Note: Front Cover -- Ocean Circulation and Climate: A 21st Century Perspective -- Copyright -- Contents -- Contributors -- Acknowledgments -- Cover Graphics -- Preface -- Part I: The Ocean's Role in the Climate System -- Chapter 1: The Ocean as a Component of the Climate System -- 1. Setting the Scene -- 2. The Ocean as an Exchanging Earth System Reservoir -- 3. Atmosphere-Ocean Fluxes and Meridional Transports -- 4. Global-Scale Surface and Deep Ocean Circulations -- 5. Large-Scale Modes of Variability Involving the Ocean -- 6. The Ocean's Role in Past Climate Change -- 7. The Ocean in the Anthropocene -- 8. Concluding Thoughts -- Acknowledgments -- References -- Chapter 2: Paleoclimatic Ocean Circulation and Sea-Level Changes -- 1. Introduction -- 2. Reconstructing Past Ocean States -- 2.1. Proxies for Past Ocean Circulation -- 2.1.1. Nutrient Water Mass Tracers -- 2.1.2. Conservative Water Mass Tracers -- 2.1.3. Circulation Rate Tracers -- 2.1.4. Other Tracers -- 2.2. Past Sea-Level Proxies -- 2.2.1. Coastal Morphology and Corals -- 2.2.2. Sediment Cores -- 2.2.3. Manmade Sea-Level Indicators -- 2.3. Models -- 3. The Oceans in the Quaternary -- 3.1. The Last Glacial Maximum -- 3.2. Abrupt Glacial Climate Changes -- 3.2.1. Deglaciation -- 3.3. Glacial Cycles -- 3.4. Interglacial Climates -- 4. The Deeper Past -- 4.1. Challenges of Deep-Time Paleoceanography -- 4.2. The Oceans During the Mid-Cretaceous Warm Period -- 5. Outlook -- Acknowledgments -- References -- Part II: Ocean Observations -- Chapter 3: In Situ Ocean Observations: A Brief History, Present Status, and Future Directions -- 1. Introduction -- 2. Development of Present Observational Capability -- 2.1. Late Nineteenth to Mid-Twentieth Centuries -- 2.2. Second Half of Twentieth Century -- 2.3. Twenty-First Century: Consolidation of Capabilities and Growth of Sustained Observations. , 3. Emerging and Specialized Ocean Observing Technologies -- 3.1. Advanced Observing Platforms -- 3.2. Specialized Observing Systems and Technologies -- 3.3. New Sensors -- 4. Changes in Data Volume and Coverage and Implication for Synthesis Products -- 5. The Future: Outstanding Issues and a New Framework for Global Ocean Observing -- 5.1. Building on OceanObs'09 -- 6. Conclusions -- References -- Chapter 4: Remote Sensing of the Global Ocean Circulation -- 1. Introduction -- 2. Ocean General Circulation -- 3. Variability of the Large-Scale Ocean Circulation -- 3.1. Sea Surface Height -- 3.2. Ocean Mass and Bottom Pressure -- 3.3. Global Mean Sea-Level Change (see also Chapter 27) -- 3.4. Forcing by the Atmosphere and Air-Sea Interaction -- 4. Mesoscale Eddies and Fronts -- 4.1. Mapping the Eddy Field -- 4.2. Wave Number Spectra and the Ocean Energy Cascade -- 4.3. Seasonal and Interannual Variations in Eddy Energy -- 4.4. Tracking Individual Eddies -- 4.5. Surface Currents from Multisensor Mapping -- 4.6. Eddy Fluxes of Ocean Properties (see also Chapter 8) -- 4.7. Submesoscale Dynamics -- 4.8. Eddies and Biogeochemical Processes -- 5. Summary and Outlook -- Acknowledgments -- References -- Part III: Ocean Processes -- Chapter 5: Exchanges Through the Ocean Surface -- 1. Introduction -- 2. Air-Sea Exchange Formulae and Climatological Fields -- 2.1. Air-Sea Exchange Formulae -- 2.2. Climatological Fields -- 3. Measurement Techniques and Review of Datasets -- 3.1. Flux Measurement and Estimation Techniques -- 3.1.1. Advances in Parameterizations and In Situ Flux Measurements -- 3.1.2. High Quality In Situ Surface Flux Datasets -- 3.2. Flux Datasets: Overview of Recent Products -- 3.2.1. Atmospheric Reanalyses -- 3.2.2. Satellite Observations -- 3.2.3. In Situ Observations -- 3.2.4. Blended Products -- 3.3. Flux Datasets: Evaluation Techniques. , 4. Variability and Extremes -- 4.1. Impacts of Large-Scale Modes of Variability on Surface Fluxes -- 4.2. Surface Flux Response to Anthropogenic Climate Change -- 4.3. Transfers Under Extreme Conditions -- 5. Ocean Impacts -- 5.1. Impacts on Near-Surface Ocean Layer Properties, Water Mass Transformation -- 5.2. Impacts of Surface Fluxes on Ocean Circulation -- 6. Outlook and Conclusions -- 6.1. Prospects for Improved Flux Datasets -- 6.2. Prospects for Enhanced Observational Constraints -- 6.3. Conclusions -- Acknowledgments -- References -- Chapter 6: Thermodynamics of Seawater -- 1. Introduction -- 2. Absolute Salinity SA and Preformed Salinity S* -- 2.1. Reference-Composition Salinity SR -- 2.2. Absolute Salinity SA -- 2.3. Preformed Salinity S* -- 3. The Gibbs-Function Approach to Evaluating Thermodynamic Properties -- 4. The First Law of Thermodynamics and Conservative Temperature Θ -- 5. The 48-Term Expression for Specific Volume -- 6. Changes to Oceanographic Practice Under TEOS-10 -- 7. Ocean Modeling Using TEOS-10 -- 8. Summary -- Acknowledgments -- References -- Chapter 7: Diapycnal Mixing Processes in the Ocean Interior -- 1. Introduction -- 2. Mixing Basics -- 3. Turbulence in and Below the Surface Mixed Layer -- 3.1. Langmuir Turbulence -- 3.2. Inertial Motions -- 3.3. An Equatorial Example -- 3.4. Fronts and Other Lateral Processes -- 4. Mixing in the Ocean Interior -- 4.1. Internal Wave Breaking -- 4.1.1. Dissipation Near Internal Tide Generation Sites -- 4.1.2. Dissipation Near-Inertial Wave Generation Sites -- 4.1.3. Wave-Wave Interactions -- 4.1.4. Distant Graveyards -- 4.2. Mixing in Fracture Zones -- 4.3. Mesoscale Dissipation as a Source of Turbulent Mixing -- 4.4. In-Depth Example: Southern Ocean Mixing (see also Chapter 18) -- 5. Discussion -- 5.1. Finescale Parameterizations of Turbulent Mixing. , 5.2. Global Values and Patterns -- 5.3. Representing Patchy Mixing in Large-Scale Models: Progress and Consequences -- 6. Summary and Future Directions -- Acknowledgments -- References -- Chapter 8: Lateral Transport in the Ocean Interior -- 1. Introduction -- 2. Theory of Mass, Tracer, and Vector Transport -- 2.1. Fundamental Equations -- 2.1.1. Primitive Equations -- 2.1.2. Minimal-Disturbance Planes and Slopes -- 2.1.3. Density-Coordinate Continuity and Tracer Equations -- 2.2. Steady, Conservative Equations -- 2.3. Reynolds-Averaged Equations -- 2.4. Diffusion by Continuous Movements -- 2.4.1. Diagnosing Eigenvectors, Eigenvalues, and Principal Axes of Diffusivities -- 2.5. Sources of Anisotropy in Oceanic Diffusion -- 2.6. The Veronis Effect -- 2.7. Streamfunction and Diffusivity -- 3. Observations and Models of Spatial Variations of Eddy Statistics -- 4. Mesoscale Isoneutral Diffusivity Variation Parameterizations -- 4.1. Parameterizations Versus Diagnosed K -- 4.1.1. Eddy Scales Versus Instability Scale -- 4.1.2. Eddy Versus Instability Spatial Scale -- 4.1.3. Eddy Versus Instability Time Scale -- 4.2. New Parameterization Approaches and Future Developments -- 5. Conclusions and Remaining Questions -- Acknowledgment -- References -- Chapter 9: Global Distribution and Formation of Mode Waters -- 1. Mode Water Observations -- 2. Global Water Mass Census of the Upper Ocean -- 3. Global Distribution of Mode Water -- 4. Formation of Mode Water -- 5. PV Framework -- 6. Mode Water and Climate -- 7. Conclusions -- Acknowledgments -- References -- Chapter 10: Deepwater Formation -- 1. Introduction -- 1.1. Circulation and Distribution of NADW and AABW -- 1.2. Observed Heat Content Changes in AABW -- 1.3. Observed Heat Content Changes in Upper and Lower NADW -- 2. Processes of Deepwater Formation. , 2.1. Deep Convection: The Example of Formation of Upper North Atlantic Deep Water -- 2.2. Entrainment: The Example of the Formation of the Lower North Atlantic Deep Water -- 2.3. Shelf and Under-Ice Processes: The Example of Formation of AABW -- 2.3.1. Formation Rates and Spreading of AABW -- 3. Interannual and Decadal Variability in Properties, Formation Rate, and Circulation -- 3.1. Labrador Sea Water: Variability in Properties and Formation Rate -- 3.2. Greenland-Scotland Ridge Overflow Water: Variability in Properties and Overflow Rate -- 3.3. Relationship Between Formation Rates of NADW and Changes in the AMOC -- 3.4. Antarctic Bottom Water: Variability in Properties and Formation Rate -- 4. Conclusions and Outlook -- References -- Part IV: Ocean Circulation and Water Masses -- Chapter 11: Conceptual Models of the Wind-Driven and Thermohaline Circulation -- 1. Introduction -- 2. Wind-Driven Circulation -- 2.1. Ekman Layer and Ekman Overturning Cells -- 2.2. Sverdrup Balance -- 2.3. Western Boundary Currents and Inertial Recirculation -- 2.4. Vertical Structure of the Wind-Driven Circulation -- 2.5. Role of Bottom Topography -- 3. Thermohaline Circulation -- 3.1. Energetics and Global Perspective -- 3.2. Role of the Southern Ocean and Relation to the Antarctic Circumpolar Current -- 3.3. Water Mass Formation -- 3.4. Three-Dimensional Structure of the THC -- 3.5. Feedbacks and Multiple Equilibria -- 3.6. Does the South Atlantic Determine the Stability of the THC? -- 4. Transient Behaviour of the Wind-Driven and Thermohaline Circulation -- 5. Discussion and Perspective -- Acknowledgments -- References -- Chapter 12: Ocean Surface Circulation -- 1. Observed Near-Surface Currents -- 1.1. Global Drifter Program and History of Lagrangian Observations -- 1.2. Mean Surface Circulation -- 2. Geostrophic Surface Circulation. , 2.1. High-Resolution Mean Dynamic Topography.