Lesson 4: Surface Currents

Grade Level: 8

Subject(s): Science and Social studies

Learner Outcomes: The student will:

1. construct a model of the North Atlantic
2. replicate the surface winds from the Arctic Circle to the tropic of Capricorn
3. Identify several coastal countries on their map
4. chart the effects of these winds on the currents
5. produce a powerpoint presentation displaying his data and findings 

Duration of Lesson: Three 50 minute lessons

Materials: 

1. small rectangular pan (dissecting pan, biscuit pan), 1 pan for every group of 4 students
2. photocopy of a map of the North Atlantic from the Arctic Circle to the tropic of Capricorn (the map should be sized to fit the pan
3. approximately 1-2 lb. of clay per team
4. clay sculpting tools (if desired)
5. Rheoscopic fluid, (obtainable from any science supply catalog) 
   1 bottle for every 1-2 lab teams
6. blue food coloring to tint the rheoscopic fluid
7. drinking straws for each student
8. small piece cork or Styrofoam for each lab team

Technology Tools/Courseware:

1. computer with Microsoft Word and Microsoft Powerpoint
2. scanner

Teacher Notes:

• students should have already studied the surface winds and the general direction of each
• teams should have enough copies of the map to plot several (many) trans-Atlantic voyages of the cork
• students should be familiar with powerpoint enough to do a simple animation of a red dot across the page and set a picture  as the background Click here for an example presentation
• students should practice blowing on the ocean striving for consistency of angle and air speed. It is important not blow evenly and smoothly.  promise the students that after the exercise they can produce some rough weather.

Procedures:

Day one: 

1. Distribute pans, clay and maps.
2. With a marker boldly mark on the map the Arctic Circle the Equator and the 2 tropic circles
3. Insert maps into the bottom of the pan.
4. Form the continents by molding clay over the land masses to a one inch thickness. With a pencil clearly indicate in the clay the latitude lines previously marked on the map, Arctic Circle, etc.

Day two: 

1. Tint the rheoscopic fluid with blue food coloring while in the bottle.
2. Pour fluid into pan to form the ocean.
3. Assign 1 team member to plot the movement of the cork, and 1 member each to be the westerly winds, Northeast Trade winds and Southeast Trade winds.
4. Wind positions:
   
   • The student assigned to be the westerly wind should blow his straw from Cuba aiming for England.
   • The student assigned to be the Northeast Trade winds should position his straw from where the tropic of cancer meets with western Africa and aim for the mouth of the Amazon in Brazil. 
   • The student assigned to be the Southeast Trade winds should position his straw from where the Tropic of Capricorn intersects the southern tip of Africa and also blow towards the mouth of the Amazon in Brazil
5. Position the cork along the coast of either hemisphere, and make an attempt.  (see teacher note) 
6. Plot the course on one of the maps. Label each attempt.

Day Three: 

1. Scan the map. Save the file.
2. Import the picture as the background of a powerpoint slide.
3. The group should choose one of their plots to put on powerpoint.
4. Using the draw toolbar, insert a small circle representing the cork.
5. Copy and paste one circle at a time placing it in the desired route.
6. Using the custom animation feature under the slide show button on the toolbar, animate the ovals.
7. The ovals will be listed in the timing box as oval 1, oval 2 etc.
8. Select 1 oval at a time selecting that each oval be animated automatically after .3 sec and then under the effect tab select that the oval appear.
9. Save under lab-team name.

Modifications: 

Rather than scanning, a map from the internet could be downloaded for a background. This could be copied as a student map also

Enrichment Activities: 

• Research could be done on the routes of the 16th century explorers, Columbus et. al. These routes could be put into the powerpoint presentation, comparing the route with that of the student teams.
• The class could read of the voyages of Thor Heyerdahl the Norwegian anthropologist that built replicas of an ancient sailing vessels and sailed both oceans. His novel ConTiki tells of his Pacific voyage.

Evaluation/Assessment:

The students will be observed for participation and understanding during the exercise and will present their powerpoint presentation for the class.

Science: 8.1, 8.2, 8.3, 8.5, 8.6, 8.8, 8.10, 8.11, 8.12, 8.14, 8.15, 8.16, 8.21, 8.49, 8.75, 8.77, 8.78, 8.82, 8.84, 8.85, 8.86
Art: SAI.1, SAI.2, SAI.3

National Standards:

Science:

• Understands atmospheric processes and the water cycle
  
  • Knows the composition and structure of the Earth's atmosphere (e.g., temperature and pressure in different layers of the atmosphere, circulation of air masses)

Fine Arts:

• Understands and applies media, techniques, and processes related to the visual arts
  
  • Knows how to use structures (e.g., sensory qualities, organizational principles, expressive features) and functions of art
    
    • Knows how the qualities of structures and functions of art are used to improve communication of one's ideas

Science/Natural Resources
Engineering/Technical
Fine Arts/Humanities

References: 

National Geographic Society
Carolina Biological Supply Company

Authors: Bryan Barnett, Patricia Ryan and Judy Staats