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The atmospheric chemistry is a very complex topic. Many reactions need radiation of different quality. Because of that, the chemistry of the Stratosphere is very different to the chemistry of the Troposphere. To ease the understanding scientists use modells. One of these modells is mentioned here: the Two-Chamber-Photo-Reactor-Model.
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Figure 1
a) radiation: absorption and emission: γ, UV, Vis, IR, radiowaves
b) model of the two-chamber-photoreaktor of the atmosphere
© 2004 Seesing, Tausch; Universität-Duisburg-Essen, Duisburg
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The absorption spectrum of ozone was elucidated between 1881 and 1890. As early as in 1878 Alfred Cornu, a professor of physics, found out that the spectrum of the sun (as it reaches the earth) abruptly ends at wavelengths below 300 nm as if it was cut along a sharp edge. This edge even moves towards greater wavelengths when the sun is low (Fig. 1a)
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T 1 |
Is this fact due to one of the properties of the sun or to one of the properties of the earth atmosphere?
a) How would Cornu have answered this question?
b) What is the answer according to our present knowledge almost 130 years after Cornu ? |
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Figure 2:
Layers of the atmosphere and temperature profile
© 2004 Seesing, Tausch; Universität-Duisburg-Essen, Duisburg
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T2 |
Why can we regard the earth atmosphere as a two-chamber photoreactor (Fig. 1b)? Use the temperature profile from Fig. 2 for your answer. |
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T 3 |
Why is the temperature in the upper atmosphere much higher than in the tropopause? Use the reactions from the information on ozone ("Wanted-poster-ozone") for your answer! |
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T 4 |
Explain why the wavelengths of light are quite different in the stratosphere and in the troposhere (see Fig. 2). Use the absorption curve from the "Wanted-poster-ozone" for your answer. |
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About this page:
Authors: M. Seesing, M. Tausch - Universität Duisburg-Essen, Duisburg / Germany
Rewiewer:
Last update: 2004-05-13 |
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