784 / 2024-09-19 13:11:38
Symmetric instability under inertially resonant winds
surface mixed layer,symmetric instability,inertial gravity waves,large eddy simulation
摘要待审
Cao Jialin / Xiamen University
Qu Lixin / Shanghai Jiao Tong University
Chen Bicheng / Xiamen University
Liu Zhiyu / Xiamen University
When wind aligns with the geostrophic flow in the upper ocean (down-front wind), it induces a negative Ertel potential vorticity (EPV) flux, initiating symmetric instability (SI) along the frontal boundary. However, surface mixed layers (SMLs) are usually subjected to fluctuating wind forcing rather than a constant, unidirectional one. Notably, near-inertial wind components can inject significant kinetic energy into the upper ocean, forming strong near-inertial oscillations. These variations in wind forcing, along with the associated near-inertial oscillations, introduce additional complexities to the energy budget of the SML. In this study, we investigate the frontal SI dynamics using large-eddy simulations with a series of wind conditions. A refined dynamical decomposition method is developed to achieve a more refined analysis of interaction between different motions. Using this method, we demonstrate that available potential energy (APE) also plays a crucial role in energizing SI. Furthermore, periodic winds enhance near-inertial motions within the system thereby rendering ageostrophic shear production (AGSP) a progressively dominant mechanism in the energy transfer process. Ultimately, our refined decomposition framework enables a detailed assessment of the feedback exerted by SI on the broader system dynamics.

 
重要日期
  • 会议日期

    01月14日

    2025

    01月17日

    2025

  • 09月27日 2024

    初稿截稿日期

  • 12月14日 2024

    注册截止日期

主办单位
State Key Laboratory of Marine Environmental Science, Xiamen University
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