摘要
通过对珠江口海岸边近地面边界层的观测资料的研究,发现该海岸带春季大气层结呈中性或近中性状态,强稳定或者强不稳定天气过程较少;摩擦速度不仅和稳定度有关,而且随平均风速呈线性增加,地形引起的扰动对它的离散性影响较大;无因次风速方差满足相似规律并符合"1/3"次方定律,在中性或者近中性条件下,u,v,w3个方向分量的相似函数为常数:3.06、2.56、1.33;湍流强度在风速达到4～6 m/s时最弱,且变化不明显,在自由对流状态(风速小于2 m/s)时湍流发展最旺盛,风速大于6 m/s时随风速增大略有增加,水平分量比垂向分量的增幅明显;海面空气动力粗糙度在距离海面10 m高处风速为3.0 m/s时最小,其与风速成二次曲线关系;中性或近中性条件下拖曳系数平均值为1.180×10-3,与风速的关系在小于4 m/s和大于4 m/s时不同,且有不同的拟合关系式。
With the observed data from a settled location at the mouth of ZhuJiang River,the characteristics of atmospheric turbulent structure of the boundary-layer has been analyzed in this paper.The atmospheric stratification is approximately neutral in spring.The friction velocity,which has a normal distribution with atmospheric stability,is linear with wind increasing.The non-dimensional wind standard deviation accords with the power of 1/3,Monin-Obukhov similarity theory.The turbulent intensity reaches its minimum when the wind speed is between 4 m/s and 6 m/s,and when the wind speed is less than 2 m/s the turbulent intensity is likely to be maximum.The strong wind when its speed is larger than 6 m/s is likely to increase the turbulent intensity in horizontal direction.The sea surface dynamic roughness has a quadratic curve relationship with 10 m height wind speed.Under neutral condition the average drag coefficient is 1.180×10-3 and it is linear with wind speed when it is larger than 4 m/s.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第7期1-8,共8页
Periodical of Ocean University of China
基金
中国气象局行业专项(GYHY200906008)
国家自然科学基金项目(40975038)
高等学校创新引智计划项目(B07036)资助
关键词
华南海岸带
涡旋相关法
湍流结构特征
中性拖曳系数
coastal region of South China
eddy covariance
atmospheric turbulent structure
neutral drag coefficient
