Point vortex dynamics for coupled surface/interior QG and propagating heton clusters in models for ocean convection
Point vortex dynamics for coupled surface/interior QG and propagating heton clusters in models for ocean convection
复制标题
海洋对流模型中耦合表面/内部 QG 和传播 Heton 簇的点涡动力学
DOI：
10.1080/03091920108203407
复制
发表时间：
2001
影响因子：
1.3
通讯作者：
A. Majda
中科院分区：
文献类型：
--
作者：
C. Lim;A. Majda
两层准地转流中斜压点涡的动力学行为为研究各种地球物理流中的热输运提供了一个紧凑的模式，包括最近的海顿模式，海顿模式是作为对空间局部强烈表面冷却的响应的大洋对流。在这样的heton模型中，通过倾斜的heton团簇的传播，与紧凑冷却区域外部的区域的热交换达到统计平衡。这种倾斜的heton集群的聚集体的气旋涡旋在上层和反气旋涡旋在下层，集体传播几乎作为一个基本的倾斜heton对，即使个别的漩涡经历在其相对位置的变化。本文的一个主要结果是一个数学定理，证明了两层模型中存在大家族的长寿命传播的heton团簇，这种方式与早期的数值模拟在很大程度上是兼容的。两层准地转流是耦合的表面/内部准地转流的理想化。本文的第二个家庭的结果涉及系统的发展耦合表面/内部QG的哈密顿点涡动力学的传播解决方案，重点是运输热量。这些是混合物种的新涡旋系统，其中表面热粒子与准地转点涡相互作用。各种基本的两个涡的精确解，传输热量包括两个表面热粒子的相反的强度，倾斜的表面热粒子耦合到内部涡的相反的强度和两个内部倾斜的涡在不同的深度相反的强度。比较了表面/内部耦合QG模型和简单的两层模型中倾斜基元heton的传播速度。最后，在耦合表面/内部QG流的点涡解的存在性的大家庭的传播长寿命的倾斜heton集群的数学定理。
Abstract The dynamic behavior of baroclinic point vortices in two-layer quasi-geostrophic flow provides a compact model for studying the transport of heat in a variety of geophysical flows including recent heton models for open ocean convection as a response to spatially localized intense surface cooling. In such heton models, the exchange of heat with the region external to the compact cooling region reaches a statistical equilibrium through the propagation of tilted heton clusters. Such tilted heton clusters are aggregates of cyclonic vortices in the upper layer and anti-cyclonic vortices in the lower layer which collectively propagate almost as an elementary tilted heton pair even though the individual vortices undergo shifts in their relative locations. One main result in this paper is a mathematical theorem demonstrating the existence of large families of long-lived propagating heton clusters for the two-layer model in a fashion compatible to a remarkable degree with the earlier numerical simulations. Two-layer quasi-geostrophic flow is an idealization of coupled surface/interior quasi-geostrophic flow. The second family of results in this paper involves the systematic development of Hamiltonian point vortex dynamics for coupled surface/interior QG with an emphasis on propagating solutions that transport heat. These are novel vortex systems of mixed species where surface heat particles interact with quasi-geostrophic point vortices. The variety of elementary two-vortex exact solutions that transport heat include two surface heat particles of opposite strength, tilted pairs of a surface heat particle coupled to an interior vortex of opposite strength and two interior tilted vortices of opposite strength at different depths. The propagation speeds of the tilted elementary hetons in the coupled surface/interior QG model are compared and contrasted with those in the simpler two-layer heton models. Finally, mathematical theorems are presented for the existence of large families of propagating long-lived tilted heton clusters for point vortex solutions in coupled surface/interior QG flow.