The atmosphere over big Greek cities, especially Athens and Thessaloniki, has been recently burdened extensively by solid and gas aerosols. This has been the effect of the inadequate town planning and the climatological conditions in the area, in combination with the morphology relief surrounding these cities.
In Athens the Linke turbidity factor is less than 5 only during a few days around the year. In Thessaloniki the same factor has values greater than 5 at a very large percentage only during the warm semester. The picture of the Angstrom turbidity coefficient is the same. The Angstrom wavelength exponent shows that solid aerosols of small size are predominant in Thessaloniki, while large aerosols are predominant in Athens. The study of the Linke turbidity factor for specific spectral bands has led to the same conclusions.