Abstract: Measurements of solar radiation from ?0.45 to 1.6 ?m during May 1969 at St. Croix (Virgin Islands) in the western tropical Atlantic showed a minimum of aerosol optical thickness near 0.6 ?m, which is probably typical of a ...

Abstract: Absolute intensities have been measured over the whole twilight at an angle of elevation of 20° in an attempt to derive quantitative data on dust concentrations in the mesosphere. With the aid of model computations based ...