PURPOSE

• To demonstrate how information received from a satellite is collected and made into a useful product
• To demonstrate the relationship between El Niño and the TOPEX/POSEIDON

OBJECTIVES

• Students will a make a contour map of the ocean surface
• Students will identify the low and high points on the ocean surface
• Students will explain the relationship between El Niño and the ocean surface levels
• Students will identify El Niño vs. La Niña, by observing TOPEX/POSEIDON images

MATERIALS

1. A sturdy cardboard shoe box or boot box, with outer dimensions ranging from 14x8x4 to 14x12x4
2. Rectangular green Styrofoam (commonly used in flower arrangements and available at craft stores and florists) with dimensions matching those of the box
3. A tool to shape the Styrofoam, such as a large spoon, or the back of a tile cutting knife
4. A sharpened pencil or similar object to punch holes in the box
5. A plastic coffee stirrer at least 5 inches long
6. Tape
7. TOPEX/POSEIDON packet (MAKE COPIES OF ALL THE MAPS IN THE PACKET)
   • Packets can be received by contacting Allen Lewis at lewis@tsgc.utexas.edu
   • A Blank 8x14 Sea Level Height as Measured by TOPEX/POSEIDON maps
   • 3 -TOPEX/POSEIDON Sea Level Anomalies maps
8. A ruler or tape measure
9. Blank 3x5 index card

PROCEDURE

1. Tape the map titled " Sea Level Height as Measured by TOPEX/POSEIDON" on the top of the box so that it is centered. See Picture 1.
2. Using the pencil or other sharp object, punch holes at each intersection of coordinate lines ( over 250 holes). The holes should be just large enough for the coffee stirrer to fit through. See Picture 1 (outside view) and Picture 3 (inside view).
3. Measure and cut a 4" thick piece of Styrofoam to fit inside the box.
4. If the Styrofoam rectangle is not one solid piece, ensure that there are no gaps in the Styrofoam, and tape around the outside of the rectangle.
5. Choose a Sea Level Anomalies Map ( see picture 2), and place it over the coordinate map on the box.
6. Using the Anomalies map as a guide, shape the Styrofoam in the box to represent the level of the ocean surface. The Styrofoam near the top of the box represents surface elevations of (+) 20-24 cm, while the bottom of the box represents elevations of (-) 16-20 cm. The surface of the Styrofoam should correspond to the contour lines of the Sea Level Anomalies map.
7. Remove the anomalies map from the top of the box. The box is ready for your class to use. (See Picture 3)

PREAPARING THE HEIGHT CODE CARD (Advance preparation optional)

1. For each box, use an index card to make a "Height Code Card".
2. Barely insert the stirrer into the box through one of the holes punched in the top of the box top, place an index card next to the stirrer and mark a line where the top of the stirrer is on the card. This line indicates the (+) 24 cm height of the ocean.
3. Beginning with the 24 cm line, mark off 0.5 cm increments, up to 10 cm. Each line represents an ocean elevation of 2 cm lower than the one above it. Mark whole cm marks only (e.g., 24, 20,...,-12, -16).
4. Test the accuracy of your card by inserting the stirrer into the box at the highest point on the Styrofoam, holding the Height Code Card next to the stirrer. Be sure that this height corresponds to the height on the contour map you are using. Repeat for the lowest point on the Styrofoam.

CONSTRUCTING WAVE HEIGHT DATA

1. Students will record data on another " Sea Level Height as Measured by TOPEX/POSEIDON"
2. Beginning at one side of the map and proceeding down the longitude lines, insert the stirrer into each hole and measure the corresponding height on the Height Code Card. Record each measurement on the blank map. Interpolate the heights to the nearest tenth of a cm.
3. Continue until each coordinate point has been measured and data recorded.

CONSTRUCTING THE CONTOUR MAP

1. When making the contour lines, it is suggested to use a pencil, and to keep high values to one side of the line and lower values to the other side.
   • Remember:
     • Contour lines may have a closed in area of higher or lower than the surroundings
     • Contour lines NEVER cross each other
2. Use the measurements plotted on the map to draw contour lines that connect points of equal elevation.
   • HINT:
     • Start at one corner with the highest or lowest value and move across the map.
     • Refer to the Sea Level Anomalies map for an idea of how it should look.
3. Color code the map according to the color key
4. Each student group will construct a particular anomaly map from the packet.
5. Students should compare maps with others and identify similarities and differences.

ASSESSMENT

• Students make accurate height measurements.
• Students accurately place contour lines.
• Students use correct colors according to the color code.

CONCLUSIONS

• Students will interpret maps to predict an impending El Niño or La Niña, or a neutral time.
• Students will discuss why the ocean surface is higher in some places than others.
• Students will discuss the significance of having ocean surface elevations available.

EXTENSIONS

• Students should research and calculate the percent of the ocean that is above or below normal
• Students should view the video " TOPEX/POSEIDON and How it Relates to El Niño".

TEKS (Texas Essential Knowledge and Skills)

• Collect information by observing and measuring
• Communicate valid conclusions
• Analyze and interpret information to construct reasonable explanations from direct and indirect evidence
• Construct simple graphs, tables, maps, and charts using tools including computers to organize, examine, and evaluate information
• Represent the natural world using models and identify their limitations
• Identify events and describe changes that occur on a regular basis

GRADE 6

• Same as 5
• Identify patterns in collected information using percent, average, range, and frequency
• Identify forces that shape features of the earth including movement of water

• Same as 5 & 6
• Describe and predict the impact of different events on the Earth

• Same as 5, 6, &7
• Identify a design problem and propose a solution
• Design and test a model to solve the problem
• Evaluate the model
• Describe interactions among solar, weather, and ocean systems
• Relate the role of oceans to climatic changes

• Same as 5, 6, 7, & 8
• Analyze the impact of the space program on the collection of data about the Earth
• Analyze the impact of floods and droughts
• Compare the topography of the oceans
• Describe the transfer of heat energy at the boundaries between the atmosphere, land masses, and ocean resulting in layers of different temperatures and densities in both the ocean and atmosphere
• Describe the effect of the phenomena such as El Niño and the Jet Stream on local weather

SUPPORT MATERIAL

A video for use with the film

• "TOPEX/POSEIDON and How it Relates to El Niño" video distributed by the Texas Space Grant Consortium. For more information contact Allen Lewis at lewis@tsgc.utexas.edu

Four web sites with TOPEX and other related material

• The Texas Space Grant's "TOPEX/POSEIDON" website: http://www.tsgc.utexas.edu/topex/
• JPL's web-site for "TOPEX/POSEIDON": http://topex-www.jpl.nasa.gov/
• The SCRIBBS Institution of Oceanography's web-site on ocean height anomalies:http://meteora.ucsd.edu/~pierce/elnino/en97/en97_01.html
• A quick, 10 day look at TOPEX/POSEIDON: http://podaac.jpl.nasa.gov/topex/

Last Modified: Tue, Nov 23, 1998
CSR/TSGC Team Web