The TEKS Know that climatic interactions exist among Earth, ocean, and weather systems. • 8.10 (A) recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents; ENGAGE Ocean Currents What causes the movement of air and water throughout the Earth? EXPLORE 1) Fill your container with tap water. 2) Carefully place an ice cube at each end of the baking dish. 3) Observe what happens. 4) Record your observation on your lab sheet. EXPLAIN 1) What did the ice cubes represent? 2) Why were they placed at the far end of your container? 3) What did you observe? TIME FOR A FOLDABLE CONVECTION Transfer of heat by the movement of warmer, less dense (air or liquid) rising and cooler, denser (air or liquid) sinking CONVECTION CONVECTION CONVECTION Moves air in the atmosphere! Moving Air = Winds Convection in the atmosphere is the main cause of the wind. Where does the Energy for Convection come from on Earth? THE SUN!!! CONVECTION CONVECTION causes deep ocean currents! CONVECTION Wind over the shore changes direction because of EARTH’S UNEVEN WARMING & COOLING! Hot Air is Less Dense! Atmospheric Movement MOSTLY CAUSED BY: - Temperature differences - Pressure differences - Coriolis Effect (due to Earth’s rotation) The Coriolis effect • The Coriolis effect – Is a result of Earth’s rotation – Causes moving objects to follow curved paths: • In Northern Hemisphere, curvature is to right • In Southern Hemisphere, curvature is to left – Changes with latitude: • No Coriolis effect at Equator • Maximum Coriolis effect at poles The Coriolis effect on Earth • As Earth rotates, different latitudes travel at different speeds • The change in speed with latitude causes the Coriolis effect Figure 6-9a Role of the Ocean • Slowly absorbs and slowly releases heat energy helping keep Earth’s temperatures relatively stable • Oceans heat or cool the air above them and transport heat around the globe in currents. • Hurricanes form over warm ocean water, drawing their energy from the water’s heat. Ocean Currents Currents • large scale water movements – occur everywhere in ocean – both surface and deep • 2 main types: surface currents (10%) and deep sea currents (90%) – surface currents are primarily wind driven – deep currents are density driven – other forces affecting currents Coriolis effect friction gravity thermal expansion geologic shape of ocean basin ELABORATE 1) Use the pipette to carefully put several drops of red hot water at the bottom of the container. 2) Remove the pipette and watch what happens to the red water. Why is it important to study ocean currents? How do plants, animals, and humans use ocean currents? Ten Bizarre Things That Washed Up On Shore EVALUATION 1) Convection currents, which affect weather and climate, are created by... A. slow, constant tectonic movement. B. erosion of ocean beaches. C. mining of the seafloor. D. the uneven heating of the Earth. 1. Convection currents, which affect weather and climate, are created by... Answer: D. the uneven heating of the Earth. 2) Water is cooler near the poles and warmer near the equator. Movement of cooler and warmer water from these regions moderates the global climate. Which of the following describes the movement of water between the poles and the equator? A. tides B. ocean currents C. evaporation D. gravity 2. Water is cooler near the poles and warmer near the equator. Movement of cooler and warmer water from these regions moderates the global climate. Which of the following describes the movement of water between the poles and the equator? Answer: B. ocean currents 3. Surface ocean currents are primarily formed by _______. A. winds B. tides C. aquatic organisms D. underwater volcanoes 3. Surface ocean currents are primarily formed by _______. A. wind 4. Which of the following is NOT true: A. colder, denser water at the poles sinks below warmer water. B. colder, denser water at the poles rises above warmer water. C. warmer, less dense water at the equator rises above colder water. D. saltier, denser water sinks below fresh, less dense water. 4. Which of the following is NOT true: B. colder, denser water at the poles rises above warmer water. 5. What does the Coriolis Effect explain? A. why it is hard to catch baseballs. B. why surface winds or currents turn in one direction or another. C. how volcanoes are formed. D. why salt water is denser than fresh water. 5. What does the Coriolis Effect explain? B. why surface winds or currents turn in one direction or another. Lost at Sea Duckie Progress •January 1992 - shipwrecked in the Pacific Ocean, off the coast of China •November 1992 - half had drifted north to the Bering Sea and Alaska; the other half went south to Indonesia and Australia •1995 to 2000 - spent five years in the Arctic ice floes, slowly working their way through the glaciers •2001 - the duckies bobbed over the place where the Titanic had sunk •2003 - they were predicted to begin washing up onshore in New England, but only one was spotted in Maine •2007 - a couple duckies and frogs were found on the beaches of Scotland and southwest England.