摘要
湍流运动是大气最基本的运动特征,是大气能量物质交换的主要方式。利用玛曲气候与环境综合观测研究站2006年12月至2007年1月的湍流观测资料,分析了湍流方差特征、湍流动能及湍流强度等湍流统计特征,结果表明:无量纲化的风速脉动σu/u*,σv/u*,σw/u*与稳定度z/L符合1/3次方规律;大气处于中性层结时,在近中性条件下,无量纲化风速方差σu/u*,σv/u*,σw/u*分别趋于常数A=3.42,B=3.34,C=1.02;无因次化温度脉动方差σT/|T*|和湿度脉动方差σq/|q*|与稳定度z/L的变化都比较离散,基本上不能拟合出-1/3次方规律。湍流动能随风速增大而增大,白天比夜间明显,相比之下,夜间湍流动能较小,且随风速的增大比较缓慢;湍流动能随稳定的变化是非常明显的,在稳定度近中性时湍流动能取得最大值。湍流强度Iu,Iv,Iw随风速的增大而减小,当风速在0 m/s<V<2 m/s范围内时,湍流强度变化最明显,当V>5 m/s时,湍流强度变化很小。
Turbulent motion is the basic characteristics of atmospheric motion and main method of exchange of matter and energy. In this paper, the observed turbulence data from Yellow River source region climate and environment observation and research station is used to calculate and analyze the turbulence transportation characteristic. The turbulence statistical characteristic σu/u＊ , σv/u＊ , σw/u＊. versus stability z/L are in agree with the ＂1/3＂ law, under neutral stratification condition, σu/u＊ , σv/u＊ , σw/u. is near to a constant 3.42, 3.34, 1.02 ; The turbulence kinetic energy increases when wind speed increases, especially in day time; The turbulent kinetic ener- gy is smaller in the night time than in day time, and the change trend of turbulent kinetic energy slower in night time than in day time; The change of turbulent kinetic energy virus stability parameter is obvious, and the maximum is under neutral stratification condition. The turbulent intensity increases when wind speed increases; When the wind speed is bigger than 0 and less than 2 m/s, the change of turbulent intensity is very obvious, when the wind speed is bigger than 5 m/s, the change of turbulent intensity is not obvious.
出处
《地球科学进展》
CAS
CSCD
北大核心
2012年第8期901-907,共7页
Advances in Earth Science
基金
中国科学院“西部博士”资助项目“动态植被-气候耦合模式对黄河源区放牧及生态修复工程的生态气候效应研究”
国家自然科学基金重点项目“黄河源区典型下垫面水热循环及其对区域气候的影响研究”(编号:41130961),国家自然科学基金项目“黄河源玛曲牧区草地退化对地表能量输送及碳通量特征的影响研究”(编号:40975008)资助
关键词
黄河上游
湍流统计特征
湍流动能
湍流强度
The Upper Yellow River
The statistical characteristics of the turbulent
The turbulence kinetic energy
The turbulent intensity
