Activity 5: Effects of greenhouse gases
With this central activity in the climate case, it is shown experimentally in two different ways that CO2 absorbs thermal radiation and the back radiation of the atmosphere is made vivid with a thermal imaging camera.
- Part: CO2 absorbs radiant energy (absorption measurement)
- Part: Infrared radiation is intercepted (transmission measurement).
- Part: Why does an absorption of infrared radiation in the atmosphere lead to a heating of the
earth surface? (Back radiation of the atmosphere)
- Description to the activity from the guide (PDF / editable word-document)
- Solution to the activity from the guide (PDF)
- DIN A3-backround text to the activity from the climate kit (all backround texts for download)
h5p-study unit for the activity:
More materials like h5p-study units, videos and animations with Module - The Greenhouse effect and the radiative Equilibrium.
Video: The effect of greenhouse gases
Technical questions and didactic comments
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- Depending on the ambient temperature, the radiator takes approx. 25 minutes to warm up. It may therefore be advisable to switch it on before the start of the hour.
- For the transmission measurement by thermal imaging camera a thermal imaging camera is necessary, where the temperature measuring range can be adjusted manually (e.g. FLIR C3X). To get a nice before and after comparison, a few settings are necessary, which are shown exemplarily with the FLIR C3X in the video of the experiment. It is recommended to vary the temperature range used, as the optimal setting also depends on the ceramic emitter used.
- Instead of a thermal imaging camera, an inexpensive IR thermometer can also be used for the transmission measurement. After CO2 has been added, the indicated temperature drops because less heat radiation reaches the IR thermometer.
Important: The IR thermometer must be fixed by means of a stand, since the temperature on the surface of the ceramic radiator is not uniform and movement of the thermometer leads to measurement errors.
- Hazard assessment
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