Περίληψη:
In this paper Ångström's turbidity coefficient β0, wave-length exponent α0 and the decadic turbidity coefficient B after Schüepp have been computed in Athens from pyrheliometric measurements of direct solar radiation for the whole spectrum and of specified spectral regions using Schott filters for the period 1963-1972. Turbidity coefficient β0 shows an annual variation with low values in winter and high values in spring. The wavelength exponent α0 shows a similar but opposite in sense variation. The decadic trubidity coefficient B is low in winter and attains the highest values in late spring and summer. In order to show the diurnal variation of the turbidity parameters this are given for each of the observation hours 0820, 1120, 1420 and 1720. The annual and diurnal variations of the turbidity parameters are discussed in reference to their relation with seasonal changes of synoptic weather situations, to the prevailing winds and the different air masses. © 1976 Springer-Verlag.
