Vertical temperature change

● Temperature – there are 3 temperature zones in the ocean.

● Surface to 200 meters – warmed by the Sun.● Thermocline: 200 to 800 meters – sharp drop in

temperature● Deep water: 800 meters and below – almost

freezing.● Cold water is more dense than warm water.

Surface water

● Warmest water is located near the Equator due to direct solar radiation.

● Coldest water is located near the poles due to indirect solar radiation.

Surface Currents

● Are caused by wind.● Only affect the top 200 meters of the

ocean.● Are affected by the Coriolis Effect which

causes the currents to curve.● Clockwise in the Northern hemisphere.● Counterclockwise in the Southern hemisphere.

Deep currents

● Are caused by differences in density.● Move across the ocean floor ● Can take 1000 years to travel from the

poles to the Equator

Down welling

● Surface water sinks bringing oxygen to the ocean floor, allowing deep water marine life to exist.

Upwelling

● Wind moves water away from the coast, creating a void. The void pulls cold water up from the deep.

● Brings nutrients up from the ocean floor.

● Many marine creatures.● Fish nurseries.● Upwelling on the coast

of Chile is vital to the survival of anchovies.

Currents and Climate

● Ocean currents cool or warm the air above them, affecting climate.

● Cities at the same latitude may have very different climates because of the ocean currents near them.

Changing currents

● Creates El nino and La nina– El nino is a warmer than usual current which

changes the weather across the US and other countriesLa nina is a cooling of the same current which also causes weather changes.