Rui Li

This study investigates the wave-induced vertical mixing mechanism and systematically compares the application of two non-breaking wave parameterization schemes (Bv and Pw) in oceanic numerical simulations of the South China Sea, according to two key physical variables: sea surface temperature (SST) and the vertical mixing coefficient. The goal is to explore the effects of different parameterization methods on the upper-ocean temperature distribution in the South China Sea. The results indicate that although both schemes enhance vertical mixing in the upper ocean, they do so through different mechanisms. The Bv scheme directly increases the vertical mixing coefficient, demonstrating significantly stronger mixing intensity, while the Pw scheme impacts mixing indirectly by modulating turbulent kinetic energy generation, resulting in comparatively weaker mixing. SST simulation results show that the Bv scheme is more effective in reducing SST in both winter and summer, with broader spatial improvements. Further analysis of the mixing coefficient confirms that, compared to the Pw scheme, the Bv scheme not only strengthens surface mixing but also penetrates deeper into the water column.

This study employs reanalysis data published by ECMWF to investigate the impact of ocean waves on cold tongues in the southern hemisphere. Based on the global sea surface temperature (SST) patterns, the scope of the cold tongue is defined in this paper. Compared to Ekman transport, wave transport dominates and plays a critical role in the cold tongue region. This study analyzes the characteristics of cold tongues across the three major ocean, with a primary focus on the Pacific cold tongue, which serves as the most representative region. Analysis of the relationship between meridional wave transport and SST in the southeastern Pacific cold tongue indicates a lagged negative correlation between abnormal SST and meridional wave-induced water transport from high latitudes. Specifically, negative SST anomalies in the Pacific cold tongue occur 3~4 months after a positive anomaly in northward cold-water transport from high latitudes. Meridional wave transport between 30°S and 38°S has a significant cooling effect on SST in the cold tongue region, with the strongest cooling observed along the northeastern coastline. Additionally, the combined effects of northward and westward water transport result in a distinct temperature gradient in the western cold tongue. These findings highlight the connection between wave-induced transport and the cold tongue, providing a novel perspective for exploring the causes of SST anomalies.