Climate model components utilizing unstructured meshes enable variable resolution, regionally enhanced simulations within global domains. Here we investigate the relationship between mesh quality and simulation statistics using the JIGSAW unstructured meshing library and the Model for Prediction Across Scales‐Ocean (MPAS‐Ocean) with a focus on Gulf Stream dynamics. In the base configuration, the refined region employs 8 km cells that extend 400 km from the coast of North America. This coastal‐refined region is embedded within a low‐resolution global domain, with cell size varying latitudinally between 30 and 60 km. The resolution transition region between the refined region and background mesh is 600 km wide. Three sensitivity tests are conducted: (a) The quality of meshes is intentionally degraded so that horizontal cells are progressively more distorted; (b) the transition region from high to low resolution is steepened; and (c) resolution of the coastal refinement region is varied from 30 to 8 km. Overall, the ocean simulations are shown to be robust to mesh resolution and quality alterations. Meshes that are substantially degraded still produce realistic currents, with Southern Ocean transports within 0.4% and Gulf Stream transports within 12% of high‐quality mesh results. The narrowest transition case of 100 km did not produce any spurious effects. Refined regions with high‐resolution produce eddy kinetic energy and sea surface height variability that are similar to the high‐resolution reference simulation. These results provide heuristics for the design criteria of variable‐resolution climate model domains.

中文翻译：

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可变分辨率北美沿海网格的MPAS海洋仿真质量

利用非结构化网格的气候模型组件可在全球范围内实现可变分辨率和区域增强的模拟。在这里，我们使用JIGSAW非结构化网格划分库和跨尺度海洋预测模型（MPAS-Ocean）研究网格质量与模拟统计量之间的关系，重点是墨西哥湾流动力学。在基本配置中，精炼区域使用8 km的单元，从北美海岸延伸400 km。这个沿海精细区域被嵌入到一个低分辨率的全球域中，像元大小在30至60 km之间横向变化。精炼区域和背景网格之间的分辨率过渡区域宽600 km。进行了三个敏感性测试：（a）故意降低网格的质量，使水平单元逐渐失真；（b）从高分辨率到低分辨率的过渡区域变陡；（c）沿海提炼区的分辨率从30公里到8公里不等。总体而言，海洋模拟显示出对网格分辨率和质量更改的鲁棒性。严重退化的网格仍然会产生现实的潮流，南部海洋的传输在优质网格结果的0.4％以内，墨西哥湾流的传输在12％以内。100 km的最窄过渡情况不会产生任何杂散效应。高分辨率的精炼区域产生的涡动能和海面高度可变性与高分辨率参考模拟相似。