Absorption is the conversion of electromagnetic energy to another form of energy through interaction with matter (Townes and Schawlow, 1955). The process can be viewed at several levels, but the end result is usually heat — radiation impinges on a body, and the body becomes warmer. An absorption spectrum indicates relative efficiency in the absorption process as a function of frequency or wavelength of the radiation. In planetary studies absorption and absorption spectra generally refer to radiation passing through material rather than being reflected by material (compare reflectance spectroscopy). For example, an absorption spectrum indicates what fraction of the radiation passing through a gas is absorbed at each wavelength.
Energy absorbed by an atom results in a change in state of the atom — one or more electrons move to higher energy levels (excitation) or are removed entirely (ionization). Energy absorbed by a molecule will cause it to rotate or vibrate more rapidly, or change...
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Bibliography
Steffes, P. G. and Eshleman V. R. (1982) Sulfuric acid vapor and other cloud-related gases in the Venus atmosphere: abundances inferred from observed radio opacity. Icarus, 51, 322–33.
Townes, C. H. and Schawlow A. L. (1955) Microwave Spectroscopy. New York: McGraw Hill.
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Simpson, R.A., Jenkins, J.M. (1997). ABSORPTION, Absorption spectrum. In: Encyclopedia of Planetary Science. Encyclopedia of Earth Science. Springer, Dordrecht. https://doi.org/10.1007/1-4020-4520-4_1
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DOI: https://doi.org/10.1007/1-4020-4520-4_1
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