Carlon H R
Appl Opt. 1981 Apr 15;20(8):1316-22. doi: 10.1364/AO.20.001316.
The temperature dependence of (C(o)(s))lambda, the self-broadening coefficient for the water vapor continuum absorption at wavelength lambda, can be modeled by the equilibrium ion product of water which is tabulated widely in physics texts and handbooks. A theoretical basis for this modeling is developed from water cluster theory, and it is shown that experimental values of (C(o)(s))lambda. could be seriously in error, especially at high temperatures, if the saturation ratio (fractional RH) of water vapor is not taken into account by the experimenter for reasons other than normalization of the coefficient for partial pressure of the sample. An explanation is suggested for the departure of (C(o)(s))lambda from the usual negative dependence on increasing water vapor temperature in some experiments. Figures are given showing equilibrium sizes and populations of neutral water clusters and ions in water vapor as functions of humidity and temperature, based in part on data of Bignell and other workers.
(C(o)(s))λ是水蒸气连续吸收在波长λ处的自展宽系数,其温度依赖性可以用水的平衡离子积来建模,该平衡离子积在物理教材和手册中有广泛的列表。这种建模的理论基础是从水团簇理论发展而来的,结果表明,如果实验者出于样品分压系数归一化以外的原因未考虑水蒸气的饱和比(相对湿度分数),(C(o)(s))λ的实验值可能会出现严重误差,尤其是在高温下。针对某些实验中(C(o)(s))λ偏离通常随水蒸气温度升高而呈负相关的情况给出了一种解释。给出了一些图表,展示了水蒸气中中性水团簇和离子的平衡大小及数量随湿度和温度的变化情况,部分基于比格内尔及其他研究者的数据。