Reconciling Lagrangian Diffusivity and Effective Diffusivity in Contour-Based Coordinates
文献类型：期刊论文
| 作者 | Peng, Shiqiu1,3; Qian, Yu-Kun; Liang, Chang-Xia |
| 刊名 | JOURNAL OF PHYSICAL OCEANOGRAPHY
 |
| 出版日期 | 2019 |
| 卷号 | 49期号:6页码:1521 |
| ISSN号 | 0022-3670 |
| DOI | 10.1175/JPO-D-18-0251.1 |
| 英文摘要 | The present study reconciles theoretical differences between the Lagrangian diffusivity and effective diffusivity in a transformed spatial coordinate based on the contours of a quasi-conservative tracer. In the transformed coordinate, any adiabatic stirring effect, such as shear-induced dispersion, is naturally isolated from diabatic cross-contour motions. Therefore, Lagrangian particle motions in the transformed coordinate obey a transformed zeroth-order stochastic (i.e., random walk) model with the diffusivity replaced by the effective diffusivity. Such a stochastic model becomes the theoretical foundation on which both diffusivities are exactly unified. In the absence of small-scale diffusion, particles do not disperse at all in the transformed contour coordinate. Besides, the corresponding Lagrangian autocorrelation becomes a delta function and is thus free from pronounced overshoot and negative lobe at short time lags that may be induced by either Rossby waves or mesoscale eddies; that is, particles decorrelate immediately and Lagrangian diffusivity is already asymptotic nomatter how small the time lag is. The resulting instantaneous Lagrangian spreading rate is thus conceptually identical to the effective diffusivity that only measures the instantaneous irreversible mixing. In these regards, the present study provides a new look at particle dispersion in contour-based coordinates. |
| 源URL | [http://ir.scsio.ac.cn/handle/344004/17715]  |
| 专题 | 南海海洋研究所_热带海洋环境国家重点实验室(LTO) |
| 作者单位 | 1.Qingdao Natl Lab Marine Sci & Technol, Lab Reg Oceanog & Numer Modeling, Qingdao, Shandong, Peoples R China 2.South China Sea Marine Predict Ctr, State Ocean Adm, Guangzhou, Guangdong, Peoples R China 3.Chinese Acad Sci, South China Sea Inst Oceanol, State Key Lab Trop Oceanog, Guangzhou, Guangdong, Peoples R China 4.Univ Chinese Acad Sci, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Peng, Shiqiu,Qian, Yu-Kun,Liang, Chang-Xia. Reconciling Lagrangian Diffusivity and Effective Diffusivity in Contour-Based Coordinates[J]. JOURNAL OF PHYSICAL OCEANOGRAPHY,2019,49(6):1521, 1539. |
| APA | Peng, Shiqiu,Qian, Yu-Kun,&Liang, Chang-Xia.(2019).Reconciling Lagrangian Diffusivity and Effective Diffusivity in Contour-Based Coordinates.JOURNAL OF PHYSICAL OCEANOGRAPHY,49(6),1521. |
| MLA | Peng, Shiqiu,et al."Reconciling Lagrangian Diffusivity and Effective Diffusivity in Contour-Based Coordinates".JOURNAL OF PHYSICAL OCEANOGRAPHY 49.6(2019):1521. |
入库方式： OAI收割
来源：南海海洋研究所
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