Origin and Effects of Dusts on Surface Layers of Alborz Snows

In the spring, when there is significant amount of snow accumulated at the Alborz heights, it is observed that the white color of surface of snow has been changed by a layer of particles of clay dust. Due to geographical conditions of Iran, the origin of these dusts can not be the holes and internal zones of the Iranian plateau, so the origin of these dusts should be pursued outside the Iranian plateau. On the other hand, these particles play an important role in the intense melting of the Alborz snow in the early spring. In this paper, the source and effects of the above-mentioned dusts are studied based on field observations.