La Terre possède un grand océan avec de nombreuses caractéristiques.

• Basins include the seafloor and geological features.
• their size, shape, and features vary with lithospheric movement.

• The ocean is large but finite in space and resources.

• Seven major plates and many smaller plates form the constantly recycled lithosphere.

• Spreading ridges form new oceanic crust.
• subduction recycles older crust into the mantle.
• Subducted oceanic lithosphere returns to the mantle.

• Convergence and divergence determine seafloor features including islands, seamounts, trenches, ridges, and rift valleys.
• Plate boundaries create characteristic ridges, trenches, rifts and volcanic landforms.

• Seafloor change can be rapid during earthquakes or eruptions, or occur over millions of years through spreading.

• Tectonic activity continually creates and destroys features such as islands.

• Salinity, conductivity, freezing point, density, and pH affect ocean biological and physical characteristics.

• Salinity measures salts, including magnesium, sodium, calcium, chlorine, and potassium.
• salinity and temperature determine density.

Notes sur l’adaptation (en anglais)

Use chloride rather than elemental chlorine for seawater ions, and land ice for melt that adds ocean water. These are scientific wording clarifications, not additional CFD branches.

• Ocean pH is slightly basic and is affected by dissolved carbonate ions.

• pH balance matters to marine ecosystems including coral reefs and to the ocean’s response to additional atmospheric carbon dioxide.
• Carbonate buffering affects pH and further atmospheric carbon uptake; coral reefs are an affected ecosystem.

Notes sur l’adaptation (en anglais)

Restore the link between carbonate buffering, lower pH and future carbon uptake capacity.

• www.pmel.noaa.gov

• Ocean water is continually moving.

• Wind-driven and density-driven currents circulate ocean water.

• Coriolis, prevailing winds, continents, and other currents direct wind-driven surface currents into gyres.

• Surface currents influence subsurface currents through Ekman forces.

• The diagram gives opposite gyre rotation by hemisphere and links colder water to continental west coasts and warmer water to east coasts.

Notes sur l’adaptation (en anglais)

Qualify rotation and boundary-current directions as major subtropical gyres; the unqualified statement does not describe all gyres.

• sos.noaa.gov

• Prevailing winds and Coriolis can move surface water offshore, replaced by nutrient-rich water from below.

• Upwelling supports high productivity, especially along continental west coasts and around Antarctica.

• Temperature and salinity variations drive thermohaline circulation and density layering.

• Saltier or colder water is denser.
• denser water tends to sink and less dense water to rise.

• Densest layers flow near the seafloor with less dense water stratified above.

• Water moving from equatorial regions toward the poles cools, becomes denser, and can sink.

• The thermohaline conveyor-belt model links water movement within and among ocean basins.
• Temperature and salinity influence density-driven thermohaline circulation.

• Interbasin mixing transports heat, solids, gases, dissolved substances, and organisms.

• Circulation changes affect climate and ecosystems.

• The water cycle exchanges water between ocean and atmosphere.

• Waves transfer energy over long distances with little horizontal movement of water.

• Wind friction produces waves.
• earthquakes can generate tsunamis.

• Waves break when too steep in deep water or large relative to depth near shore.
• Deep-water steepness and wave height relative to shallow-water depth can cause breaking.

• Tides are periodic rises and falls of surface water level.

• Solar and lunar gravity and Earth’s rotation produce tides.

• Tides vary cyclically with the relative positions of Moon, Sun, and Earth.

• Sea level is the average height of the ocean relative to land.

• Sea level differs between places and changes over time.

• Atmospheric pressure and prevailing winds affect regional sea level.

• Sea-surface height differences help set currents in motion.

• Lithospheric movement changes basin volume and land height.

• Temperature changes affect ice growth or melt and seawater expansion or contraction.

Notes sur l’adaptation (en anglais)

Use chloride rather than elemental chlorine for seawater ions, and land ice for melt that adds ocean water. These are scientific wording clarifications, not additional CFD branches.

• Human effects on global climate affect sea level.