Preparation of Artificial Kosa Aerosol with Two Original Desert Sands.

Abstract

Two kinds of surface soils were sampled at Shapotou in Tengger Desert and Yanchi Shabianzi in Maowusu Desert, two well known areas as origin of sand storm, in order to prepare a typical artificial kosa aerosol. Those original desert soils were separated, by sieving, to three different particle sizes (>100, 100-50, and< 50μm) . The artificial kosa aerosol with particle size around 10μm was successfully separated from particle fraction of < 50μm by wind-driven mode tunnel system. The amount of the two artificial kosa aerosol samples thus prepared were about 2kg each from 250kg (Shapotou) and 150kg (Yanchi Shabianzi) of original desert surface soils with less than 100 μm in particle size. The minerals in artificial kosa aerosol were compared with those in natural ones collected at Lanzhou and in Japan by X-ray diffraction analysis. The artificial samples prepared were found to be very similar to Lanzhou sample rather than Japanese one. The size distributions of these artificial kosa aerosol samples were confirmed similar to a natural sample that was collected at Lanzhou in May 1993 when a strong sand storm occurred.