Parametric study of the validity of the weak-line and strong-line limits of infrared H2O band absorption

摘要

Abstract: The goal of this research was to map the regimes of validity of the weak-line and strong-line limits as a function of temperature, pressure, and path length for the 2.7 $mu@m and 6.3 $mu@m H$-2$/O absorption bands. These calculations were done using an updated version of the NASA band model. A parametric study was performed where the error in assuming the validity of the two limits was calculated as a function of the physical parameters temperature, pressure, and path length. Results were generated in the form of spectral plots of the error and as band- integrated error presented in contour plots as a function of temperature and path length. Results indicate that for both bands, the weak-line error is localized in regions of intermediate temperatures and pressures at all path lengths. The strong-line limit error shows a linear increasing trend with pressure at short path lengths, while varying as a saddle-shaped function with respect to temperature and pressure at longer path lengths. !11