Coastal offshore currents transport terrestrial materials from coastal areas to continental shelf areas in the upper layer; these currents are regarded as unimportant in winter when wind-driven onshore currents are dominant. In this paper, both long-term observations and high-resolution simulations in the East China Sea reveal unique wintertime offshore currents in the upper layer that are widespread in the 30–70-m isobath area and even overcome the wind-driven onshore currents at the 50–70-m isobaths. The mixed layer instabilities, frontogenesis and turbulent thermal wind, which constitute a mechanism in the generation of submesoscale offshore currents, have a growth rate that is fast enough to compete with the wind-driven dynamics when the winter monsoon is relatively weak (<10 m/s). The alternation of the weak-wind and strong-wind modes during the winter monsoons provides a general condition for the repeated occurrence of remarkable submesoscale cross-shore transport and carbon sequestration in coastal seas.

中文翻译：

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冬季亚尺度海上事件克服东海风驱动的陆上洋流

近海洋流将陆地物质从沿海地区输送到上层大陆架地区；在风驱动的陆上洋流占主导地位的冬季，这些洋流被认为是不重要的。在本文中，东海的长期观测和高分辨率模拟都揭示了上层独特的冬季海上洋流，该洋流广泛分布在 30-70 米等深线区域，甚至克服了风驱动的陆上洋流50-70 米等深线。混合层不稳定性、锋生和湍流热风构成了亚中尺度近海流产生的机制，当冬季风相对较弱（<10 m）时，其增长速度足以与风驱动动力竞争/s)。