The Effect of Temperature upon the Ultra-Violet Band Spectrum of Ozone and the Structure of this Spectrum

Autor: Eugene H. Melvin, Oliver R. Wulf
Rok vydání: 1931
Předmět:
Zdroj: Physical Review. 38:330-337
ISSN: 0031-899X
DOI: 10.1103/physrev.38.330
Popis: The ultraviolet absorption of ozone in the region 3400-2300A consists of a large number of bands appearing against a background of continuous absorption. The effect of temperature upon this spectrum has been studied over the range -78\ifmmode^\circ\else\textdegree\fi{} to 250\ifmmode^\circ\else\textdegree\fi{}C. A definite though small effect has been observed. Grossly it manifests itself as an increase in contrast with decreasing temperature. Photometric results show this to be a decrease in absorption between the bands, all of the bands appearing to come from normal vibrational levels of very low if not the lowest energy. Though somewhat diffuse, the bands tend to degrade to the red. The observed influence of temperature can be explained as a decrease of intensity in the continuous background, and also in the higher rotational absorption of the bands, with decreasing temperature. Discontinuities in the intensity relations and the regular spacing of certain of the bands have led to a partial vibrational analysis indicating two active vibrational degrees of freedom in the excited electronic state. The observed change in the absorption with temperature may affect somewhat the estimates which have been made of the amount of ozone existing in the upper atmosphere, and may possibly afford a method of estimating the temperature of the upper atmosphere.
Databáze: OpenAIRE