Finite-Amplitude Equilibration of Baroclinic Waves on a Jet
Finite-Amplitude Equilibration of Baroclinic Waves on a Jet
复制标题
射流上斜压波的有限振幅平衡
DOI：
10.1175/2009jas3201.1
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发表时间：
2010
影响因子：
3.1
通讯作者：
Sukyoung Lee
中科院分区：
文献类型：
--
作者：
Sukyoung Lee
摘要 采用双层准地转模型研究斜压波的平衡。在该模型中，如果背景流向喷射状轮廓松弛，则可以在模型参数空间的超临界和亚临界区域实现有限振幅斜压波解。模型方程分析和数值模型计算表明，有限振幅波平衡取决于罗斯贝波在到达临界纬度之前的破裂。这种“向喷射”的波浪破碎导致上层波浪产生的增加和垂直相位倾斜的减少。相位倾斜的这种变化对埃克曼泵浦具有重大影响，因为它削弱了某些参数设置下的下层波的阻尼，并使埃克曼泵浦能够在其他设置下充当波增长的源。这些过程共同可以解释 O(1) 振幅波平衡。从位涡 (PV) 的角度来看，波...
Abstract A two-layer quasigeostrophic model is used to study the equilibration of baroclinic waves. In this model, if the background flow is relaxed toward a jetlike profile, a finite-amplitude baroclinic wave solution can be realized in both supercritical and subcritical regions of the model’s parameter space. Analyses of the model equations and numerical model calculations indicate that the finite-amplitude wave equilibration hinges on the breaking of Rossby waves before they reach their critical latitude. This “jetward” wave breaking results in an increase in the upper-layer wave generation and a reduction in the vertical phase tilt. This change in the phase tilt has a substantial impact on the Ekman pumping, as it weakens the damping on the lower-layer wave for some parameter settings and enables the Ekman pumping to serve as a source of wave growth at other settings. Together, these processes can account for the O(1)-amplitude wave equilibration. From a potential vorticity (PV) perspective, the wave ...