Analysis on Aerosol Particle Number Concentration over Dunhuang Region in Spring

Using the data of aerosol particle number concentration(APNC) observed over Gobi desert and oasis crop land in Dunhuang in spring of 2002,the relationship of APNC with dusty weather,spectrum distribution characteristics and differences of APNC over the two surfaces are analyzed in this paper.The results indicate that the characteristics of APNC will vary with different weather conditions.In background weather,the total APNC is usually under 104L-1 and the main particles are very thin ones with diameter of 0.5～1.0 μm.The APNC of thin particles(diameter3.0 μm) over oasis crop land are higher than those over Gobi desert,while it is opposite for coarse particles(diameter3.0 μm).In dusty weather,the APNC in Dunhuang increases to be up to 105 L-1 and thin particles with diameter of 1.0～3.0 μm turn to be the main composition.All of the 4 classified APNC over Gobi desert are higher than that over oasis cropland,and this difference is much larger when the diameter is above 3.0 μm.