南海中部上层海洋湍流混合的空间分布特征及参数化模型  

Spatial variation and parameterization model of upper turbulent mixing in the central South China Sea

作　　者：周宇[1,2] 陈桂英[1] 尚晓东[1] 梁长荣[1,2] 

机构地区：[1]中国科学院南海海洋研究所热带海洋环境国家重点实验室,广东广州510301 [2]中国科学院大学,北京100049

出　　处：《海洋学报》2015年第5期24-33,共10页

基　　金：中国科学院先导性科技专项A(XDA11010202);国家自然科学基金(U1033002;41376022;41276021);科技基础性工作专项:南海海洋断面科学考察(2008FY110100)

摘　　要：通过对2010年5月南海16°N和14.5°N断面的湍流微结构剖面观测资料分析,给出了南海海盆上层湍流混合空间分布特征：在16°N断面上,上层10～400m垂向平均湍动能耗散率〈ερ〉在东侧略大于西侧;相反,在14.5°N断面上,西侧〈ερ〉均值约是东侧〈ερ〉的4倍,其中,西侧110.5°～111°E的〈ερ〉的平均值为2.6×10^-6 W/m^3,东侧118.5°E的〈ερ〉仅为5.89×10^-7 W/m^3。通过分析细结构剪切和湍流混合的相关性,发现剪切是南海中部上层强湍流混合的主要驱动力,揭示了高模态内波破碎可能是湍流混合的主要机制。另外,研究了大洋中的3种参数化模型,发现适用于大洋近海的参数化MacKinnon-Gregg（MG）模型能较好地用浮频和剪切估算南海中部深海区上层湍流耗散率。Turbulent microstructure data in sections of 16°N variation of upper turbulent mixing in central South China and 14. 5°N in May 2010 has been analyzed. The spatial Sea is investigated. The results show that, in the upper 10 to 400 m layer of 16°N section,the averaged vertical dissipation rate of turbulent kinetic energy 〈ερ〉 in the eastern sites is slightly stronger than that in the western sites. On the contrary,in 14.5°N section,it is found that 〈ερ〉in western sites is 4 times of eastern sites; 〈ερ〉 declines from a averaged value of 2.6× 10^-6 W/m^3 in the western sites （110.5°E to 111°E） to 5.89× 10^-7 W/m^3 in the eastern sites （118. 5°E）. It is found that strong fine structure current shear and 〈ερ〉 are well correlated, which suggests that the strong current shear may be the main driving force for the strong turbulent mixing. Further study has revealed that the internal wave breaking of higher mode may be the main mechanism of turbulent mixing. In addition, three kinds of parameterization models are examined. MacKinnon-Gregg （MG） model for coastal sea is preferable because that the model could estimate turbulence dissipation rate of the upper layer of the central South China Sea with buoyancy frequency and shear.

关 键 词：湍动能耗散率 南海 空间变化 参数化模型 

分 类 号：P731.26[天文地球—海洋科学]