronts......Page 205
7.4.3 Primary production in the shelf seas......Page 206
7.4.4 Seasonality in the carbon cycle: case study of the North Sea......Page 207
7.5 Summary......Page 209
7.6 Questions......Page 210
7.7 Recommended reading......Page 212
8.1 What are ocean gyres?......Page 213
8.1.1 Surface signals......Page 214
8.2 What are western boundary currents?......Page 219
8.2.1 What is the structure and transport of the Gulf Stream?......Page 220
8.3 A theoretical view of ocean gyres and boundary currents......Page 221
8.3.1 What is vorticity?......Page 222
8.3.2 How does the ocean respond to an input of vorticity?......Page 224
8.3.3 Sverdrup balance......Page 225
8.3.4 How is the gyre circulation completed?......Page 226
8.3.5 The effect of a sloping sea floor on the gyre circulation......Page 228
8.4.1 How does the Antarctic Circumpolar Current vary?......Page 233
8.5 Summary......Page 236
8.6 Questions......Page 238
8.7 Recommended reading......Page 240
9.1 How does eddy variability alter over the globe?......Page 241
9.2.2 How do eddies in the atmosphere and ocean acquire their energy?......Page 245
9.2.3 What is the dynamical structure of the eddies?......Page 246
9.2.4 What is the characteristic horizontal scale for eddies?......Page 248
9.2.5 What are the characteristic timescales for eddies to grow?......Page 250
9.2.6 Summary......Page 251
9.3.1 Atmospheric weather systems......Page 252
9.3.2 Eddy sea-surface temperature fluxes......Page 253
9.3.3 Eddy stirring in the thermocline......Page 255
9.3.4 How do eddies advect anddiffuse tracers?......Page 256
9.3.5 How to parameterise eddies?......Page 257
9.3.6 The competing effects of jetsand eddies......Page 258
9.5 Questions......Page 263
9.6 Recommended reading......Page 265
10.1 How does ventilation vary over the globe?......Page 266
10.1.1 Ventilation tracers in the upper mode waters......Page 267
10.1.3 Deep and bottom waters......Page 272
10.2 A mechanistic view of ventilation......Page 273
10.2.2 How is the timing of ventilation controlled?......Page 275
10.2.3 How is ventilation connected to the vertical velocity?......Page 277
10.2.4 What is the rate of ventilation for the upper ocean?......Page 279
10.2.5 The effect of ventilation of the thermocline......Page 282
10.2.6 How is fluid exchanged across gyre boundaries?......Page 284
10.3 Summary......Page 287
10.4 Questions......Page 288
10.5 Recommended reading......Page 289
11.1 How are basin-scale contrasts in biological productivity maintained?......Page 290
11.1.1 Boundary current transfer......Page 291
11.1.2 Advection of nutrients into the mixed layer......Page 293
11.1.3 Convective transfer of nutrients......Page 295
11.2 How is biological productivity sustained in ocean deserts?......Page 297
11.2.2 Diffusive transfer......Page 298
11.2.3 Time-dependent upwelling......Page 299
11.2.4 Horizontal transfers of nutrients into the subtropical gyre......Page 302
11.2.5 Other nutrient sources......Page 303
11.3 What sets the nutrient distributions in the oceaninterior?......Page 306
11.3.2 Estimating the regenerated contribution using oxygen observations......Page 307
11.3.3 Nutrient utilisation in the Atlantic and Pacific basins......Page 308
11.4 Quantifying the ocean's carbon reservoirs......Page 310
11.4.2 Subsurface ocean......Page 311
11.4.4 How are the carbon reservoirs distributed in the ocean?......Page 313
11.6 Questions......Page 317
11.7 Recommended reading......Page 318
12.1.1 Properties of the deep ocean......Page 320
12.1.2 Overturning cells......Page 322
12.1.3 Why is the overturning different in the Atlantic and Pacific?......Page 324
12.1.4 Heat transfer......Page 328
12.1.5 Summary......Page 329
12.2.1 Surface exchange of density......Page 330
12.2.2 Convection......Page 331
12.2.3 Mixing of dense water......Page 333
12.2.4 Spreading of dense water......Page 335
12.2.5 Meridional overturning andits variability......Page 337
12.2.6 Why is the formation of deep water important for the carbon cycle?......Page 339
12.3.1 Idealised abyssal model......Page 341
12.3.2 Effect of topography......Page 343
12.3.3 Effect of eddy stirring......Page 344
12.3.4 Summary......Page 345
12.4 How is dense water returned to the surface?......Page 346
12.4.1 How does the meridional overturning operate across the Southern Ocean?......Page 347
12.4.2 Mixing in the Southern Ocean......Page 349
12.4.3 Summary......Page 350
12.4.4 Southern Ocean nutrient and carbon cycling......Page 352
12.6 Questions......Page 354
12.7 Recommended reading......Page 356
Part IV Synthesis......Page 357
13.1.1 Global integral constraints......Page 359
13.1.3 Variations in the ocean-atmosphere carbon system......Page 360
13.2.1 Transient response to carbon emissions......Page 361
13.2.2 Carbonate chemistry......Page 362
13.2.4 How does the carbonate system vary over 10000 years?......Page 364
13.2.5 Summary......Page 367
13.3 Glacial-interglacial changes in atmospheric CO2......Page 368
13.3.2 Temperature and solubility changes......Page 369
13.3.4 Changes in the export oforganic carbon......Page 371
13.4 Water-mass formation and transformation......Page 374
13.4.1 Walin isopycnal view......Page 375
13.5 Summary......Page 380
13.6 Questions......Page 381
13.7 Recommended reading......Page 382
14.1 Interconnections between the physics, chemistryand biology......Page 384
14.2 Research approaches......Page 386
14.3 Challenges......Page 387
14.3.3 What does the future hold?......Page 388
A.1.2 Material derivative......Page 390
A.1.3 Taylor expansion......Page 391
A.2.1 What are the external forces?......Page 392
A.2.2 What is the effect of rotation?......Page 393
A.2.3 Vector components of the momentum equation......Page 395
A.2.4 Scale analysis of the momentum equation......Page 396
A.3 Solving the carbonate chemistry system......Page 398
Biological and chemical symbols......Page 400
Physical symbols......Page 401
Mathematical definitions......Page 404
Biological glossary......Page 405
Chemical glossary......Page 406
Physical glossary......Page 407
Answers......Page 411
References......Page 418
Index......Page 430