Ocean Currents: Physical Drivers in a Changing World opens with a general introduction to the character, measurement, and simulation of ocean currents, leading to a physical and dynamical framework for understanding the wide variety of flows encountered in the oceans. The book comprises chapters covering distinct aspects of contrasting ocean currents: broad and slow, deep and shallow, narrow and swift, large scale and small scale, low latitudes and high latitudes, and moving in horizontal and vertical planes. Through this approach the authors cover a wide range of applications, from local to global, with considerable geographical context. .

Table of contents :
1 1 The restless ocean Chapter Outline Ten big questions Organization vs. chaos Measuring the ocean-Challenges and international organization Measuring ocean currents Drift measurements Point measurements Profile measurements Radar measurements Estimating ocean currents Hydrography Bottom pressure recorders Satellite altimeters Electrical cables Computer simulation of ocean currents An ocean of scales Summary 2 Frameworks, data, and methods Chapter Outline Essential physics and scalar conservation Seawater properties, the equation of state, and neutral surfaces Conservation of mass, salt, and heat Essential dynamics-With the flow and at a fixed point Real forces The effects of Earth's rotation The equations of motion-Following the flow Advection of momentum The equations of motion-At a fixed point Scaling arguments and approximating the equations of motion Ocean and climate data products Ocean observations (Argo) Ocean reanalysis (GODAS) Ocean analysis (EN4) Air-sea fluxes (COREv2) Atmospheric reanalysis (NCEP/NCAR) Tropical cyclone tracks (IBTRaCS; HURDAT) Sea ice (NSIDC) and icebergs (IIP; BYU/NIC) Numerical models of the ocean and climate Governing equations and approximations Numerical solution Meshes, grids, and vertical coordinates Resolution, processes, and parameterizations From bespoke to community codes Coupling, complexity, and climate Particle tracking Resourcing Chapters 3-1234567891012 Exercises References 3 Surface drift, gyres, and the fate of plastic Chapter Outline Large scales in space and time The restless atmosphere A moist thermodynamic heat engine-Basics Large-scale wind patterns Local response to wind-Surface drift Wind stress The inertial response to a wind impulse Balancing forces at the surface Balancing forces sub-surface Large-scale consequences Basin-scale response-The great gyres The wind-driven circulation and vorticity Opposing vorticity tendencies Horizontal pressure gradients and sea surface slopes Gyre circulation and Ekman currents-The combined surface drift Additional influences on surface and near-surface drift Examples of surface drift at basin scale Sargassum seaweed in the Sargasso Sea Subsea volcanic eruptions and pumice rafts Tsunami debris and container spills The fate of plastics in the World Ocean References 4 Western boundary currents and drifting organisms Chapter Outline Mapping and characterizing western boundary currents Local force balance Sea surface slopes Horizontal density gradients Estimating geostrophic currents Basin-scale force balance Conservation of absolute vorticity in the interior of a subtropical gyre Balancing vorticity at the western boundary Vorticity tendencies around a subtropical gyre Leaving the boundary behind Drift through western boundary current systems-Particle trajectories, ensemble statistics, and ecological consequences The enigmatic first year in the life of sea turtles-Finding Nemo in NEMO Tracing the fate and source of the Gulf Stream Separation and retroflection Vertical shear in western boundary currents and vertical motion along trajectories Transports associated with western boundary currents Hydrographic changes along western boundary current trajectories Nutrient streams and wider biogeochemical contexts Temperature-sensitive microbial ecology References 5 Eastern boundary currents, upwelling, and high biological productivity Chapter Outline Mapping and characterizing EBC systems Eastern boundaries in the subtropics-The `Big Four upwelling systems The Leeuwin Current-An exception to the rule in the subtropics Eastern boundaries in subpolar latitudes Ekman dynamics in the presence of a coast Geostrophy in the presence of topography Slope currents Drift along and across eastern boundary current systems-3D water parcel trajectories and the ecological consequences The source of upwelled water, nutrients, and productivity Sources of the European Slope Current and downstream influences on North Sea ecosystems References 6 The tropical oceans, interannual climate variability, and ecosystem adaptation Chapter Outline Mapping and characterizing currents near the Equator The Pacific The Atlantic The Indian Ocean Ekman dynamics near the Equator Tropical variability Planetary waves near the Equator El Niño and the Southern Oscillation Tropical Instability Waves Drift in the tropics-2D water parcel trajectories and some ecological consequences Dispersal of coral spores and connectivity throughout the tropics Re-visiting pumice drift-An eruption in the tropical South Pacific Adaptation of sea turtles to tropical ocean currents The Sargassum Crisis in the Atlantic Tropical ocean circulation and climate variability Recent ENSO variability and associated teleconnections Variable Atlantic hurricane seasons Western Indian Ocean warming and the South Asian Monsoon References 7 From the northern subpolar oceans to the Arctic and its retreating sea ice Chapter Outline The northern cryosphere Sea ice Glacial ice The atmosphere at mid and high latitudes The jet stream The stratospheric polar vortex (SPV) The North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO) Greenland tip jets and intense air-sea interaction Water masses of subpolar and high latitudes Mode waters Intermediate waters Dense waters Ocean circulation at subpolar and high latitudes The subpolar North Atlantic and water mass transformation The Greenland-Iceland-Norwegian Seas The Arctic The deep circulation Variability and long-term change Variability and recent events across the subpolar North Atlantic Greenland mass imbalance and peripheral seas The changing Arctic References 8 From the Southern Ocean to Antarctica and its changing ice shelves Chapter Outline The southern cryosphere Sea ice Glacial ice The atmosphere at southern high latitudes Mid-latitude atmospheric circulation and the Roaring Forties High latitude atmospheric circulation and the Southern Polar Vortex Katabatic winds The Southern Annular Mode Air-sea exchanges of heat and freshwater Water masses of the Southern Ocean and around Antarctica Mode Waters and Intermediate Waters Dense water preconditioning around Antarctica Abyssal and Deep Waters Surface and deep-reaching currents Ekman currents in the Southern Ocean The Antarctic Circumpolar Current (ACC) Fronts, jets, and eddies The subpolar gyres Coastal and slope currents around Antarctica Meridional overturning cells and sensitivity of the 3D circulation to wind forcing The upper limb and CDW upwelling The lower limb and AABW export Sensitivity of the 3D circulation to wind forcing Modelling the Southern Ocean-A brief history and the status quo Applied contexts Microplastics reaching the Southern Ocean and consequences for seabirds Plastics reaching Antarctic waters Ecological pathways to Antarctica Natural and artificial iron fertilization Heat and carbon uptake in the Southern Ocean Interaction of warming ocean with Antarctic ice shelves and global sea level rise 9 Processes and flows in marginal seas Chapter Outline Processes in marginal seas Turbulence and mixing Tides Seasonal stratification Tidal mixing fronts and residual circulation Runoff and freshwater Exchanges Summary of processes Deep or isolated marginal seas The Mediterranean and Black Seas Red Sea and Persian Gulf Japan and Okhotsk Seas The Indonesian Seas Caribbean Sea and Gulf of Mexico Shelf seas Northwest European shelf China Seas Sunda and Sahul shelves Northeast US and east Canadian seaboard Patagonian shelf High-latitude shelf seas Freshwater influences Equatorial Atlantic East Asia Northwest Europe Biological productivity and pollution in marginal seas Primary productivity in shelf seas and at shelf breaks Microplastic drift through coastal and shelf seas References 10 Ocean boundaries, connectivity, and inter-ocean exchanges Chapter Outline Defining an ocean basin Surface connectivity Upper-ocean connectivity and inter-ocean exchanges Fronts as demarcation lines Coherent structures and marine biogeography Re-defining an ocean basin References 11 The global circulation and transformation of water masses Chapter Outline Piecing together a global circulation The near-surface circulation The sub-surface circulation The 3D global circulation Meridional overturning cells, forcing, and energetics Pole-to-pole overturning - The holistic perspective Boundary forcing - The thermohaline perspective Pushing and pulling the MOC - The energetics perspective Global trajectories and pathways of water parcels Re-thinking circulation in property space Surface density fluxes Diapycnal density fluxes The surface water mass transformation rate Interior water mass transformation Linking the circulation and transformation of water masses Surface-forced overturning The global thermohaline circulation in temperature and salinity space References 12 Ocean currents, heat transport, and climate Chapter Outline Meridional heat transport by the AMOC and north European warmth Variability of the large-scale ocean circulation and regional climate Tracing the global overturning in changing property distributions Abrupt climate change in the past-A warning for the future References Epilogue: Looking ahead Unfolding changes in ocean currents Emerging technologies Opportunities and solutions