Using Mass Balance to Understand Atmospheric CFCs
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This page first made public: Sep 8, 2006
This material is replicated on a number of sites as part of the SERC Pedagogic Service Project
Summary
Students use an interactive online mass balance model to help understand the observed levels of chlorofluorocarbon CFC-12 over the recent past. They then explore the influence of post Montreal Protocol emission scenarios on future CFC levels and discuss the relevance of this to stratospheric ozone recovery.
Learning Goals
Context for Use
This activity is useful in any course with a section on atmospheric trace gases and/or stratospheric ozone. It has been used successfully in an introductory meteorology course as well as an upper division course on Earth's Climate for non-majors.
Teaching Materials
The CFC Activity Page has links to:
the CFC activity in pdf format (Acrobat (PDF) 168kB Aug22 04) for easy printout;
the CFC activity in MS Word format (Microsoft Word 78kB Aug22 04) for easy editing;
- the CFC activity in pdf format for students to printout and use;
- the CFC model page so they can work through the activity.
Teaching Notes and Tips
Assessment
References and Resources
The activity "Using Mass Balance to Understand Atmospheric Levels of CFCs" described here is the third part of a four part learning module that I use in my courses when discussing Earth's Climate and Stratospheric Ozone.
Mass Balance using a water bucket model, introduces students to mass balance concepts using a water bucket model.
Trace Gases, is designed to extend the fundamental ideas and the terminology of mass balance into an atmospheric science context.
If you are short on time you can highlight key aspects of these first two activities in a lecture and then assign one or both of the activities below.
These last two activities can be done in any order and use real data to address issues that are currently of interest to many students.
- Using a mass balance model to understand carbon dioxide and its connection to global warming. This activity has been student tested, reworked, and updated over the past 12 years.
- The activity described here "Using Mass Balance to Understand Atmospheric Levels of CFCs".
