Abstract With regional ocean models, generating small-scale structures is important in dynamical downscaling using the nesting method. Numerous studies have shown that the generation of small-scale features is driven by large-scale flows and information supplied at the lateral boundaries by a global-scale model or observations, along with local forcing. This work, however, finds that the conventional downscaling approach reproduces small-scale motions too weakly even to sustain the energy of the larger scales, leading to degradation of the nested simulation. Therefore, this work investigates the reason for the underestimation related to the stimulating sources evoking small-scale motions. Along with that, an efficient method is proposed to improve the quality of simulation results even though a stimulating source does not exist in the domain of simulation. In this method, the addition of artificial small-scale fluctuations along the boundaries greatly enhances the reproducibility of the model, even if there is a large spatial resolution jump between the driving data and the driven model.

中文翻译：

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区域海洋模拟中单向嵌套小尺度波动的影响和恢复

摘要 对于区域海洋模型，生成小尺度结构对于使用嵌套方法进行动态降尺度非常重要。大量研究表明，小尺度特征的产生是由全球尺度模型或观测在横向边界提供的大规模流动和信息以及局部强迫驱动的。然而，这项工作发现，传统的降尺度方法再现小尺度运动的能力太弱，甚至无法维持较大尺度的能量，从而导致嵌套模拟的退化。因此，这项工作调查了与引起小尺度运动的刺激源相关的低估的原因。与此同时，提出了一种有效的方法来提高模拟结果的质量，即使模拟领域中不存在刺激源。在该方法中，沿边界添加人工小尺度波动极大地增强了模型的再现性，即使驱动数据和被驱动模型之间存在较大的空间分辨率跳跃。