半干旱区沙尘天气近地层湍流通量及起沙研究  

Research of Turbulent Flux and Dust Emission During Sand-dust Events in Surface Boundary Layer over Semiarid Area

作　　者：周悦[1] 牛生杰[1] 邱玉珺[1] 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室/大气物理学院,江苏南京210044

出　　处：《中国沙漠》2010年第5期1194-1199,共6页Journal of Desert Research

基　　金：国家自然科学基金项目(40705005;40765001);"973"项目(2006CB403706);江苏青蓝工程云雾降水与气溶胶研究创新团队项目资助

摘　　要：利用2005年春季朱日和气象站20m气象塔的观测资料,结合同期的PM10质量浓度资料,分析了半干旱地区不同沙尘天气下近地层湍流通量的变化特征以及PM10质量浓度与起沙之间的关系。结果表明,动量通量在15:00左右达到极大值;感热通量在白天为正值,中午12:00左右达到峰值,而晚上变为负值,并在凌晨达到谷值;由于3月份下垫面湿度大,导致潜热通量经常全天为正值,并在16:00左右达到峰值;PM10质量浓度与摩擦速度的二次方呈正比,临界起沙风速和临界摩擦速度分别为7m·s-1和0.7m·s-1。The characteristics of meteorological elements of atmospheric surface layer during sand-dust events are studied based on the observational data obtained from 20 m meteorological tower in Zhurihe Meteorological Station of Inner Mongolia in spring of 2005, and in combining with the mass concentration of PM10 data a comprehensive analysis is conducted. We analyze the variation features of turbulent fluxes and the relationship between the mass concentration of PM10 and dust emission during different sand-dust events over atmosphere surface layer. It was found that： （1） The momentum flux reaches the maximum at about 15：00 BST; （2） The value of sensible heat flux is positive during the daytime and reaches the maximum at 12：00 BST, while the value changes to be negative during the nighttime and get the minimum at 24：00 BST; （3） Because the soil moisture is relatively high on March, the value of latent heat flux is positive during the whole daytime and reaches the maximum at 16：00 BST; （4） The mass concentration of PM10 is approximately proportional to the second power of friction velocity, and the threshold values of wind speed and friction velocity are found to be about 7 m·s-1 and 0.7 m·s-1, respectively.

关 键 词：沙尘天气 湍流通量 动量通量 摩擦速度 临界摩擦速度 

分 类 号：P434.5[天文地球—大气科学及气象学]