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Oceanography Ocean Currents. Chapter 24.1 and 24.2. There are 2 types of ocean currents Surface Currents Density Currents ( currents under the surface). Surface Currents. Wind is the driving force behind surface currents **This should look REALLY familiar!.
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OceanographyOcean Currents Chapter 24.1 and 24.2
There are 2 types of ocean currents • Surface Currents • Density Currents ( currents under the surface)
Surface Currents • Wind is the driving force behind surface currents **This should look REALLY familiar! Click here to see how wind and surface currents are related!
Layers of the Ocean SURFACE CURRENTS Mixed Layer (2%) Temp Change Deep waters Density Currents
Surface Currents • In the Northern Hemisphere, travel clockwise • In the Southern Hemisphere, travel counterclockwise • Like winds, this is due to the Coriolis Effect
Global Surface Currents p.532
Warm Ocean Currents • Travel __________ the equator. • This transfers ______ from the _________to the _______ • Example: • Creates the Sargasso Sea AWAY FROM ENERGY EQUATOR POLES GULF STREAM
Cold Ocean Currents CANARY CURRENT (AFRICA) CALIFORNIA CURRENT
Cold Ocean Currents TOWARDS • Travel __________ the equator. • Example: California Current: travels down the WEST side of the U.S. Canary Current: travels down the WEST side of AFRICA
El Nino vs. Normal Conditions ~ Normal Conditions:
El Nino vs. Normal Conditions ~ El Nino:
Subsurface Currents • The driving force behind a subsurface current is _________________. • They are also known as ____________________________. • If water becomes denser it will ___________. • If it becomes less dense it will ___________. density density currents sink rise
What are the ways (liquid)water becomes denser? Cooling – molecules closer together Evaporation – leaves salt behind Freezing – leaves salt behind
Antarctic Bottom Water is created at the poles where freezing and cooling increase the salinity and the density of the water.
Mediterranean Sea (p538) • This density current is caused by evaporation instead of freezing and cooling. Close to 30° latitude = Dry Air
Upwelling • As wind drives water away from the coast, deep cold waters replace it • This brings CO2 to the surface for phytoplankton to feed on Click the picture to see the animation!
Ocean Temperature Mixed Layer • Wind and waves mix heat evenly • Absorbs almost all of the sun’s light • Maximum depth usually 100 meters Thermocline • Area where temperature drops rapidly • Maximum depth usually 1000 meters Deep Water • Very cold water moving from poles to equator • Most dense water • Found beneath other ocean water in almost all ocean locations