OBSERVATIONAL STUDIES ON SANDSTORM IN HELAN MOUNTAINOUS AREA

According to the observation of the number concentration spectrum and the mass concentration of at mospheric aerosol, TSP and it sparticle sizedist ribution, micrometeorology, and the solar spectroscopic radiation, even the neutron activation treat ment of sand dust samples in Helan Mount ainousarea, the formation law of sandstrom, dust and sand blowing weather and the characteristics of climatic variation in this area and the influence of Helan Mountain are counted and analysed. In addition, the spectrum characteristics, the optical thickness and the chemical composition of sand aerosol particles are also counted and analysed.