Absorption by atmospheric gases of incoming and outgoing radiation
Topic: Absorption spectra, greenhouse gases, and the greenhouse effect
Course type: Introductory or upper level university, any size class
This activity teaches Climate Literacy Essential Principle 2: Climate is regulated by complex interactions among components of the Earth system
This activity teaches Concept C - Greenhouse Effect. The amount of solar energy absorbed or radiated by Earth is modulated by the atmosphere and depends on its composition. Greenhouse gases— such as water vapor, carbon dioxide, and methane— occur naturally in small amounts and absorb and release heat energy more efficiently than abundant atmospheric gases like nitrogen and oxygen. Small increases in carbon dioxide concentration have a large effect on the climate system.
GoalsStudents should be able to do the following:
- Estimate the absorption by Earth's atmosphere of both incoming and outgoing radiation
- Contrast atmospheric constituents based on their absorption spectra
- Identify greenhouse and non-greenhouse gases based on their absorption spectra
- Estimate Earth's surface temperature from satellite data
DescriptionIn small groups, students first examine a portion of the electromagnetic spectrum and the absorption spectra of seven atmospheric gases in that wavelength range.
- 0.1-3 microns,
- 3-12 microns,
- 12-40 microns.
The instructor organizes groups, circulates, provides discussion guidance, coordinates simultaneous reporting of results at the end, leads final discussion, and administers assessment. This activity (Microsoft Word 1.1MB Sep29 11) uses a jigsaw pedagogical structure.
Absorption Spectra Jigsaw Activity (Microsoft Word 1.1MB Sep29 11) - Student handout
Absorption Spectra Jigsaw Activity-for Instructor (Microsoft Word 1.1MB Sep29 11) - Instructor notes and answers
Data files provided for replotting or modification if desired by instructor:
Data: 0.1-3 microns (Excel 9.8MB Jul15 11) - For Activity 1, Group 1
Data: 3-12 microns (Excel 3.6MB Jul15 11) - For Activity 1, Group 2
Data: 12-40 microns (Excel 9.7MB Jul15 11) - For Activity 1, Group 3
Blackbody & Satellite Data: 3-40 microns (Excel 2.1MB Jul15 11) - For Activity 2
Assessment Ideas for Absorption Jigsaw (Microsoft Word 627kB Sep29 11)
Connections to other Activities
This activity is one of a suite of five activities designed to address the concepts that address how the greenhouse effect influences global temperature (Principle 2, Concept C) which can be used individually or combined as desired.
ReferencesData for this activity were obtained from SpectralCalc.com
SERC's Jigsaw module which includes example jigsaw activities
More on this topic from CLEAN
How to teach with this principle from the CLEAN site
See CLEAN reviewed activities for teaching about Greenhouse Effect