Experiments with Ultraviolet Radiation and the Greenhouse Effect
Summary
Students use a solar cooker to model the greenhouse effect. They also develop their own experiments to examine the strength of ultraviolet radiation from the sun with various protective materials.
Context
Audience
This experiment was one of the labs for an undergraduate course, "Environmental Geochemistry," but could be used in any course which includes discussions of the greenhouse effect or depletion of the ozone layer.
Skills and concepts that students must have mastered
Students should understand the important parts of a successful experiment.
How the activity is situated in the course
This was an end of (spring) semester activity, both to take advantage of the sun and provide a fun way to assess their gained lab and data analysis skills. It could also be taught at the start (necessary for a fall semester course in temperate regions).
Goals
Content/concepts goals for this activity
Students should be able to:
- understand how the greenhouse effect warms the earth
- determine the effectiveness of various ways of blocking damaging uv rays
- develop their own experiments
Higher order thinking skills goals for this activity
Students will gain experience in:
- data collection, analysis, and presentation
- application of scientific concepts to daily life
Other skills goals for this activity
Students will also develop these skills:
- writing
- using Excel
- working in groups
Description of the activity/assignment
In this experiment, students use a solar cooker to model the greenhouse effect. Students collect, track, and compare data including insolation, ambient temperature, and water temperature with various instruments such as a pyranometer, thermometers, and temperature probes. They also develop their own experiments (incorporating set up, controls, data collection and presentation) to examine the strength of ultraviolet radiation from the sun with various protective materials using uv-sensitive beads. They must then analyze the data, finding correlations and conclusions, and determine the best way to present the results (tables, graphs, write-up).
Determining whether students have met the goals
Students are assessed based on several things:
More information about assessment tools and techniques.- the thoroughness of their experiment method write-up
- the presentation and analysis of their collected data
- the answers to the follow-up, critical thinking questions
Teaching materials and tips
- Activity Description/Assignment (Acrobat (PDF) 69kB Jun28 10)
- Instructors Notes (Microsoft Word 2007 (.docx) 21kB Jun28 10)
- [file 'Solution Set']
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Other Materials
Supporting references/URLs
The color-changing uv detection beads are available inexpensively from Steve Spangler Science at http://www.stevespanglerscience.com
The solar cooker I used is the HotPot Simple Solar Cooker, available at Gaiam. Other solar cookers will work, but I believe those using glass provide students with the best model for the greenhouse effect. Other cookers are available through Solar Cookers International.
The solar cooker I used is the HotPot Simple Solar Cooker, available at Gaiam. Other solar cookers will work, but I believe those using glass provide students with the best model for the greenhouse effect. Other cookers are available through Solar Cookers International.