The Xiamen Symposium on Marine Environmental Sciences

2027 Xiamen Symposium on Marine Environmental Sciences

January 12-15, 2027

The Dual Role of Surface Waves on Symmetric Instability and Their Impact on Momentum Transport
ID:1334 Poster Presentation

2027-01-15 16:30 (China Standard Time)

Session:Session 70 - Small-scale physical processes in the oceanic boundary layers and their application impacts

Abstract
Symmetric instability (SI) is an important mechanism that contributes to turbulent mixing in a submesoscale front. The presence of ocean surface waves may interact with frontal current shear and lead to Craik-Leibovich type 2 (CL2) instability, which may modulate the development of SI.  In this study, we conduct a linear stability analysis to investigate the impact of surface waves on SI in a viscous submesoscale front. We systematically analyze the development and growth rates of SI and CL2 instability under various combinations of background stratification (Richardson number, Ri), horizontal buoyancy gradient, and surface wave intensity and propagation direction. Our results demonstrate that the surface waves play a dual role in modulating SI. First, they alter the stability of SI by modifying the Ertel potential vorticity (PV). Second, surface waves either suppress or enhance the SI-induced slantwise circulation via the Stokes shear force. While the former effect has been well documented (e.g., Haney et al., 2015), we show that the latter arises from the coupling between Stokes and Eulerian shears, an effect that persists even under cross-front wave conditions. Furthermore, non-linear simulations incorporating surface waves are employed to validate our linear stability results and assess wave-induced impacts on momentum transport. During the early stages, prior to the dominance of non-linear advection, the suppression or enhancement of SI-induced slantwise circulation by the Stokes shear force is clearly seen. Notably, the influence of surface waves on SI-driven momentum transport penetrates throughout the entire mixed layer even though the Stokes shear force is confined near the surface.
 
Speaker
Xinghao Jiang The Hong Kong University of Science and Technology (Guangzhou)

Author
Xinghao Jiang The Hong Kong University of Science and Technology (Guangzhou)

    Important Dates

    • Jan 30

      2026

      Session / Event proposals open

    • Mar 31

      2026

      Session / Event proposals close
      (Extended to April 7)

    • Apr 30

      2026

      Session acceptance notifications

    • Apr 30

      2026

      Abstract submissions & registration open

    • Jun 30

      2026

      Abstract submissions close
      (Extended to July 21)

    • Aug 31

      2026

      Abstract acceptance notifications

    • Sep 15

      2026

      Scientific program released

    • Oct 15

      2026

      Early bird registration closes

    • Jan 12–15

      2027

      XMAS 2027