大连海域近海面湍流结构及谱特征

利用黄海北部大连海域2009年10月—11月的近海面大气湍流观测资料,对湍流强度、方差相似关系、风速与温度分量谱及湍流通量协谱等进行了分析。结果表明:该海域在海风环境下湍流强度随着风速的增大逐渐减小,且强度均小于0.5;湍流方差相似关系基本上满足1/3定律,近中性环境下无量纲化三维风速方差主要受海滨地形的影响;各速度分量谱在惯性副区符合理论上的-2/3次幂规律,不稳定条件下由于湿度因素的影响,温度谱谱线在高频部分收缩较差,略有上翘;动量谱在惯性副区更接近-2/3幂率,感热谱在惯性区基本符合-4/3的分布,但是谱线分布与稳定度没有明显的规律性。

Subsurface turbulence structure and spectral characteristics in the Dalian sea area

Using the data observed in the Dalian sea area of the Northern Yellow Sea, the turbulence intensity, variation similarity, wind spectrum (u, v, w), temperature spectrum and cospectrum of turbulent fluxes are analyzed. The results show that the turbulence intensity decreases with the increase of wind speed and it is less than 0.5 when U>1m/s. The variation similarity satisfies the 1/3 law in the Kolmogorov's similarity theory. The variation similarity of 3D wind speed in the neutral condition is mainly influenced by coast topography. The wind speed spectrums satisfy the -2/3 law in the inertial subrange. The temperature spectrum shrinks poorly and becomes warped in high frequency range due to the influence of humidity in unstable conditions. The momentum spectrum satisfies the -2/3 law in the inertial subrange more, and the sensible heat spectrum appears to follow the -4/3 law, but there is no rule between the distribution of spectrums and stability.