The contribution of unknown weak water vapor lines to the absorption of solar radiation

Abstract

Thousands of unknown water vapour weak lines in the spectral region between 13200 and 22700 cm −1 are deduced from extrapolations of experimental results. These lines are then included in the HITRAN database and used in line‐by‐line calculations of atmospheric opacity with standard atmospheric profiles. The weak lines predicted by a theoretical model are also used in the line‐by‐line model to estimate their contribution to the absorption of solar radiation. The additional absorption of solar radiation is of order 1.5 to 2.5 W/m² at 45 mm precipitable water, about 8.5% to 14% of the absorption due to HITRAN lines in the spectral region. The effect is also compared with that of a continuum model.