Generate Your Own Ocean Currents!2
Students construct a model ocean that they will blow “wind” over. They document their observations and generalize what they observed to understand the relationship between wind and ocean surface currents.
Suggested Grade Range: 6-8
Approximate Time: 1 hour
Relevant National Content Standards:
Next Generation Science Standards Middle School: Earth’s Systems MS-ESS2-6. Develop and use a model to describe how unequal heating and rotation of the Earth cause patterns of atmospheric and oceanic circulation that determine regional climates. [Clarification Statement: Emphasis is on how patterns vary by latitude, altitude, and geographic land distribution. Emphasis of atmospheric circulation is on the sunlight-driven latitudinal banding, the Coriolis effect, and resulting prevailing winds; emphasis of ocean circulation is on the transfer of heat by the global ocean convection cycle, which is constrained by the Coriolis effect and the outlines of continents. Examples of models can be diagrams, maps and globes, or digital representations.] [Assessment Boundary: Assessment does not include the dynamics of the Coriolis effect.]
Science and Engineering Practices: Developing and using Models Modeling in 6–8 builds on K–5 experiences and progresses to developing, using, and revising models to describe, test, and predict more abstract phenomena and design systems. • Develop and use a model to describe phenomena.
Disciplinary Core Ideas: ESS2.D Weather and Climate Weather and climate are influenced by interactions involving sunlight, the ocean, the atmosphere, ice, landforms, and living things. These interactions vary with latitude, altitude, and local and regional geography, all of which can affect oceanic and atmospheric flow patterns.
Crosscutting Concepts: Systems and System Models Models can be used to represent systems and their interactions—such as inputs, processes and outputs—and energy, matter, and information flows within systems.
Lesson Content Objectives: • Construct a model of the ocean with islands • Observe and document how wind driven currents move water and interact with landmasses
2 An early version of this lesson was adapted and field-tested by Breanne Koontz, a participant in the California State University, Long Beach Foundational Level Mathematics/General Science Credential Program STEM Activities for Middle and High School Students 1
Materials Needed: • One clear, shallow baking dish or plastic tray or tub for each group • Water • Black pepper • Cereal bowls • An assortment of irregularly shaped waterproof objects to submerge • Towels • Activity sheets for each student
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Summary of Lesson Sequence • Introduce the lesson through a whole class discussion. • Provide students with the activity sheets and materials they will need to create a model ocean. • Check for students’ understanding by asking the key questions provided while they are experimenting with their model. • After working with their model, allow students to generalize their observations by explaining the relationship between wind and ocean surface currents using the activity sheets provided. • To close the lesson, have students share their findings in a whole class discussion.
Assumed Prior Knowledge
Prior to this lesson students should know that currents are flows of gas, water, or air and that heat from the sun creates convection currents that cause wind to blow.
Classroom Set Up
Students should work in groups of 4-5 students.
Lesson Description
Introduction Lead students in a whole class discussion about the movement of debris from Japan after the March 2011 earthquake and tsunami. Inform students that debris traveled thousands of miles and reached the California coast. Photographs, maps, news stories and videos are available online to share with students at http://news.nationalgeographic.com/news/2011/03/110311-tsunami-facts- japan-earthquake-hawaii. Ask students:
What do you think caused the debris to travel across the Pacific?
How long do you think it took for debris to reach California?
What natural forces might have acted on the debris in the ocean?
Inform students that the first confirmed piece of debris found in California after the disaster was a small fishing boat found in Crescent City on April 7, 2013. Remind students that ocean currents are caused by wind and ask:
Can you explain what causes convection currents to move air, causing wind?
Remind students that warmth from the sun causes temperature differences on the surface of the earth and in the atmosphere. The warm, less dense air moves up, then cools and becomes less dense and moves back down.
Today we will observe how wind that blows across the ocean creates ocean currents and how these currents interact with landmasses.
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Input and Model Demonstrate how to build a model ocean for students using a shallow tray or tub filled partially with water. Show how they will use a deep bowl to represent an island. Explain that they will also submerge irregular shaped objects and observe currents passing over them.
Guide Students Through Their Practice Provide students with instructions for creating their model ocean. They should work in groups of four or five. They will make four observations:
Carefully fill your clear tray or tub with water. Do not fill it completely. Let the water settle.
Observation 1. Sprinkle some pepper at one end of the tray or tub and gently blow across the tray or tub in a single direction. Observe, describe, and sketch what you see happening at the surface of the water and along the bottom of the tray or tub.
Sprinkle pepper in front of the island
Blow the pepper in one direction
Observation 2 (see above). Gently place your deep bowl upside down in the center of the tray or tub. The bowl should stick out of the water. If it does not stick out, then remove some of the water from the tray or tub, and try again. This is your island.
Sprinkle some pepper in front of the island and gently blow across the tray tub. Observe, describe, and sketch what you see happening to the pepper in front and in back of the island.
Remove the deep bowl and use a paper towel to remove the pepper that is floating on the surface of the water so that you have a clear ocean again.
Observation 3. Select a few irregularly shaped objects to submerge and repeat the procedure, observing and recording your observations.
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Check for Understanding Check for students’ understanding while they are experimenting by asking the following key questions.
For Observation 1:
Are your sketches different from other teams? If so, how are they different?
What happens as the water moves away from the source of wind?
For Observation 2:
What effect does the island have on the current?
Is the current stronger in front of or behind the island? How can you tell?
For Observation 3:
How is the current different with odd shaped objects? Can you predict how the pepper will move across the water when it passes above a submerged object? Explain.
Independent Practice After students have had the opportunity to make all three observations, have them clean up their workstations and write their conclusions on their activity sheets. They may work independently.
Closure To close the lesson, have students share their results in a whole group discussion. Explain that ocean currents affect the distribution of ocean plants and animals as well as the routes that ships take. Ask students to share their experiences or knowledge of the affect of ocean currents.
Suggestions for Differentiation and Extension
• If some students struggle to draw what they are seeing in the tubs, assist them by drawing a picture on the board for the first observation. • Provide students with a topological map of Long Beach’s coastline and have them use the global wind patterns map to predict what the resulting local ocean currents would be (see Map A). Have them use colored pencils to draw the currents. They can research more at Southern California Coastal Ocean Observing System. (http://www.sccoos.org) • Allow students to research and report on “Kelp Watch 2014”, a project led by researchers at CSU Long Beach and UC Berkley to determine whether there is ocean-borne radiation caused by the Fukushima nuclear power plant disaster. (http://kelpwatch.berkeley.edu/)
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Name ______
Generate Your Own Ocean Currents! I. Record your observations by drawing sketches and answering the questions in the table below:
Observation 1 Draw: Sketch your model ocean Answer: Your model showing the direction of the wind Where do the currents move most rapidly? and the movement of the black ocean. pepper.
Observation 2 Draw: Answer: Your model What effect does the island have on the current? ocean with an island. Is the current stronger in front or behind the island? How can you tell?
Observation 3 Draw: Answer: Your model Are the currents more or less complex with the odd- shaped objects? Explain. ocean with an irregularly shaped ocean floor.
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II. Extend your observations to the real world effect of winds on ocean currents. Use the maps to answer the questions on the following page.
Map A shows global wind patterns. Map B shows wind-driven surface ocean currents.
A
B
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1. Compare the wind patterns to the ocean current patterns. Do the patterns in Map A and Map B look similar?
2. Identify areas where the maps show similar patterns and explain why you think they are similar.
3. Identify areas where the maps show different patterns and explain why you think they are different.
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Name ______Our Local Surface Ocean Currents The global wind pattern map below shows the general wind directions during January.
Use the map of global wind patterns to draw what you predict our local surface ocean currents may be in January (how will the surface currents interact with landmasses?):
Long Beach
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