珠三角丘陵灌木下垫面湍流特征  

Turbulence characteristics of hilly shrubs of Pearl River Delta

作　　者：卢栩诗 蓝长星 王宝民 LU Xushi;LAN Changxing;WANG Baomin(School of Atmospheric Sciences/Guangdong Provincial Field Observation and Research Station forClimate Environment and Air Quality Change in the Pearl River Estuary,Sun Yat-sen University,Zhuhai 519082,China;Guangdong Province Jiangmen Meteorological Administration,Jiangmen 529000,China;Institute of Meteorology and Climate Research-Atmospheric Environmental Research,Karlsruhe Institute of Technology,Garmisch-Partenkirchen 82467,Germany;Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies/Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China)

机构地区：[1]中山大学大气科学学院/广东省环珠江口气候环境与空气质量变化野外科学观测研究站,广东珠海519082 [2]广东省江门市气象局,广东江门529000 [3]卡尔斯鲁厄理工学院气象和气候研究所,德国加尔米施-帕滕基兴824674 [4].广东省气候变化与自然灾害研究重点实验室/南方海洋科学与工程广东省实验室(珠海),广东珠海519082

出　　处：《中山大学学报（自然科学版）（中英文）》2024年第5期63-72,共10页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家自然科学基金(U21A6001);广东省基础和应用基础重大项目(2020B0301030004);广东省重点实验室项目(2020B1212060025)。

摘　　要：利用2017年珠三角野外观测站湍流连续观测资料,对丘陵灌木下垫面的热量通量、CO_(2)质量浓度和通量、湍流动能等特征进行分析,结果表明:1)丘陵灌木下垫面潜热通量在全年地表能量平衡中占主导地位,对比其他类型下垫面则相反。2)CO_(2)质量浓度比其他类型下垫面低,而CO_(2)通量变化幅度远大于其他类型下垫面,说明丘陵灌木下垫面的光合作用及呼吸作用比其他植被覆盖率和密集度较低的下垫面明显较强。3)湍流动能白天大,夜间小。白天夏季湍流动能最大,冬季峰值出现时间略早于夏季。4)无量纲速度标准差随稳定度的变化满足σ_(i)/u_(*)=a(1+bζ)^(1/3)的形式,归一化风速标准差符合σ_(u)/u_(*)>σ_(v)/u_(*)>σ_(w)/u_(*)的一般规律,说明丘陵灌木下垫面的物理特性差异对垂直风速的统计量影响比水平风速的统计量小。当大气越偏离中性状态,无量纲速度标准差越大,水平方向无量纲速度标准差比垂直方向无量纲速度标准差的离散程度大。丘陵灌木下垫面的无量纲风速分量系数在三个方向上都比大部分其他类型下垫面偏高。5)协谱基本符合Kansas实验的归一化协谱。不稳定条件下,低频大涡对湍流通量有较显著的贡献。稳定条件下各协谱的谱峰所对应的无量纲频率较不稳定条件下大,暗示着受浮力抑制作用,对动量、水汽和感热有显著输送作用的涡旋尺度减小。Based on the continuous observation data of turbulence in 2017 from a field observation station in the Pearl River Delta region,the turbulence characteristics of heat flux,CO_(2)concentration and flux,and the turbulent kinetic energy of hilly shrubs were analyzed.The results show that:(1)Latent heat flux plays a dominant role in the annual surface energy balance in suburban areas,while the opposite is true for the other land surface patterns.(2)The CO_(2)concentration at the observation point is slightly lower than those at other land surface patterns,and the variation range of CO_(2)flux is much greater,indicating that the photosynthesis and respiration of hilly shrubs are significantly stronger than that at lower vegetation coverage and density land surface patterns.(3)Turbulent kinetic energy is large during the day-time but small at night,maximum in summer daytime;the peak occurs slightly earlier in winter than in summer.(4)The variation of dimensionless velocity variance with atmospheric stability is accord the form of σ_(i)/u_(*)=a(1+bζ)^(1/3);the normalized wind speed standard deviation satisfies a general law of σ_(u)/u_(*)>σ_(v)/u_(*)>σ_(w)/u_(*).It shows that the difference in physical characteristics of the hilly shrub has less effect on the vertical wind speed statistics than that of the horizontal wind speed statistics.The more the atmosphere deviates from the steady state,the greater the dimensionless velocity variance;The dimensionless velocity variance in the horizontal direction is more discrete than that in the vertical direction.The dimensionless wind velocity component coefficients in three directions of the hilly shrub are higher than those of most other land surface patterns.(5)The cospectra basically conforms to the Kansas normalized cospectra.Under unstable conditions,low-frequency vortices contribute significantly to turbulent flux.The dimensionless frequencies corresponding to the spectral peaks of each cospectra under stable conditions are larger those that under unstable condition

关 键 词：珠三角地区 丘陵灌木下垫面 湍流通量 湍流速度标准差 湍流协谱 

分 类 号：P41[天文地球—大气科学及气象学]