A linear homogeneous model for topographic control of the Antarctic Circumpolar Current
A linear homogeneous model for topographic control of the Antarctic Circumpolar Current
复制标题
南极绕极流地形控制的线性均匀模型
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
Liping Wang
中科院分区：
文献类型：
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作者：
Liping Wang
Wang 和 Huang (1994) 讨论的均质河道模型的结果被推广到一个模型，该模型的几何形状由一个纬向河道和沿同一经度的每个边界的两个部分经向屏障组成。模型运输，特别是模型环流都受到两个经向障碍的显着影响。两个部分经向屏障之间存在一个脊的临界高度，高于该高度，河道中的所有地转轮廓都被阻挡。在亚临界高脊的情况下，斯维尔德鲁普平衡不适用，并且在无粘极限下没有有限解。然而，在超临界高脊的情况下，在无粘极限下获得了通过通道传输的显式形式。在风应力均匀的情况下，输运与山脊或河道的宽度无关，与风应力和河道长度成线性正比，与山脊高度成反比。在风应力不均匀 7X = ~(1 - cos v/D) 的情况下，输运和模型参数之间的关系更加复杂。它还与山脊和河道的宽度以及两个部分经向屏障的长度有关。北方屏障的存在总是导致运输的减少。然而，南部屏障的存在增加了狭窄山脊的运输。该模型证明了通过风应力旋度迫使斯维尔德鲁普流产生地形阻力的重要性。从环流结构来看，南部屏障的存在比北部屏障的影响更为深远。北部屏障仅对环流格局产生局部影响，而南部屏障则对河道产生全局影响。此外，模型表明大部分位涡耗散发生在北部屏障周围。
The results from the homogeneous channel model discussed by Wang and Huang (1994) is extended to a model whose geometry consists of a zonal channel and two partial meridional barriers along each boundary at the same longitude. Both the model transport and especially the model circulation are significantly affected by the presence of the two meridional barriers. There is a critical height of the ridge between the two partial meridional barriers, above which all geostrophic contours in the channel are blocked. In the case with a subcritically high ridge, the Sverdrup balance does not apply and there is no finite solution in the inviscid limit. In the case with a supercritically high ridge, however, an explicit form for the through-channel transport is obtained in the inviscid limit. In the case with a uniform wind stress, the transport is independent of the width of either the ridge or the channel, and is linearly proportional to the wind stress and the length of the channel, while inversely proportional to the ridge height. In the case with a nonuniform wind stress 7X = ~(1 - cos v/D), the relation between the transport and model parameters is more complicated. It is also related to the width of both the ridge and the channel, and the lengths of the two partial meridional barriers. The presence of the northern barrier always leads to a decrease in the transport. The presence of the southern barrier, however, increases the transport for a narrow ridge. The model demonstrates the importance of the topographic form-drag generation via the Sverdrup flow forced by the wind stress curl. In terms of the circulation structure, the presence of a southern barrier has a far more profound influence than that of a northern one. The northern barrier only has a localized influence on the circulation pattern, while the southern barrier has a global influence in the channel. In addition, the model demonstrates that most of the potential vorticity dissipation occurs around the northern barrier.