Turbidity of the atmosphere over India

In a number of papers Indian scientists have treated the problem of the dust content of the air above India. The most comprehensive of these papers is the one by Anna Mani, Oommen Chacko and S. Hariharan (1969). The authors have used the measurements within isolated parts of the solar spectrum, obtained by means of the Schott Filters OG1, Rg2 and Rg8. As such filter measurements are carried out at a rather large number of climatological stations, the authors have been able to present a synoptic idea of the turbidity in its dependence on time and geographical position. The changes with time and locality of the two turbidity parameters B and a, of which the former gives an idea of the dust content in the vertical column of air, the latter of the wavelength dependence of the light scattering, are analysed.