冬季增城丘陵灌木林基本气象要素与湍流特征

介绍了广州增城丘陵灌木林通量站的地理环境、仪器布设，并利用该站2014年12月—2015年2月的观测资料，分析冬季华南丘陵灌木林下垫面近地层的风、温度、气压、湿度和大气稳定度等基本气象要素特征，以及湍流强度、风速归一化标准差的统计特征及通量特征。结果表明:（1）冬季增城站以北向小风为主，风速多小于4 m/s，日平均温度变化剧烈，平均相对湿度为67.94%；（2）大气稳定度集中于“±” 0.5之间，以近中性为主；冬季平均湍流强度I_u、I_v和I_w分别为0.37、0.31和0.19；在风速小于1 m/s时湍流发展旺盛，随风速增大，湍流强度减小并趋于稳定；（3）风速分量归一化标准差δ_u/u_*、δ_v/u_*、δ_w/u_*与稳定度Z/L之间满足莫宁-奥布霍夫相似理论，并呈1/3次方关系，且随|Z/L|的减小而减小，在中性层结（Z/L→0）均匀下垫面，其值为常数，分别为2.286、1.757和1.174；（4）冬季增城站的能量耗散以感热为主，晴天尤为显著；阴天感热与潜热大小相当；平均日间吸收CO₂极值为0.236 mg/(m2·s)。 

OBSERVATIONAL ANALYSIS ON WINTER TURBULENCE FEATURE OVER SHRUB ECOSYSTEM IN ZENGCHENG HILLY REGION

A brief introduction of a Zengcheng land-surface processes observation tower is given, including the equipment and geographical environment. Based on the turbulence data collected from December 2014 to February 2015 the basic micrometeorological characteristics such as wind direction, atmospheric stability, turbulence intensity etc. in the near-surface layer were investigated. The results show that: (1) The observation tower is under small northerly wind condition in winter with high amplitude of temperature variation; (2) The distribution of atmospheric stability is concentrated in ±0.5 and mainly near 0; Turbulence is active when the wind velocity is lower than 1 m/s, the intensity of turbulence will decrease with the increase of wind speed until it becomes a constant; (3) The normalized standard deviation of wind velocity components generally meet the 1/3 power low with Z/L and has the synchronous changes with |Z/L|, when |Z/L|→0, δ_u /u_*、δ_v /u_*、δ_w /u_* tend to be constant; (4) Sensible heat flux is the leading energy consumption of in winter, especially in sunny days; the maximum average diurnal absorption of CO₂ is 0.236 mg/m2·s).