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.)

Grade Level

This activity is most appropriate for grades 7-12.

Learning Goals

After completing this chapter, students will be able to:


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:

Information about Ozone Depletion and the Ozone Hole:

Information about UV Radiation's Health Effects on Humans

Science Standards

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

Grades 5-8 Grades 9-12

Geography Standards

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

Time Required

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.

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