LESSON 3: THE OCEAN AND THE CLIMATE
WHAT MIGHT HAPPEN IF OCEAN CURRENTS ARE
DISRUPTED?
Understanding Goals 
Water in the ocean moves in currents throughout the world. The wind helps the water move along. 
The ocean absorbs heat from the sun and the ocean currents release this heat to the surrounding air and nearby land as they move across the planet. 
The ocean’s currents help spread and distribute heat throughout the earth. National Science Standards Physical Science K‐4 Properties of Objects and Materials Position and Motions of Objects Personal and Social Perspectives K‐4 Types of Resources (the ocean as a resource of resources) Note Students do not necessarily need to understand density for this lesson; however, if they have learned about density or are learning about it, it would be good to discuss the role of density in ocean currents, since the density differences between water in the ocean drive the flow of deep‐ocean currents. (Saline, cold water is denser than fresh, warm water and so the former sinks, which explains how the ocean water sinks near the Arctic. As the ocean currents move towards the North Pole the water gets cooler and sinks deep into the ocean. This deep‐water, cold‐water ocean moves across the ocean floor, towards the equator and eventually rises to the surface as the water gets warmer. So, the currents move in a circular motion like a conveyor belt.) The goal of this lesson is not to build students’ understanding of HOW ocean currents work, or WHY cold, salty water sinks and warm, fresh water floats, or what factors contribute to the ocean currents. Rather, the goal is to begin developing students’ understanding of the role that ocean currents play in maintaining a habitable climate. Healthy Ocean, Healthy Humans
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Vocabulary climate, ocean currents Advance Preparation Be ready to play YouTube user zackrz7’s video at http://www.youtube.com/watch?v=7ahSxpIh0M video at or videos/DVDs/tapes of sounds of waves. Materials None Lesson Plan Part 1A (5 min) If the previous lesson (Lesson 2) was not taught, do part 1B instead. Listen to the sounds of waves. Then discuss homework questions from previous lesson. Part 1B (10 min) Have students watch the ocean and listen to its waves for a few minutes. Gather reactions. How do they feel after listening to the waves and watching the ocean? Part 2 (10 min) “Starting from today, we’re going to start exploring what the ocean does and why it’s important. Today, we’re going to focus on the relationship between the ocean and climate.” Ask for definition of climate. [Climate is weather patterns over a long period of time, thousands of years; weather is the daily changes in temperature and amount of sun, clouds, rain.] Ask: “How do you think the ocean helps keep the Earth at the right temperature or right climate?” Have students think pair‐share for a few minutes. Then gather ideas from the whole class. Ask: Why is it important for the earth’s climate to be just right? What would happen if it was too hot? Too cold? Think about the other planets. Part 3 (25‐30 min) In a minute we’re going to do a demonstration that will show how the ocean helps the earth’s climate from being too hot or too cold. Ask: “Does the ocean water remain still? Or does it move all around the planet?” Have students raise hands for one of the two. Healthy Ocean, Healthy Humans
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Reveal that ocean water moves and that this movement is very important for our climate. Also explain that the ocean absorbs heat from the sun, and that as the ocean water moves, it carries heat with it. “We’re going to do a demonstration of how the ocean moves and why it’s important for our climate.” Have students stand in a large circle in the classroom, and then have them face clockwise. Establish one end of the room as “North” and the other end as the equator. Explain that they will be simulating an ocean current for the Northern hemisphere. Explain that students represent ocean water droplets. Ask students where they expect water to be the warmest and the coolest. [warmest near the equator, coolest near the North pole.] Explain that the as the warm water moves, it releases heat into the atmosphere and warms up nearby land. The water cools down as it reaches near the pole and heads back down towards the equator. The water becomes warmer, and begins the journey back to the Pole again. Each water droplet pushes the water droplet before it and is pushed by the water droplet behind it. Each student needs to maintain the same distance apart from the student in front and behind. Have students walk around the classroom clockwise for a minute or so. Then, ask one student to stop moving while others try to keep on moving at the normal speed. They should see that immediately, the whole movement becomes stuck when there is a break in the continuous motion. It’s kind of like an accident that then causes a traffic jam. Thus, the current stops moving. Ask: “What does this mean? What would happen if the ocean water stopped moving?” Have students think on their own for a minute, and then ask them to share their answers. Make sure that students understand how ocean currents help distribute heat across the world, and prevent the areas near the Arctic to be not too cold and the equator to be not too hot. If the current stopped, the equator area would probably get much hotter, and the Arctic regions, even colder. Reflection / Homework Questions 1 Why are ocean currents important? What do they do? 2
What would happen if ocean water stopped moving? Follow this format to answer this question: If the ocean water stopped moving, then_________________ because _______________. 3
What do you think might happen to the earth’s climate if the ocean completely disappears? Follow this format when you answer this question: If the ocean disappeared, then the earth’s climate might _______________ because _______________. Healthy Ocean, Healthy Humans
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