地气之间物质和能量随湍流运动进行输送， 涡度相关技术是研究地气交换过程和评估大气资源的重要手段， 它对湍流特征和精确的通量观测研究具有重要的作用。本研究利用拉萨蔡公堂通量站的闭路涡度相关系统， 观测了2020年8 -11月青藏高原东部拉萨河下游地区典型高寒草甸下垫面的通量特征， 并分析了该区域生长季和非生长季不同大气稳定条件下湍流谱特征和相似性规律。结果表明： （1）生长季时期（8 -9月）， 净生态系统CO₂交换（NEE）日均值为-2.3 gC·m^-2·d^-1， 蒸散（ET）日均值为1.8 mm·d^-1， 非生长季时期（10 -11月）， NEE日均值为1.1 gC·m^-2·d^-1， ET日均值为0.3 mm·d^-1； （2）三维（u， v和w）方向的湍流风速和温度的归一化谱具有明显的惯性副区， 谱密度曲线斜率符合-2/3规律， 垂直方向（w）湍流风速分别和温度、 CO₂和H₂O等气体浓度的归一化协谱曲线斜率较高于-4/3； （3）生长季和非生长季时期大气稳定度的日变化相似， 主要随动量通量的增加而降低， 但各方向风速的归一化标准差（ \sigma / u_{*}）拟合结果不同， 生长季时期， {\sigma }_u / u_{*}、 {\sigma }_v / u_{*}和 {\sigma }_w / u_{*}分别为2.84、 2.73和1.07， 非生长季时期三者增加， 分别为3.23、 3.19和1.22， 其非生长季时期水平方向风速归一化标准差增加较明显。利用闭路涡度相关系统可以较好地观测本研究区通量特征， 并且分别考虑生长季和非生长季时期湍流风速的相似性规律参数化方案有助于更精确地观测大气资源。

Matter and energy between the land and atmosphere are transported with turbulent movement.Eddy covariance technology is an important way to evaluate atmospheric resources.It plays an important role in turbulence characteristics and accurate flux observation research.In this study， we analyzed the characteristics and similarity of turbulence spectra under different atmosphere conditions in the growing and non-growing seasons using closed-path eddy covariance system of Caigongtang flux station for the underlying surface of the typical grassland in the lower reaches of the Lhasa River in the eastern Qinghai-Xizang Plateau from August to November， 2020.The results showed： （1） During the growing season from August to September， the average daily net ecosystem CO₂ exchange （NEE） was -2.3 gC·m^-2·d^-1， and the average daily ET was 1.8 mm·day^-1， During the non-growing season from October to November， the average daily NEE was 1.1 gC·m^-2·d^-1， and the average daily ET was 0.3 mm·day^-1； （2） The normalized spectra of three-dimensional （u， v and w） direction of turbulent wind speed and temperature had obvious sub-regions of inertia， the slope of the spectra density curve conformed to the -2/3 law， and the normalized co-spectra of the vertical direction （w） turbulent wind speed and temperature， CO₂ and H₂O gas concentrations is higher than -4/3 law； （3） The daily variation of atmosphere stability during the growing and non-growing seasons was similar， mainly decreasing with the increase of momentum flux， but the normalized standard deviation （ \sigma / u_{*}） fitting results of wind speed in each direction were different.During the growing season， {\sigma }_u / u_{*}， {\sigma }_v / u_{*}， and {\sigma }_w / u_{*}were 2.84， 2.73， and 1.07， respectively.During the non-growing season， the three increased to 3.23， 3.19， and 1.22， respectively.The increase in normalized standard deviation of horizontal wind speed was obvious during the non-growing season， so the parameterization scheme of the similarity law of turbulent wind speed during the growing and non-growing seasons should be considered separately.The closed-path eddy covariance system can better realize the flux observation in this study area， and this conclusion can provide the basis for the land surface parameterization scheme that considers the similarity of the turbulent wind speed during the growing and non-growing seasons， which helps to observe the atmospheric resources more accurately.