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A new treatment of water vapor opacity

Published online by Cambridge University Press:  04 August 2017

D.R. Alexander
Affiliation:
The Wichita State University, Wichita, USA
H.R. Johnson
Affiliation:
Indiana University, Bloomington, USA
G.C. Augason
Affiliation:
NASA-Ames Research Center, Moffett Field, USA
R. Wehrse
Affiliation:
University of Heidelberg, Heidelberg, FRG

Abstract

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Although the bands of H2O are strong in cool stars, water vapor opacity has generally not been accurately treated due both to the inadequacy of laboratory data and the difficulty of treating the millions of lines involved. We report a new treatment based upon a statistical representation of the water vapor spectrum derived from available laboratory data. The statistical spectrum of water follows an exponential distribution of line strengths and random positions of lines to reproduce the line spacings and mean opacities observed in the laboratory. This statistical spectrum is then randomly sampled in the spirit of opacity sampling. Significant improvements are made in both the opacities and in the thermal structure and emergent fluxes of the model atmospheres.

Type
Stellar Coronae: Chromospheres of Cool Stars
Copyright
Copyright © Reidel 1987 

References

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