摘要
利用中日合作"风送沙尘的形成、输送机制及其对气候与环境影响(ADEC)的研究"项目敦煌站的观测资料,分析了2001年和2002年春季沙尘天气过程中两个沙尘参量———沙尘浓度指数(DCI)和粒子数浓度(N(d))的变化以及摩擦速度(u )和风速(u)与地面风蚀起沙的关系。结果表明:可用DCI=0.2作为扬沙、浮尘等一般沙尘天气的临界值,DCI=0.4作为沙尘暴天气的临界值;沙地和农田上起沙的临界摩擦速度分别约为0.5m·s-1和0.3m·s-1,临界风速分别约为7m·s-1和3m·s-1。农田和沙地起沙临界摩擦速度的差异,导致绿洲站沙尘天气发生的频数比沙漠站大;与地面起沙量有关的总沙尘粒子数浓度N(d>0.5μm)近似与u2 成比例。
Using the observational data of Dunhuang from 'Japan and China joint project on aeolian dust experiment on climate (ADEC) impact', the variation of two dusty parameters\_Dust Concentration Index(DCI)and Particle Number concentration(N(d)) and the relations of friction velocity(u*), wind speed(u) and dust outbreak from ground surface in spring of 2001, 2002 were analyzed. It concludes that the threshold DCI of common dusty weather is 0.2 and the threshold DCI of dust storm weather is 0.4; the thresholdfriction velocityis about 0.5 m·s-1 at desert and 0.3 m·s-1 at oasis and the thresholdwind speed is about 7 m·s-1 at desert and 3 m·s-1 at oasis. The difference of threshold friction velocity at desert and oasis results in that the occurring frequency of the dusty weather at oasis is more than that at desert. Last, it means that the total dust particle number concentrationN(d>0.5 μm) is proportional to u2* approximatively.
出处
《高原气象》
CSCD
北大核心
2003年第4期378-384,共7页
Plateau Meteorology
基金
中国科学院创新重大方向项目(KZCX2 305)
国家重点基础研究发展规划项目(G2000048703)
中国科学院中日合作项目资助
关键词
敦煌地区
沙尘天气
沙尘浓度指数
粒子数浓度
沙漠
绿洲
临界摩擦速度
Dusty weather
Dust Concentration Index
Particle number concentration
Desert
Oasis
Threshold friction velocity
