Abstract This study investigates the design of unstructured mesh resolution and its impact on the modeling of barotropic tides along the United States East Coast and Gulf Coast (ECGC). A discrete representation of a computational ocean domain (mesh design) is necessary due to finite computational resources and an incomplete knowledge of the physical system (e.g., shoreline and seabed topography). The selection of mesh resolution impacts both the numerical truncation error and the approximation of the system’s physical domain. To increase confidence in the design of high-resolution coastal ocean meshes and to quantify the efficacy of current mesh design practices, an automated mesh generation approach is applied to objectively control resolution placement based on a priori information such as shoreline geometry and seabed topographic features. The simulated harmonic tidal elevations for each mesh design are compared to that of a reference solution, computed on a 10.8 million vertex mesh of the ECGC region with a minimum shoreline resolution of 50 m. Our key findings indicate that existing mesh designs that use uniform resolution along the shoreline and slowly varying resolution sizes on the continental shelf inefficiently discretize the computational domain. Instead, a targeted approach that places fine resolution in narrow geometric features, along steep topographic gradients, and along pronounced submerged estuarine channels, while aggressively relaxing resolution elsewhere, leads to a mesh with an order of magnitude fewer vertices than the reference solution with comparable accuracy (within 3% harmonic elevation amplitudes in 99% of the domain).

中文翻译：

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沿海海洋环流模型非结构化网格分辨率的自动先验设计

摘要 本研究调查了非结构化网格分辨率的设计及其对美国东海岸和墨西哥湾沿岸 (ECGC) 正压潮汐建模的影响。由于有限的计算资源和不完整的物理系统知识（例如，海岸线和海底地形），计算海洋域（网格设计）的离散表示是必要的。网格分辨率的选择会影响数值截断误差和系统物理域的近似值。为了增加对高分辨率沿海海洋网格设计的信心并量化当前网格设计实践的有效性，应用自动网格生成方法根据先验信息（例如海岸线几何形状和海底地形特征）客观地控制分辨率放置。每个网格设计的模拟谐波潮汐高程与参考解决方案的进行比较，参考解决方案是在 ECGC 区域的 1080 万个顶点网格上计算的，最小海岸线分辨率为 50 m。我们的主要发现表明，现有的网格设计沿海岸线使用统一分辨率，在大陆架上使用缓慢变化的分辨率大小，无法有效地离散计算域。相反，一种有针对性的方法在狭窄的几何特征、陡峭的地形梯度和明显的淹没河口通道中放置精细分辨率，同时在其他地方积极放松分辨率，导致网格的顶点数量比参考解决方案少一个数量级，但精度相当（在 99% 的域中 3% 的谐波高程幅度内）。