CLEAR-SKY MONOCHROMATIC EXTINCTION COEFFICIENT AND THE TRANSPARENCY IN BAHRAIN

With the aim of developing a photometric observatory in Bahrain, we fi rst started the analysis of Bahrain's sky. The extinction coefficient in magnitude scale (k) and the transparency of clear atmosphere (T) fo r Bahrain's sky have been deduced seasonally from the solar-spectrum i ntensity measurements in the wavelength range from 375 to 800 nm. A co mparison of the calculated values for the (island) climate of Bahrain with those of the (desert) climate of Egypt is also presented. We conc lude that the winter season is the best time for photometric observati ons in Bahrain. Empirical equations have been established, to show the relation between the transparency and the extinction coefficient with the wavelength for each season.