Some elements of an optical model of the atmosphere

Photoelectric-photometric and spectrographic data obtained during twilight observations of sky brightness are analyzed to determine the height variation of the scattering factor and air turbidity in the mesosphere. It is found that the mesosphere is very dusty through its entire extent, that some regions contain a much higher dust density than others, and that the mesospheric region at heights of 40 to 50 km is characterized by an aerosol accumulation. Measurements of the degree of polarization in the mesosphere are examined which indicate that a dust layer of global horizontal extent is present at heights of 40 to 60 km. It is suggested that water vapor may condense on particles of meteoric origin at heights of 80 to 100 km.