Observed equatorward propagation and chimney effect of near-inertial waves in the mid-latitude ocean
Observed equatorward propagation and chimney effect of near-inertial waves in the mid-latitude ocean
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中纬度海洋中近惯性波向赤道传播和烟囱效应的观测
DOI：
10.1002/essoar.10510719.1
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Yu X
中科院分区：
文献类型：
--
作者：
Yu X
利用位于大西洋东北部的系泊台阵的观测资料，研究了近惯性波（NIWs）的传播特性以及中尺度和亚中尺度过程对波浪垂直穿透的影响。长达一年的观测表明，近惯性运动主要是由当地风强迫产生的，并且它们在几次强风事件（风应力<$0.5 N m−2）之后向赤道和向下辐射。水平群速度的观测估计通常超过垂直群速度的两个数量级，与色散关系的预测一致。增强的近惯性动能和垂直切变仅在罗斯比数为O（0.1）的中尺度反气旋中发现。相比之下，一阶Rossby数的次中尺度运动对NIW的捕获和垂直穿透的影响很小，这是由于它们的水平尺度更小，时间尺度更短，并且与中尺度涡旋相比具有有限的垂直范围。
The propagation characteristics of near‐inertial waves (NIWs) and how mesoscale and submesoscale processes affect the waves' vertical penetration are investigated using observations from a mooring array located in the northeast Atlantic. The year‐long observations show that near‐inertial motions are mainly generated by local wind forcing, and that they radiate equatorward and downward following several strong wind events (wind stress ≳0.5 N m−2). Observational estimates of horizontal group speed typically exceed those of vertical group speed by two orders of magnitude, consistent with predictions from the dispersion relation. Enhanced near‐inertial kinetic energy and vertical shear are found only in mesoscale anticyclones with Rossby number of O(0.1). By contrast, submesoscale motions with order one Rossby number have little effect on the trapping and vertical penetration of NIWs, due to their smaller horizontal scales, shorter time scales, and confined vertical extent compared to mesoscale eddies.