FOREWORD xi
CHAPTER 1. THE OCEAN IN THE EARTH SYSTEM: EVOLUTION AND REGULATION 1
Philippe BERTRAND
1.1. The Earth system and its components 1
1.1.1. A system is a set of objects whose limit is arbitrary, but pertinent 1
1.1.2. One system is necessarily built into another 3
1.1.3. The Earth is a "closed" system 4
1.1.4. The major components of the Earth system 7
1.1.5. What is the biosphere? 8
1.2. The ocean, from its origins 9
1.2.1. Was there an ocean 4.4 billion years ago? 9
1.2.2. The origin of water on Earth (4.5 - 4 billion years ago) 9
1.2.3. The ocean and the end of the "Venus" phase of the Earth's history (between 4.5 and 4 billion years ago) 10
1.2.4. Why are there oceans on Earth and a "Venus inferno" on Venus? 13
1.2.5. The ocean, cradle of the first living creatures (between 4.4 and 3.5 billion years ago) 16
1.3. The ocean, oxygen and the evolution of life forms 18
1.3.1. The essential characteristics had been selected in the ocean before the Cambrian period, over 540 million years ago 18
1.3.2. How did oxygen accumulate? 21
1.3.3. The first important accumulation of oxygen (around 2.5 billion years ago) 25
1.3.4. A moderate increase in oxygenation (between 2.5 and 0.5 billion years ago) 26
1.3.5. The second important accumulation of oxygen (between 500 and 350 million years ago) 27
1.4. The regulation of the greenhouse effect by the ocean 29
1.4.1. There is no life without a minimum greenhouse effect 29
1.4.2. The regulation of the greenhouse effect by the ocean 30
1.5. Oceanic photosynthesis regulates itself on a short timescale 36
1.5.1. When the ocean is deficient in nitrate 38
1.5.2. When the ocean has an excess of nitrate 40
1.5.3. The regulation of the N/P ratio 41
1.6. Conclusion 43
1.6.1. The ocean in the Earth system 43
1.6.2. The anthropogenic disturbance of the Earth system 45
1.6.3. And life among all that? 47
1.7. Acknowledgments 49
1.8. Bibliography 49
CHAPTER 2. THE OCEAN AND THE CLIMATE SYSTEM 55
Pascale DELECLUSE
2.1. Introduction 55
2.2. Climate change 55
2.2.1. The report on the findings 56
2.2.2. Interpretation of the observed changes 58
2.2.3. The Earth's radiative equilibrium and greenhouse gases 59
2.2.4. The role of greenhouse gases - GHG60
2.2.5. Scenarios and projections 63
2.3. Physics and dynamics 67
2.3.1. Rotation, Coriolis, geostropy 69
2.3.2. An ocean moved by the wind 71
2.3.3. Ekman, spiral, transport, pumping, upwelling and downwelling 71
2.3.4. Interior ocean and western boundary currents 77
2.3.5. An ocean moved by thermohaline fluxes 80
2.3.6. Stratification, mixed layer, thermocline 82
2.3.7. Formation of water masses, convection and subduction 83
2.3.8. Schematization of global circulation: the great conveyor belt 85
2.4. Some key elements for understanding the ocean's role in the climate 88
2.4.1. Typical times 88
2.4.2. Ocean-atmosphere in the tropics 90
2.4.3. Other types of variability 95
2.4.4. Climatic surprises 97
2.5. Some questions for the future 100
2.6. Bibliography 102
CHAPTER 3. OCEAN-ATMOSPHERE INTERACTIONS 105
Laurence EYMARD and Gilles REVERDIN
3.1. Introduction: what are ocean-atmosphere interactions? 105
3.2. Interface processes and their role in the coupled system 106
3.2.1. Radiative fluxes 107
3.2.2. Turbulent fluxes 109
3.2.3. Water exchanges between the ocean and atmosphere 115
3.2.4. Other exchanges of matter 118
3.2.5. Flux measurement 125
3.3. Examples of energy exchanges 129
3.3.1. Tropical cyclones 129
3.3.2. Surface temperature fronts 132
3.3.3. The interactions close to strong oceanic fronts 134
3.3.4. Marginal ice zones and associated air-sea fluxes 137
3.3.5. The example of the impact of the iron supply from Saharan aerosols 140
3.4. Conclusion 142
3.5. Bibliography 143
CHAPTER 4. MARINE BIOGEOCHEMICAL CYCLES 145
Louis LEGENDRE
4.1. Introduction: geochemistry, biogeochemistry and marine biogeochemistry 145
4.1.1. Geochemistry and cosmochemistry 145
4.1.2. Biogeochemistry and marine biogeochemistry 147
4.2. A fundamental characteristic of the Earth's system: biogeochemical cycles 149
4.3. Carbon: at the heart of living matter 152
4.3.1. Carbon in large natural reservoirs 153
4.3.2. Biogeochemical cycles of carbon 156
4.4. Oxygen: a poison that Earth cannot do without 166
4.4.1. The Great Oxygenation Event 168
4.4.2. Biogeochemical cycles of oxygen 169
4.5. Nitrogen: a chemical element over which countries have fought in the past 174
4.5.1. Nitrogen, abundant but difficult to access 174
4.5.2. Biogeochemical cycles of nitrogen 176
4.6. Phosphorus: a chemical element over which countries may fight in future 182
4.6.1. Phosphorus, not very abundant or exploitable 182
4.6.2. Biogeochemical cycles of phosphorus 182
4.7. Biogeochemical equilibria and human societies: problems 185
4.8. Bibliography 186
CHAPTER 5. OCEAN ACIDIFICATION AND ITS CONSEQUENCES 189
Jean-Pierre GATTUSO, Lina HANSSON and Frederic GAZEAU
5.1. Introduction 189
5.1.1. What is ocean acidification? 190
5.1.2. A brief history of research on the acidification of oceans 193
5.1.3. Main research programs 197
5.2. Observations 197
5.2.1. Past changes 197
5.2.2. Recent changes 199
5.3. Projections 201
5.4. Impacts of ocean acidification 204
5.4.1. Impacts on organisms and communities 204
5.4.2. Impacts on biogeochemical cycles 219
5.4.3. Economy and society 221
5.5. What are the solutions? 225
5.5.1. The reduction of CO2 emissions 226
5.5.2. Geoengineering techniques 227
5.5.3. Adaptation measures 228
5.6. Conclusion 229
5.7. Acknowledgments 231
5.8. Appendix 231
5.8.1. Carbonate chemistry of carbonates and biogeochemical processes 231
5.9. Bibliography 233
LIST OF AUTHORS 255
INDEX 257
