Turbulent intensity and its similarity function over an Inner Mongolian grassland during spring  

作　　者：YUE Ping1,2,3, NIU ShengJie2, HU YinQiao4 & ZHANG Qiang1 1 Key Laboratory of Arid Climate Change and Reducing Disaster of Gansu Province, Key Laboratory of Arid Climate Change and Reducing Disaster of CMA, Institute of Arid Meteorology, CMA, Lanzhou 730020, China 2 Nanjing University of Information Science and Technology, Nanjing 210044, China 3 Zhangye National Meteorological Observatory, Zhangye 734000, China 4 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, China 

出　　处：《Science China Earth Sciences》2010年第5期773-780,共8页中国科学（地球科学英文版）

基　　金：supported by Ministry of Science and Technology of China (Grant No. 2005DIB3J108);National Natural Science Foundation of China (Grant Nos. 40830957, 40765001)

摘　　要：Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2008 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mongolian grassland, under the condition of spring unstable stratification of the surface layer, dependence of the similarity function of turbulent intensity on stratification stability follows a "2/3 power law". The structural function is a constant under the neutral stratification condition, and complicated under the stable condition. The calculated turbulent intensity has a close correlation with the observed one, which verifies the accuracy of the similarity functions and the suitability of the theorem of turbulent intensity in the grassland region.Macroscopic reason for the development of turbulences in fluid is the conjunction action of velocity and temperature shears. We use the 2008 spring flux observations in the surface layer over Inner Mongolian grassland, obtain the similarity functions of turbulent intensity under different stratification stability conditions, and calculate the clear day turbulent intensity in the spring, which is then analyzed and compared with the observed values of turbulent intensity. The results show that in the Inner Mongolian grassland, under the condition of spring unstable stratification of the surface layer, dependence of the similarity function of turbulent intensity on stratification stability follows a '2/3 power law'. The structural function is a constant under the neutral stratification condition, and complicated under the stable condition. The calculated turbulent intensity has a close correlation with the observed one, which verifies the accuracy of the similarity functions and the suitability of the theorem of turbulent intensity in the grassland region.

关 键 词：TURBULENT INTENSITY variance of VELOCITY SIMILARITY FUNCTION GRASSLAND 

分 类 号：P425.2[天文地球—大气科学及气象学]