A two-layer Gulf Stream over a continental slope
A two-layer Gulf Stream over a continental slope
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大陆坡上的两层墨西哥湾流
DOI：
10.1357/002224092784797610
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发表时间：
1992
影响因子：
0.5
通讯作者：
R. Salmon
中科院分区：
文献类型：
--
作者：
R. Salmon
本文考虑西陆坡上的两层形式的行星地转方程，其中简单的瑞利摩擦代替惯性。在无摩擦极限下，这些方程可以写成特征方程，其中顶层和底层的位涡起着黎曼不变量的作用。一般的解决方案有两种类型。在第一种类型中，特性可以交叉，并且需要摩擦来解决由此产生的冲击。在第二种类型中，两个黎曼不变量中的一个是一致的，其余的特征是一条恒定的线，并且解具有简单的显式形式。一个类似墨西哥湾流的解可以由第二类的三个解组合而成。与相应的均匀流体的解决方案相比，墨西哥湾流和它的向海逆流更强，后者是集中在一个薄的摩擦层的流的东部边缘。
We consider the two-layer form of the planetary geostrophic equations, in which a simple Rayleigh friction replaces the inertia, on a western continental slope. In the frictionless limit, these equations can be written as characteristic equations in which the potential vorticities of the top and bottom layers play the role of Riemann invariants. The general solution is of two types. In the first type, the characteristics can cross, and friction is required to resolve the resulting shocks. In the second type, one of the two Riemann invariants is uniform, the remaining characteristic is a line of constantftH, and the solutions take a simple explicit form. A solution resembling the Gulf Stream can be formed by combining three solutions of the second type. Compared to the corresponding solution for homogeneous fluid, the Gulf Stream and its seaward countercurrent are stronger, and the latter is concentrated in a thin frictional layer on the eastern edge of the Stream.