| Qi Yongfeng,Shang Chenjing,Mao Huabin,Qiu Chunhua,Liang Changrong,Yu Linghui,Yu Jiancheng,Shang Xiaodong.Spatial structure of turbulent mixing of an anticyclonic mesoscale eddy in the northern South China Sea[J].Acta Oceanologica Sinica,2020,39(11):69-81 |
| 南海北部中尺度反气旋涡的湍流混合空间分布特征 |
| Spatial structure of turbulent mixing of an anticyclonic mesoscale eddy in the northern South China Sea |
| 投稿时间：2020-06-23 |
| DOI：10.1007/s13131-020-1676-z |
| 中文关键词: 中尺度涡 混合率 南海 GHP参数化方案 Thorpe-scale方法 |
| 英文关键词:mesoscale eddy turbulent mixing South China Sea GHP parameterization Thorpe-scale method |
| 基金项目:The National Key R&D Plan of China under contract Nos 2017YFC0305904, 2017YFC0305804 and 2016YFC1401404; the National Natural Science Foundation of China under contract Nos 41876023, 41630970, 41806037, 41706137 and 41806033; the Guangdong Science and Technology Project under contract Nos 2019A1515111044, 2018A0303130047 and 2017A030310332; the Guangzhou Science and Technology Project under contract No. 201707020037; the Natural Science Foundation of Shenzhen University under contract No. 2019078; the Dedicated Fund for Promoting High-quality Economic Development in Guangdong Province (Marine Economic Development Project) under contract No. GDOE[2019]A03; the Independent Research Project Program of State Key Laboratory of Tropical Oceanography under contract Nos LTOZZ1902 and LTO1909. |
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| 中文摘要: |
| 文章利用GHP细结构参数化方法和Thorpe-scale方法，分析水下滑翔机于2015年5月在南海北部采集的数据，估算了南海北部中尺度反气旋涡的湍流混合空间分布特征。结果显示该反气旋涡的混合具有明显的空间非对称性，混合率在其运动方向的后侧边缘明显增强达到O(10-3 m2/s)量级；而在其运动方向的前侧边缘，平均混合率要小一个量级。这一混合非对称特征与中尺度的涡动能密切相关性。中尺度涡后侧边缘处存在高流速剪切，容易引起垂向剪切不稳定，可能是引起该处混合增强的主要因素。另外，中尺度涡后侧边缘发展的次中尺度过程同样导致了该处强混合。本研究结果有助于人们进一步认识南海北部的混合过程。 |
| 英文摘要: |
| Upper turbulent mixing in the interior and surrounding areas of an anticyclonic eddy in the northern South China Sea (SCS) was estimated from underwater glider data (May 2015) in the present study, using the Gregg-Henyey-Polzin parameterization and the Thorpe-scale method. The observations revealed a clear asymmetrical spatial pattern of turbulent mixing in the anticyclonic eddy area. Enhanced diffusivity (in the order of 10–3 m2/s) was found at the posterior edge of the anticyclonic mesoscale eddy; on the anterior side, diffusivity was one order of magnitude lower on average. This asymmetrical pattern was highly correlated with the eddy kinetic energy. Higher shear variance on the posterior side, which is conducive to the triggering of shear instability, may be the main mechanism for the elevated diffusivity. In addition, the generation and growth of sub-mesoscale motions that are fed by mesoscale eddies on their posterior side may also promote the occurrence of strong mixing in the studied region. The results of this study help improve our knowledge regarding turbulent mixing in the northern SCS. |
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