Ocean CurrentsOcean Currents

Two Types of CurrentsTwo Types of Currents

Density Driven (deep water) CurrentsDensity Driven (deep water) Currents Wind Driven (surface) CurrentsWind Driven (surface) Currents

Density Driven CurrentsDensity Driven Currents Move water vertically through the oceanMove water vertically through the ocean Density differences cause deep water Density differences cause deep water

currentscurrents Dense water sinks at the polesDense water sinks at the poles Less dense water rises Less dense water rises

at the equatorat the equator This process creates This process creates

circulation throughout circulation throughout

the oceans of the worldthe oceans of the world

Surface CurrentsSurface Currents

Winds are primary energy source for Winds are primary energy source for surface currents.surface currents. Winds blow across the ocean surfaceWinds blow across the ocean surface friction between the wind and the ocean friction between the wind and the ocean

surface drags the water alongsurface drags the water along

Which way does the water Which way does the water flow?flow?

Rotation of the earth changes path of Rotation of the earth changes path of air and water (Coriolis Effect)air and water (Coriolis Effect)

Water flows to the right (clockwise) Water flows to the right (clockwise) in Northern Hemispherein Northern Hemisphere

Northern Pacific Surface Northern Pacific Surface CurrentsCurrents

EquatorNorth Equatorial Current

Kuroshio Current

California Current

South Equatorial Current

East Australian Current

West Wind Drift

Peru Current

Global Surface CurrentsGlobal Surface Currents

Most ocean currents have a dramatic Most ocean currents have a dramatic impact on local weather and impact on local weather and continental climate patternscontinental climate patterns

Ex: Mediterranean climate zonesEx: Mediterranean climate zones

Surface Currents in the USSurface Currents in the US

San Francisco Washington,

DC

The Gulf Stream is warm and comes from the equator/ Gulf of Mexico

The California Current is cold and comes from Alaska

What is a gyre?What is a gyre?

A roughly circular pattern of ocean A roughly circular pattern of ocean surfacesurface currents currents

Caused by the Coriolis EffectCaused by the Coriolis Effect

North Pacific GyreNorth Pacific Gyre

Equator

Why are gyres/ currents Why are gyres/ currents important?important?

Warm currents move heat from the Warm currents move heat from the equator to middle and high latitudesequator to middle and high latitudes

Gyres influence air temperature, Gyres influence air temperature, weather and climate of every weather and climate of every continentcontinent