For Class Today Modified Cornell Notes on section 16.1 (pg. 448-453) **Follow the guide in your ISN and previous notes for help** Heading: How does ocean water circulate? Left hand side categories: Ocean currents, surface currents, gyres, currents & climate, upwelling, deep ocean circulation Write a 1-2 sentence summary at the bottom of your notes Use the map on pg. 449 to identify and label the gyres and currents on your map
Currents A current is a movement of water that follows a regular pattern Surface Current Horizontal, stream like movements of water that occur at the surface of the ocean. Gulf Stream is 100 miles wide; 2,000 feet deep with a max speed of 5mph
What three factors control the flow of surface currents? A. Global winds B. Coriolis Effect C. Continental deflections
Coriolis Effect As Earth spins, anything moving in a straight line from North to South will be deflected sideways. In the Northern Hemisphere, winds, water, and other fluids will be deflected to the right at a 90 o angle or clockwise In the Southern Hemisphere, everything will be deflected to the left at a 90 o angle or counterclockwise
Coriolis Effect
Coriolis Effect Coriolis Effect in Space: Video 2 Try this flight simulator: http://www.montereyinstitute.org/noaa/le sson08/l8ex1.htm
Factors that Influence Surface Currents: Continental Deflection
Ocean Currents Exploration Use your surface current map (or pg. 449) List the ocean, hemisphere and gyre name For each current Flow direction (north, south, east or west) Temperature (warm or cold) Speed of Current cross out: we are not doing this section! Answer the analysis questions - #6 on back
Ocean Currents Exploration Which surface current is off the coast of the Jersey shore? Is this a warm current or a cold current? What gyre is it part of? What are the other currents in this gyre?
Nike Shoes, Rubber Ducks and Ocean Currents
Rubber Ducks, Nike Shoes, and Ocean Currents Plot locations for Nike Shoes and determine the most logical route taken by the shoes Plot locations for rubber ducks and determine the most logical route taken by the shoes Answer analysis questions on back
Surface Currents Type of Current Density Which side of the ocean basin? Where does this current originate? Where does this current move to? Warm Surface Current Cold Surface Current
Deep Ocean Currents Caused by differences in density (temperature & salinity) Move along ocean bottom from poles to equator Average speed: 8 miles/day Polar Creep
Ocean Conveyor Currents Constantly moving system of deep-ocean circulation driven by temperature and salinity The Great Ocean Conveyor transports cold water from the poles around the globe Water warms and rises at the equator
Upwelling Movement of deep, cold, nutrient dense water to the surface
Upwelling 1. Winds move warm surface water away 2. Cold deep water moves up and replaces it 3. Brings nutrients and minerals to the surface which feed plankton
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What is El Nino? El Niño is a phenomenon that occurs every few 2-7 years during which the East Pacific Ocean increases in temperature along the equator. December 1993 (normal conditions) December 1997 (El Niño conditions)
El Nino Weak Trade Winds Warm air stays near South America causing the temperatures to rise Stops upwellings along South America, no nutrients, disrupting the food chain.
Effects on the Climate and Atmosphere Normal conditions During El Niño Coastal upwelling near S. America shuts down and the water warms up. 1) How does this affect fish populations? 2) How does this affect the rest of the world?
El Niño Summary Causes Pacific currents slow down along equator. Upwelling shuts down warmer water at surface Weather Effects Droughts in Australia and Indonesia Heavy rains along the west coast of the Americas. Milder winters in the US.