Extended deep equatorial layering as a possible imprint of inertial instability
Extended deep equatorial layering as a possible imprint of inertial instability
复制标题
扩展的赤道深层分层可能是惯性不稳定的印记
DOI：
10.1029/2004gl020845
复制
发表时间：
2004
影响因子：
5.2
通讯作者：
L. Bunge
中科院分区：
文献类型：
--
作者：
M. D'orgeville;B. Hua;R. Schopp;L. Bunge
世界海洋的深赤道轨迹受强烈的纬向流场的影响，这一点仍有待于更好地了解。惯性不稳定性被用来解释它的一些特征。在这里，我们提出了可能的原地印记，这样一个机制在赤道大西洋的温跃层以下。我们分析了观测到的50-100 m垂直尺度的均匀密度层的模式，其特征在于高达2°纬度的大纬向相干性，在赤道附近的浓度和最重要的是在混合良好的角动量区域内的垂直定位（向西喷流）。这些独特的属性表明惯性不稳定性是这种扩展分层的合理机制。受时间振荡剪切力作用的数值模拟再现了所观察到的密度分层特征。背景流中深急流的处方控制着向西急流内部分层的垂直定位。
The deep equatorial track of the world ocean is subject to intense zonal flow fields that still remain to be better understood. Inertial instability has been invoked to explain some of its features. Here we present possible in situ imprints of such a mechanism in the equatorial Atlantic Ocean below the thermocline. We analyse the observed pattern of homogeneous density layers of 50–100 m vertical scale, which are characterized by a large meridional coherency up to 2° of latitude, a concentration in the vicinity of the equator and foremost a vertical localization within regions of well‐mixed angular momentum (westward jets). These distinctive properties suggest inertial instability to be a plausible mechanism for this extended layering. Numerical simulations forced by a time‐oscillating shear reproduce the observed density layering characteristics. The prescription of deep jets in the background flow controls the vertical localization of the layering inside westward jets.