Abstract Fronts are ubiquitous dynamic processes in the ocean, which play a significant role in the ocean dynamical and ecological environments. In this paper strong temperature fronts are investigated on the shelf of the Northern South China Sea using high resolution satellite data. These fronts have large horizontal gradients exceeding 1 °C km−1 with spatial scales around several kilometers. The fronts generate meanders and eddies due to baroclinic instability, since these instabilities have spatial scales around the local first baroclinic mode deformation radius. The estimated Rossby number of the fronts is O(0.4), suggesting that the fronts tend to be ageostrophic and show submesoscale features. The Finite Size Lyapunov Exponent analysis of the generation mechanism indicates that the fronts are tightly related to the combined flow straining of geostrophic and Ekman currents.

中文翻译：

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卫星在南海北部海域观测到的亚尺度锋

摘要 锋是海洋中普遍存在的动力过程，在海洋动力和生态环境中起着重要作用。本文利用高分辨率卫星数据研究了南海北部陆架上的强温度锋。这些锋面具有超过 1 °C km-1 的大水平梯度，空间尺度约为几公里。由于斜压不稳定性，锋面会产生曲折和涡流，因为这些不稳定性具有围绕局部第一斜压模变形半径的空间尺度。锋面的估计罗斯比数为 O(0.4)，表明锋面趋于地转并显示亚中尺度特征。