# Teaching Notes

### Example Output

Example Output
Image of TOMS ozone hole data and a graph of changes in ozone hole area, 1996-2005, produced in a spreadsheet application. Click image for larger view.

In this chapter, students download and analyze ten images showing the area of the ozone hole from 1996 through 2005. They then use image analysis software to highlight, outline, and measure pixels that show ozone measurements of 225 Dobson Units or fewer.

Measurement results are imported into a spreadsheet application to produce a graph showing how the size of each October's ozone hole changed over ten years. (Click the thumbnail, right, for a larger view.)

This activity is most appropriate for grades 7-12.

### Learning Goals

After completing this chapter, students will be able to:

• interpret satellite images to understand the global distribution of ozone;
• identify the Antarctic ozone hole in satellite images;
• analyze images to quantify the area of the ozone hole over time; and
• produce a graph showing the area of the ozone hole over time.

### Rationale

This chapter gives students practice gathering data from satellite images. By examining images and the associated color scale, students learn to interpret color-coded satellite imagery. Identifying areas on images where ozone levels are below a threshold value gives students a way of visualizing what has been termed a "hole" in the ozone layer. This type of analysis can be extended to other data so users can interpret images depicting a wide variety of measurements.

### Background Information

Information about Ozone Depletion and the Ozone Hole:

### Science Standards

The following National Science Education Standards are supported by this chapter:

• 8ASI1.3 Use appropriate tools and techniques to gather, analyze, and interpret data.
The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design. The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes.
• 8ASI1.8Use mathematics in all aspects of scientific inquiry.
Mathematics is essential to asking and answering questions about the natural world. Mathematics can be used to ask questions; to gather, organize, and present data; and to structure convincing explanations.
• 8BPS1.2 Substances react chemically in characteristic ways with other substances to form new substances (compounds) with different characteristic properties.
In chemical reactions, the total mass is conserved. Substances often are placed in categories or groups if they react in similar ways; metals is an example of such a group.
• 8DESS1.8 The atmosphere is a mixture of nitrogen, oxygen, and trace gases that include water vapor. The atmosphere has different properties at different elevations.

• 12D1 Organize information in simple tables and graphs and identify relationships they reveal.

### Geography Standards

The following U.S. National Geography Standards are supported by this chapter:

• How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information from a spatial perspective
• The physical and human characteristics of places
• How physical systems affect human systems

### Time Required

• Case Study: 10 minutes
• Part 1: 30 minutes
• Part 2: 10 minutes
• Part 3: 30 minutes
• Part 4: 30 minutes

### Other Resources

Teaching Resources

These Microsoft Excel files can be used as in-class examples or as an assessment of student work.

Current Ozone Data: 2004-2011

Earth Probe, the satellite carrying the TOMS instrument, was deactivated in December 2006. Current ozone data is available for analysis from the Ozone Monitoring Instrument (OMI) on the Aura satellite. The data can be accessed and downloaded from OMI Ozone website. Scroll down the page to locate the South Pole Images. Recall that the most likely date for the Ozone hole formation is late September or early October. Download the images and use the techniques described in Parts 3 and 4 to analyze the images.

Compressed File of Ozone Data

If you are unable to locate the files for this activity, or would rather start with a complete set of images, follow the instructions below.