Currents of the OceanCurrents of the Ocean

Two main sections of Two main sections of ocean waterocean water

•surface layer surface layer •the deep watersthe deep waters

surface layersurface layerlayer at the top of the oceanlayer at the top of the oceanwell mixed by waves, tides, and weather well mixed by waves, tides, and weather

events like rain or a hurricane. events like rain or a hurricane. sits on top of the deep water because sits on top of the deep water because

the surface layer is less dense the surface layer is less dense depth is typically a couple hundred depth is typically a couple hundred

meters meters

The The pycnoclinepycnocline (meaning rapid (meaning rapid change of density) change of density)

•separates the surface layer of separates the surface layer of the ocean from the deep ocean the ocean from the deep ocean

•Deep ocean water has a Deep ocean water has a temperature of about 3 degrees temperature of about 3 degrees Celsius Celsius

•a salinity measuring about 34-35 a salinity measuring about 34-35 psupsu

The Deep Waters The Deep Waters

• most of the water in the ocean (90% most of the water in the ocean (90% by volume) is actually found below by volume) is actually found below the surface layer the surface layer

• surface water that sinks in the North surface water that sinks in the North Atlantic Ocean Atlantic Ocean

• Here water becomes very cold and Here water becomes very cold and very saltyvery salty

A schematic showing the ocean "conveyor belt", where surface waters sink, enter deep water circulation, then resurface after slowly flowing through the deep ocean.

Currents Currents

•Surface water movement takes Surface water movement takes place in the form of currents. place in the form of currents.

•move ocean water horizontally move ocean water horizontally •driven mainly by the driven mainly by the windwind •Other forces such as Other forces such as the the CoriolisCoriolis

effect effect and the location of land and the location of land masses do affect surface current masses do affect surface current patternspatterns

Low and high pressure circulations are reversed in opposite hemispheres

The Earth's spin causes the wind to curve. This is called the Coriolis Effect.

CurrentsCurrents

•circulation of water helps circulation of water helps spread energy from spread energy from the Sunthe Sun

•The Sun warms water at the The Sun warms water at the equator and then water and equator and then water and heat are transported to heat are transported to higher latitudes.higher latitudes.

Major ocean currents of the Major ocean currents of the world world

•North & South Equatorial Current North & South Equatorial Current

•Equatorial Counter Current Equatorial Counter Current

•North Atlantic Drift North Atlantic Drift

•Gulf Stream Gulf Stream

•Kuroshio Current (off of Japan) Kuroshio Current (off of Japan)

•Antarctic Circumpolar Current Antarctic Circumpolar Current

•East Australian current East Australian current

UpwellingUpwelling

• Upwelling is a term used to denote water that Upwelling is a term used to denote water that rises to the ocean's surface from depth. It is rises to the ocean's surface from depth. It is caused by wind patterns, and is beneficial caused by wind patterns, and is beneficial because the cold, deep water contains because the cold, deep water contains nutrients and dissolved gases, that with nutrients and dissolved gases, that with sunlight, create favorable conditions in which sunlight, create favorable conditions in which phytoplankton can photosynthesize. phytoplankton can photosynthesize. Phytoplankton are the base of oceanic food Phytoplankton are the base of oceanic food webs; therefore, areas of upwelling are webs; therefore, areas of upwelling are important ecologically and economically. important ecologically and economically.