青藏高原东部土壤冻融过程中近地层湍流统计特征分析  

Analysis on Atmospheric Surface Layer Turbulence Characteristic during Soil Freezing and Thawing Seasons in Eastern Qinghai-Xizang Plateau

作　　者：尚伦宇[1] 吕世华[1] 张宇[1] 罗斯琼[1] 陈世强[1] 李锁锁[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所寒旱区气候变化与陆面过程重点实验室,甘肃兰州730000

出　　处：《高原气象》2011年第1期30-37,共8页Plateau Meteorology

基　　金：国家自然科学基金项目(40975008);国家重点基础研究发展计划项目(2010CB951701-2);中国科学院知识创新工程重要方向项目(KZCX2-YW-328);中国科学院寒区旱区环境与工程研究所青年人才成长基金项目(51Y084871)共同资助

摘　　要：利用玛曲黄河源区气候与环境综合观测研究站的湍流资料,分析了青藏高原东部玛曲地区土壤冻融过程中近地层湍流统计特征的差异。结果表明,冻融过程中不同阶段近地层湍流输送特征表现出一定的差异性;各个阶段不稳定层结下无量纲化的风速分量脉动方差与稳定度符合1/3次方律,近中性条件下无量纲化的风速分量脉动方差近似为常数,水平方向上的风速分量方差随地表动力学粗糙度减小而呈现逐渐增大的趋势,垂直方向上的速度脉动方差变化不大,说明下垫面的物理特性对水平速度分量方差的影响比垂直方向明显;冻融过程中不稳定层结下无量纲化的温度、湿度和二氧化碳脉动方差与稳定度符合-1/3次方律,温度和湿度的拟合系数表现为冻结状态下的值小,而冻结前和融化后的值大。Using the turbulence observation data from Maqu Yellow River Source Region Climate and Environment Observation and Research Station,the turbulence characteristics of atmospheric surface layer during soil freezing and thawing seasons in Eastern Qinghai-Xizang Plateau were analyzed.The main results show that the turbulence characteristics of atmospheric surface layer have been found differences in different periods of soil freezing and thawing processes.The normalized standard deviations of velocity components in unstable conditions increase with instability and obey a 1/3 power law during soil freezing and thawing processes.The normalized standard deviations of velocity components near neutral stratification are tend to constants.The constants of horizontal direction decrease with surface dynamic roughness length while that of vertical direction has small changes,which indicates that the physical characteristic of land surface has significant influence on the standard deviation of horizontal direction.The normalized standard deviations of temperature,specific humidity and carbon dioxide in unstable conditions decrease with instability and obey a-1/3 power law during soil freezing and thawing processes.The fitting coefficients of temperature and specific humidity in frozen period are smaller than that in unfrozen period.

关 键 词：青藏高原东部 土壤冻融过程 湍流统计特征 

分 类 号：P425.21[天文地球—大气科学及气象学]