Ocean Currents PDF

Ocean Currents Ocean Currents “Rivers” of water in the ocean moving in a certain direction ○ Surface and Density currents Why currents are important ○ Transfer heat from the equator to the poles Distributing heat throughout the earth makes it habitable ○ Affec...

Ocean Currents Ocean Currents “Rivers” of water in the ocean moving in a certain direction ○ Surface and Density currents Why currents are important ○ Transfer heat from the equator to the poles Distributing heat throughout the earth makes it habitable ○ Affects weather patterns and and contributes to regions’ climates ○ Transfers nutrients throughout the ocean (higher in cold environments) ○ Cycles gases through the ocean and the atmosphere How do global winds affect ocean currents? Prevailing (global) winds: Earth’s major wind belts Trade winds ○ Flows towards the west ○ 0°-30° N/S Westerlies ○ Flows from the west ○ 30°-60° N/S E W→ Earth’s rotation Global/prevailing winds Prevailing winds influence the formation of ocean currents and the direction they move They affect surface currents only  Noti c direc e the gen tio era the g ns betwe l lob en (oran al winds direc ge) and ti ocea on of the n cur rents Surface Currents Surface currents are controlled by: ○ Prevailing (global) winds Discu ssed ○ Coriolis Effect set of in next notes ○ Continent shapes They can carry warm or cold water horizontally across the ocean’s surface  How do surface currents affect climate? Temperatures of surface currents affect climate on the continents West US: Warm currents = more humid climates Drier (less precip) and cooler Cold currents = drier climates -California current (cold) Ex. Gulf Stream = flows north along east coast of US Southeast US: Humid (more precip) Southeast US is more humid with abundant vegetation and warmer Ex. California current = flows south along west coast of US -Gulf Stream (warm) West coast is more dry with desert regions Density Currents Currents far below the ocean’s surface that are caused by changes in density (i.e. temperature and salinity) Move vertically to carry water between the surface to deeper parts of the ocean ○ Upwelling - often along coastlines, brings nutrient rich (cold) water from depths to ocean surface Compare the map of fisheries in southern California (right image) to upwelling of cold, nutrient rich water along the west coast of the US (left image) Smaller fish rely on these nutrients, so they will stay where there are large amounts of nutrients  Great Ocean Conveyor Belt Surface currents and Density currents combine to form a global “conveyor belt” that transfers heat and nutrients throughout the Earth Scientifically named: Thermohaline circulation ○ Thermo = temperature ○ -haline = salt be c a u se it is this in Named BY changes N DRIVE Estimated that it takes about 1000 years to complete a cycle of the Thermohaline Circulation model. Surface Currents: What you need to know You must know the: Name Do NOT label every current Location on your map, ONLY the 15 Direction you need to know Temperature of each surface current on the next slide. **Quizlet/flashcards can be a good study tool** Surface Currents to know 1. Gulf Stream 9. Kuroshio current 2. Canary (islands) current 10. Peru current 3. Labrador current 11. East Australian current 4. North Atlantic Drift (warm) 12. West Australian current 5. East Greenland current 13. Alaska current 6. Brazil current 14. Antarctic Circumpolar current (cold) 7. Benguela current 15. Norwegian current 8. California current