ocean currents - weebly€¦ · ocean currents and climate warm water from the equator flows to...
Post on 14-Jul-2020
3 Views
Preview:
TRANSCRIPT
12/3/14
1
Ocean Currents
Surface Circulation
Two types of Ocean circulation:
Surface and Deep
Surface currents are the horizontal movement of water in the ocean’s surface
What causes the water in the oceans to flow?
The friction between wind and the water’s surface creates currents
12/3/14
2
Gyres
Large whirls of water within an ocean basin
5 main gyres: North and South Pacific Gyre, North and South Atlantic Gyre, and Indian Ocean Gyre
Gyres are caused by the Coriolis Effect
Earth’s rotation causes currents to flow away from their original course
In the Northern Hemisphere water flows clockwise
In the Southern Hemisphere water flows counter-clockwise
12/3/14
3
12/3/14
4
Upwelling
Winds also cause vertical water movements called upwelling
Brings colder water from depths of 50 to 300 meters to the surface
Water from below the surface has more nutrients and thus allows a spike in life where upwelling occurs
12/3/14
5
Ocean Currents and Climate
Warm water from the equator flows to higher latitudes
Cold water from the poles flows to lower latitudes
Earth’s heat is more evenly distributed
How does this flow of water affect the climate of San Francisco?
Deep Ocean Circulation
Density Currents
Vertical currents of ocean water that result from density differences in water masses
An increase in density is caused by a decrease in temperature or an increase in salinity
What are the ways that salinity increases?
evaporation and formation of sea ice
12/3/14
6
Global Conveyor Belt
Once the water becomes denser through an increase in salinity and decrease in temperature the water mass sinks
At depths below 300 meters, wind does not create currents
What causes the deep water masses to flow?
pressure from the new water masses sinking and pushing on old water masses
It takes about 1000 years for water masses to complete the entire conveyor belt
top related