Specific ISO/CIE cloudless winter skies in Australia

摘要

The prevailing skies in Australia are the subtropical, clear or slightly polluted cloudless skies similar to the ISO (2004) and CIE (2003) five sky types with different turbidity conditions. Such atmospheric turbidity states also influence the simultaneous decreased penetration of direct parallel sunbeams reaching the ground through the diffusing atmospheric filter. At the same time, sunbeams are scattered by air molecules, aerosols and various atmospheric pollutants with the effect of increasing sky luminance especially around the solar corona. The clear sky luminance patterns can be determined by a combination of gradation and scattering functions as determined in those of the ISO/CIE standards and can be computerized or mathematically predicted.