Lesson C3: Elevation and Temperature

Overview
Students will compare weather data for locations at different elevations to discover the effect that elevation has on temperature.

Objectives
Students will be able to:
 investigate how elevation affects the weather in a particular region; determine the correlation between elevation and temperature; & make basic predictions to how temperature changes with elevation.

Time
One 45 minute class period.

Materials
 Weather Learning Log or Student Worksheet. Physical map of Ecuador (back-up) Computer with Internet access.

Teacher Preparation
 LIMITED ACCESS: If technology resources are limited, you can access the weather web site before your class and print the weather data or display the weather web site using a projector or television screen. GRAPHING: Students will be creating a scatter plot for this lesson. If you are new or not familiar with graphing, please review the Graphing Tips. Weather related-topics:

Procedure

Assessment
Make each student or cooperative group responsible for their answers.

Student Activity

NOTE: The following instructions also appear in Student Activities.
Activity C3: Elevation and Temperature
Part 1: Elevation and Temperature
1. Locate and mark the following locations on a map of Ecuador.
 Location Latitude Elevation (m) High Temp. (ºC) Cotopaxi 0 5897 Quito 0 2811 Latacunga -1 2785 Ibarra 0 2228 Esmeraldas +1 7 Guayaquil -2 4
1. Which location do you think will have the highest temperature? the lowest? Why?
HINT: the effect latitude will have on the temperature for each of the locations is negligible because they are all within 2º of the equator.
2. Access the following links for each of the cities and record the high temperature for today's forecast. The first location has already been completed.
NOTE: Since these are real time weather readings, the weather stations for each of the locations may submit the current temperatures to the weather web site at different times during the day, and therefore you should only compare the high temperature readings for today's forecast.

Part 2: Analyze the Data
 Create a scatter plot of Temperature vs. Elevation using the data you collection above. Label the horizontal, or x-axis in meters from from 0 to 7,000m and the vertical, or y-axis in ºC from -15ºC to 35ºC. Add a linear trend line (line of best fit) through the data in the scatter plot. If you are using a spreadsheet program, this can be done automatically. NOTE: A trend line will not cross every point but rather there should be approximately the same number of points below the line as above it. Look the trend line. Estimate the approximate change in temperature for every increase of 1,000m in elevation. If you used a spreadsheet, determine the following: Correlation coefficient Linear regression equation Based on the graph you created above and assuming all other weather factors remained constant (same latitude, etc.), predict the temperature for the following elevations: 0 m 1000 m 2000 m 3000 m 4000 m Highest Elevation: Mt. Everest, located on the border of Nepal and Tibet, is the world's tallest mountain with an elevation of 8848m.: Assuming no other factors affected the temperature, what would be your prediction for the temperature at the summit? The actual temperature on the summit of Mt. Everest varies from -15 ºC to as low as -36 ºC. What might account for the differences between your prediction and the actual temperatures? (Hint: Locate Mt. Everest on a world map) Lowest Elevation (not under seawater): The Bentley Subglacial Trench located in Antarctica has the world's lowest elevation not under seawater at -2555m (although the trench is covered by approximately 3000m of snow and ice). Assuming no other factors affected the temperature, what would be your prediction for the temperature? The actual temperature of the trench is significantly below 0 ºC. What might account for the differences between your prediction and the actual temperatures? (Hint: locate Antarctica on a world map)

Part 3: Final Conclusions
 How does elevation affect temperature? Can you rely on one day's worth of data to determine a general trend between temperature and elevation? Explain. If you would opt to collect more data, how much do you think would be sufficient? How could you obtain this data? In the troposphere, the lowest, or inner-most layer of earth's atmosphere, both air pressure and the density of air (the number of gas molecules per cubic measurement) decrease as elevation increases. How and why do you think this affects the change in air temperature as elevation increases?

Homework
How do your conclusions compare with your hypothesis that you wrote in your How and Why statements from Activity C1: Factors that influence Temperature?