The Formation of Nonzonal Jets over Sloped Topography
The Formation of Nonzonal Jets over Sloped Topography
复制标题
倾斜地形上非纬向喷流的形成
DOI：
10.1175/jpo-d-11-0152.1
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发表时间：
2012
影响因子：
3.5
通讯作者：
Boland E
中科院分区：
文献类型：
--
作者：
Boland E
相干喷流是海洋环流中普遍存在的特征，其特征，如方向和能量，可能会受到地形的影响。在这项研究中，作者引入了一个大尺度，地形坡度与任意取向的准地转，双周期，正压和斜压系统。在这两个系统中，流动组织成一致的倾斜非纬向喷流，垂直于正压位涡（PV）梯度。在两层系统中，上层、下层和正压位涡梯度都有不同的方向，因此急流穿过层向位涡梯度。射流穿过逐层PV梯度的事实和流体包裹PV守恒的要求一起导致了倾斜射流穿过域的漂移。像它们的纬向对应物一样，倾斜射流表现出强的输运各向异性。在两层斜压情况下，急流偏转的动力响应非常强，随着地形坡度的纬向增加，涡动能量的产生增加了几个数量级。涡流能量的这种增加也反映在射流间距的增加和横向射流运输屏障的强度的降低，显示使用有效的扩散率诊断。这里确定的动力学，而正式有效的准地转尺度的限制内，提供了重要的洞察力流动方向和流动的稳定性之间的敏感关系，在具有广泛的地形坡度的地区。
Coherent jets are ubiquitous features of the ocean’s circulation, and their characteristics, such as orientation and energetics, may be influenced by topography. In this study, the authors introduce a large-scale, topographic slope with an arbitrary orientation into quasigeostrophic, doubly periodic, barotropic and baroclinic systems. In both systems, the flow organizes itself into coherent tilted nonzonal jets that are aligned perpendicular to thebarotropicpotential vorticity (PV) gradient. In the two-layer system, the upper layer, the lower layer, and the barotropic PV gradients all have different orientations and therefore the jets cross the layer-wise PV gradients. The fact that the jets cross layer-wise PV gradients and the requirement of conservation of PV for fluid parcels together results in the drift of the tilted jets across the domain. Like their zonal counterparts, the tilted jets exhibit strong transport anisotropy. The dynamical response to jet deflection is very strong in the two-layer baroclinic case, with eddy energy production increasing by orders of magnitude as the topographic slope becomes more zonal. This increase in eddy energy is also reflected in an increase in jet spacing and a reduction in strength of the across-jet transport barriers, shown using an effective diffusivity diagnostic. The dynamics identified here, while formally valid within the constraints of quasigeostrophic scalings, provide important insight into the sensitive relationship between flow orientation and flow stability in regions with broad topographic slopes.
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影响因子：
0.5
作者：
Jianhua Lu;K. Speer
通讯作者：
Jianhua Lu;K. Speer
南大洋平均流量的涡流强迫
影响因子：
--
作者：
C. Hughes;E. Ash
通讯作者：
E. Ash
允许涡流的全球海洋模型中南大洋的涡流质量传输
影响因子：
3.2
作者：
Mei;A. Coward
通讯作者：
A. Coward
影响因子：
3.1
作者：
Beron-Vera, F. J.;Brown, M. G.;Udovydchenkov, I. A.
通讯作者：
Udovydchenkov, I. A.
影响因子：
3.5
作者：
Abernathey, Ryan;Marshall, John;Shuckburgh, Emily
通讯作者：
Shuckburgh, Emily