1. OCEAN CURRENTS

2. OCEAN CIRCULATION  Of the four systems on earth, the hydrosphere is what separates us from the other planets.  Earth’s vast quantities of water make life as we know it possible  About 70% of Earth’s surface is covered in water - most of which is found in the oceans  Of the four systems on earth, the hydrosphere is what separates us from the other planets.  Earth’s vast quantities of water make life as we know it possible  About 70% of Earth’s surface is covered in water - most of which is found in the oceans

3. SURFACE CURRENTS  The ocean is not still, like a pond - it moves in distinct patterns called currents.  Some currents flow nearer to the surface  Surface Currents  These currents are driven by several different forces  Solar radiation  Wind patterns  Coriolis effect  The ocean is not still, like a pond - it moves in distinct patterns called currents.  Some currents flow nearer to the surface  Surface Currents  These currents are driven by several different forces  Solar radiation  Wind patterns  Coriolis effect

4. SOLAR RADIATION  As energy from the sun hits earth, it is dispersed unevenly across the latitudes  This uneven heating causes air to rise and fall over the surface of the earth in distinct patterns  As energy from the sun hits earth, it is dispersed unevenly across the latitudes  This uneven heating causes air to rise and fall over the surface of the earth in distinct patterns

5. SOLAR RADIATION  More direct energy from the sun hits the equator.  This air warms up and rises and is deflected either eastward or westward due to the Coriolis effect  More direct energy from the sun hits the equator.  This air warms up and rises and is deflected either eastward or westward due to the Coriolis effect

7. CORIOLIS EFFECT  The Coriolis Effect is an apparent deflection of an object moving in a rotational motion

8. SURFACE CURRENTS  The way in which the air moves across the surface of the earth, directly influences how surface ocean currents move  Ocean currents develop due to friction between ocean water and the winds that blow across the surface.  Ocean currents move in a pattern consistent with the pattern of winds that blow across the surface of the earth.  The way in which the air moves across the surface of the earth, directly influences how surface ocean currents move  Ocean currents develop due to friction between ocean water and the winds that blow across the surface.  Ocean currents move in a pattern consistent with the pattern of winds that blow across the surface of the earth.

9. Ocean Circulation

11. DEEP WATER CURRENTS  Some currents flow from the bottom of the ocean upwards  Deep water currents  These currents are caused mainly by density driven forces and gravity  Some currents flow from the bottom of the ocean upwards  Deep water currents  These currents are caused mainly by density driven forces and gravity

12. DENSITY  Density is mass per unit volume (D=M/V)  In Seawater density depends on two factors  Temperature of the water  Volume  Salinity of the water  Mass  Changes in density cause water to rise and fall  Less dense  water rises  More dense  water falls  These changes are what drives deep water current  Density is mass per unit volume (D=M/V)  In Seawater density depends on two factors  Temperature of the water  Volume  Salinity of the water  Mass  Changes in density cause water to rise and fall  Less dense  water rises  More dense  water falls  These changes are what drives deep water current

13. SALINITY  An increase in dissolved substances increases the density  Salinity tends to be highest at the poles and near the equator.  Near the poles, water is trapped in glaciers - increasing the amount of salt in the water  Near the equator, evaporation is high - increasing the amount of salt in the water  An increase in dissolved substances increases the density  Salinity tends to be highest at the poles and near the equator.  Near the poles, water is trapped in glaciers - increasing the amount of salt in the water  Near the equator, evaporation is high - increasing the amount of salt in the water

14. TEMPERATURE  A decrease in temperature causes an increase in density - the molecules are moving slower and packed closer together  Density is greatest in polar regions - high salinity and low temperature  Temperature is the most important factor in density  A decrease in temperature causes an increase in density - the molecules are moving slower and packed closer together  Density is greatest in polar regions - high salinity and low temperature  Temperature is the most important factor in density

15. THERMOCLINE  The layer of ocean water between 330m - 1000m, where there is a rapid change of temperature with depth.  The thermocline is essentially non-existent in high latitudes (polar regions)  The layer of ocean water between 330m - 1000m, where there is a rapid change of temperature with depth.  The thermocline is essentially non-existent in high latitudes (polar regions)

16. DEEP OCEAN CURRENTS  Density Currents  Dense water sinks and slowly spreads out across the bottom of the ocean  Most deep ocean currents begin in high latitudes (poles) where temperature is low and salinity is high.  As the water becomes dense, it sinks and spreads out over the floor of the ocean  Density Currents  Dense water sinks and slowly spreads out across the bottom of the ocean  Most deep ocean currents begin in high latitudes (poles) where temperature is low and salinity is high.  As the water becomes dense, it sinks and spreads out over the floor of the ocean

17. DEEP OCEAN CURRENTS  Evaporation  Deep water currents can also exist as a result of evaporation  Evaporation of surface waters increases salinity and thus the density of the water.  This is evident in the Mediterranean Sea.  A dense water mass forms on the surface, sinks and flows into the Atlantic  Evaporation  Deep water currents can also exist as a result of evaporation  Evaporation of surface waters increases salinity and thus the density of the water.  This is evident in the Mediterranean Sea.  A dense water mass forms on the surface, sinks and flows into the Atlantic

18. CONVEYER BELT

19. CLIMATE  The conveyer belt system of currents moves around the globe, influencing global climate

20. CLIMATE  Heat Transfer  Currents transfer heat as they move across the ocean  When currents from low-latitude regions move to higher regions, they move warmer water to cooler areas on earth.  Heat Transfer  Currents transfer heat as they move across the ocean  When currents from low-latitude regions move to higher regions, they move warmer water to cooler areas on earth.

21. Gulf Stream  The Gulf Stream is a warm water current that brings warm water from the equator up to the North Atlantic.  This allows regions in northwestern Europe, like Great Britian, to experience milder winters - despite their latitude  The Gulf Stream is a warm water current that brings warm water from the equator up to the North Atlantic.  This allows regions in northwestern Europe, like Great Britian, to experience milder winters - despite their latitude

22. CLIMATE  Warm water currents tend to create milder climates in normally cooler regions - Great Britian  Cool water currents tend to create cooler than normal climates - California coast is an example. - Polar currents bring cool waters which create cooler climates, including extensive fox and cool ocean waters.