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中国沙漠 ›› 2010, Vol. 30 ›› Issue (5): 1194-1199.

• 天气与气候 • 上一篇    下一篇

半干旱区沙尘天气近地层湍流通量及起沙研究

周 悦, 牛生杰, 邱玉珺   

  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
  • 收稿日期:2009-11-05 修回日期:2010-02-05 出版日期:2010-09-20 发布日期:2010-09-20

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

ZHOU Yue, NIU Sheng-jie, QIU Yu-jun   

  1. Key Laboratory of Meteorologeical Disaster, School of Atmospheric Physics, Nanjing University of Information Science & Technology, Nanjing 210044, China
  • Received:2009-11-05 Revised:2010-02-05 Online:2010-09-20 Published:2010-09-20

摘要: 利用2005年春季朱日和气象站20 m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7 m·s-1和0.7 m·s-1。

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

Abstract: 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.

Key words: sand-dust event, turbulent flux, momentum flux, friction velocity, threshold friction velocity

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