Institutional Repository of Key Laboratory of Ocean Circulation and Wave Studies, Institute of Oceanology, Chinese Academy of Sciences
| 南大洋印度洋扇形区南极绕极流和南极沿岸流的相互作用研究 | |
| 史久新 | |
| Subtype | 博士 |
| 2000 | |
| Degree Grantor | 中国科学院海洋研究所 |
| Place of Conferral | 中国科学院海洋研究所 |
| Degree Discipline | 物理海洋学 |
| Keyword | 南大洋 南极绕极流 冰－海耦合 印度洋扇形区 海洋热力学 |
| Abstract | 本文利用数值方法对南大洋印度洋扇形区南极绕极流（ACC）和南极沿岸流的相互作用进行了研究，重点研究了凯尔盖朗海台区ACC的非纬向性特征及其季节变化，对其非纬向性的形成机制进行了理论探讨。基于OPYC模式，我们建立了一个冰－海耦合的南大洋等密面模式，模式中全面考虑了热力学和动力学过程，采用月均的ECMWF资料作为强迫场，海－气间的热量通量和淡水通量均根据实测的大气资料计算。模式的计算域包括了整个南大洋，利用变网格技术在所关心的重点区域进行了网格加密。模拟出的南大洋环流和海冰与已有的实测结果符合良好。本文计算的德雷克海峡处ACC的流量为145Sv，较FRAM的结果（200Sv）更加接近实测值（134Sv）。对模拟结果的分析表明，ACC与沿岸流的相互作用可呈现出不同的方式。在印度洋扇形区，ACC与沿岸流非常接近，由于岸线和地形的变化在ACC和沿岸流之间形成一系列的涡旋，这里是ACC与沿岸流直接发生相互作用的地区。这种相互作用与凯尔盖朗海台区ACC的带状分布和非纬向性特征有关。ACC流经凯尔盖朗海台时，分别从海台的北部、中部和南部经过，其南部的一个分支贴近南极大陆沿岸，它与西向的陆坡流之间的相互作用构成了印度洋扇形区ACC与沿岸流相互作用的主要部分。模拟结果显示，凯尔盖朗海台以北ACC的变化以年周期为主，海台以南的变化以半年周期为主，其时间变化规律与这里风应力的变化规律是一致的。理论分析表明，凯尔盖朗海台区ACC的非纬向性主要是由风应力和海底地形的变化造成的，它通过该海台时的南北路径的分叉和转向与该海区风应力与水深之比的旋度的分布相吻合。 |
| Other Abstract | The interaction between Antarctic Circumpolar Current (ACC) and Antarctic coastal current in the Indian section of the Southern Ocean is investigated in this paper by using numerical and theoretical methods. Especially, The non-zonation of ACC in the region of Kerguelen Plateau and its annual variation are analyzed. Based on OPYC model, a coupled sea ice-ocean isopycnal numerical model of the Southern Ocean is established. Both dynamic and thermodynamic processes are included in this model. The forcing fields, including heat flux and fresh water flux, are calculated from monthly mean data(ECMWF). The model domain covers the entire Southern Ocean and the grids are variable so that a high resolution is available in the focus area. The simulated circulation and sea ice cover agree well with the observed data. The modeled mean transport through Drake Passage is 145Sv that is very close to the observed value (134Sv) compared with the value by FRAM(200Sv). The simulated circulation displays some different patterns in the Southern Ocean due to the interaction between ACC and coastal current. In the Indian section, ACC is close to the coastal current so a number of eddies appear between ACC and the coastal current owing to the variations of coastal line and topography. This kind of interaction is a result of the non-zonation of ACC in the region of Kerguelen Plateau. ACC passes through the northern, southern and middle of the plateau separately. The interaction between the southern branch of ACC and the westward Antarctic Slope Current is the main part of the interaction between ACC and coastal current in this area. The southern branch of ACC bypassing the north part of the Kerguelen Plateau behaves like an annual variation while the southern one displays a semi-annual variation. The variations of both branches are consistent with the variations of the wind stress in both regions. A theoretical analysis shows that the non-zonation of ACC in the region of Kerguelen Plateau is due to the changes in potential vorticity of the water column caused by the curl of the ratio of wind stress to topography. The bifurcation and turning of ACC is related to the curl distribution. |
| Pages | 71 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | http://ir.qdio.ac.cn/handle/337002/275 |
| Collection | 海洋环流与波动重点实验室 |
| Recommended Citation GB/T 7714 | 史久新. 南大洋印度洋扇形区南极绕极流和南极沿岸流的相互作用研究[D]. 中国科学院海洋研究所. 中国科学院海洋研究所,2000. |
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