Analyzing the Antarctic Ozone Hole
The Antarctic ozone hole is bigger than ever. This troubling news was reported in October by scientists from NASA and the National Oceanic and Atmospheric Administration.
"Analyzing the Antarctic Ozone Hole," a chapter of the Web-based Earth Exploration Toolbook, provides guidance and the tools necessary for middle and high school students to perform their own studies of the ozone hole using data collected by a NASA satellite instrument, the Total Ozone Mapping Spectrometer.
Image to left: Students quantify the Antarctic ozone hole using NASA satellite data and image analysis software. Credit: NASA/Carleton University
Ozone gas occurs naturally in the Earth's upper atmosphere -- the stratosphere -- and is of particular interest to scientists and society because of its ability to block the sun's harmful ultraviolet rays from reaching the Earth's surface. Reduced ozone can mean increased exposure to UV, which can damage the eyes and skin of humans and animals.
After reading background information about the causes and dangers of the ozone hole, students download and examine satellite images that show ozone levels in the atmosphere above the Antarctic over an eight-year period. Each color-coded image depicts the thickness of the ozone layer as measured during the Southern Hemisphere’s spring, the time of year when ozone levels are usually at their lowest.
Using image analysis software available online, students quantify each year's ozone hole by measuring the number of pixels covered by colors representing ozone levels below a certain threshold value. Students then import their measurements into a spreadsheet program where they graph annual changes in the size of the ozone hole.
Students are encouraged to consider what might account for the year-to-year changes, to outline a plan for finding out what could have caused one year to be different than others, and to develop a strategy for conducting a similar study of the Northern Hemisphere’s Arctic region.
"Analyzing the Antarctic Ozone Hole" is geared toward students in grades 7-10 and is designed to be completed in two hours or less. It can be assigned directly to students, or used as a professional development activity to familiarize teachers with accessing and analyzing satellite data.
The Earth Exploration Toolbook is a collection of computer-based activities in which students use data analysis and visualization tools to explore the Earth. Each chapter contains a guide for teachers, step-by-step instructions for students and suggestions for further study. Activities support national education standards in science and geography.
Funded by the National Science Foundation, the Earth Exploration Toolbook is developed by a partnership between TERC's Center for Earth and Space Science Education, the Science Education Resource Center at Carleton College, the Complex Systems Research Center at the University of New Hampshire, and Columbia University's Center for International Earth Science Information Network.
Dan Stillman, Institute for Global Environmental Strategies