A Study of Water Aerosol Absorption and Emission Effects (Including Fogs) in the 8- to 13-Micron Infrared Window

摘要

Water aerosols theoretically are capable of very strong absorption and emission in the 8 micrometers to 13 micrometers infrared atmospheric window, owing to the 10,000 increase in the absorptivity of water in this spectral region for the liquid phase as compared to that for water vapor. The author reviews his earlier papers in light of subsequenc developments reported in the literature and finds strong evidence for water aerosol activity in measurements relating to atmospheric transmission, radiance, and turbulence. Several examples are given of experimental increases in optical activity of the atmosphere with relative humidity increases, even though absolute humidities (reflecting water vapor concentrations normally stated to cause similar effects owing to wing absorption of distant lines) are quite constant. Availability and suitability of condensation nuclei are thought to be significant in determining the degree of water aerosol absorption and emission. Emission effects are most pronounced. (Author)