The Growth and Saturation of Submesoscale Instabilities in the Presence of a Barotropic Jet
The Growth and Saturation of Submesoscale Instabilities in the Presence of a Barotropic Jet
复制标题
正压急流存在下亚中尺度不稳定性的增长和饱和
DOI：
10.1175/jpo-d-18-0022.1
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发表时间：
2018
影响因子：
3.5
通讯作者：
B. Fox‐Kemper
中科院分区：
文献类型：
--
作者：
Megan Stamper;John R. Taylor;B. Fox‐Kemper
受最近南大洋次中尺度观测的启发，我们使用非线性数值模拟和线性稳定性分析来研究正压急流对孤立锋上次中尺度不稳定性的影响。对具有强正压急流的非静力Boussinesq方程的模拟表明，亚中尺度扰动和强垂直速度仅限于初始锋面位置附近的一个小区域。相反，在没有正压急流的情况下，次中尺度涡旋传播到计算区域的边缘，并涂抹平均锋面结构。文中还考虑了几种中等强度的射流。线性稳定性分析表明，正压急流对初始条件下线性扰动的增长率影响不大，最不稳定模的增长率最多降低约20%。另一方面，用强正压急流平均模拟结束时的流动所形成的基本状态是线性稳定的，这表明非线性过程改变了平均流动，稳定了锋面。
Motivated by recent observations of submesoscales in the Southern Ocean, we use nonlinear numerical simulations and a linear stability analysis to examine the influence of a barotropic jet on submesoscale instabilities at an isolated front. Simulations of the nonhydrostatic Boussinesq equations with a strong barotropic jet (approximately matching the observed conditions) show that submesoscale disturbances and strong vertical velocities are confined to a small region near the initial frontal location. In contrast, without a barotropic jet, submesoscale eddies propagate to the edges of the computational domain and smear the mean frontal structure. Several intermediate jet strengths are also considered. A linear stability analysis reveals that the barotropic jet has a modest influence on the growth rate of linear disturbances to the initial conditions, with at most a ~20% reduction in the growth rate of the most unstable mode. On the other hand, a basic state formed by averaging the flow at the end of the simulation with a strong barotropic jet is linearly stable, suggesting that nonlinear processes modify the mean flow and stabilize the front.
在秋季风暴期间，高能次中尺度保持强烈的混合层分层
影响因子：
3.5
作者：
Whitt, Daniel B.;Taylor, John R.
通讯作者：
Taylor, John R.
影响因子：
3.2
作者：
Bachman, S. D.;Taylor, J. R.
通讯作者：
Taylor, J. R.