We have equipped the unstructured‐mesh global sea‐ice and ocean model FESOM2 with a set of physical parameterizations derived from the single‐column sea‐ice model Icepack. The update has substantially broadened the range of physical processes that can be represented by the model. The new features are directly implemented on the unstructured FESOM2 mesh, and thereby benefit from the flexibility that comes with it in terms of spatial resolution. A subset of the parameter space of three model configurations, with increasing complexity, has been calibrated with an iterative Green's function optimization method to test the impact of the model update on the sea‐ice representation. Furthermore, to explore the sensitivity of the results to different atmospheric forcings, each model configuration was calibrated separately for the NCEP‐CFSR/CFSv2 and ERA5 forcings. The results suggest that a complex model formulation leads to a better agreement between modeled and the observed sea‐ice concentration and snow thickness, while differences are smaller for sea‐ice thickness and drift speed. However, the choice of the atmospheric forcing also impacts the agreement of the FESOM2 simulations and observations, with NCEP‐CFSR/CFSv2 being particularly beneficial for the simulated sea‐ice concentration and ERA5 for sea‐ice drift speed. In this respect, our results indicate that parameter calibration can better compensate for differences among atmospheric forcings in a simpler model (i.e., sea‐ice has no heat capacity) than in more realistic formulations with a prognostic sea‐ice thickness distribution and sea ice enthalpy.

中文翻译：

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不同大气压力下海冰模型复杂度对非结构化网状海冰/海洋模型性能的影响

我们为非结构化网状全球海冰模型FESOM2配备了一组从单柱海冰模型Icepack衍生而来的物理参数。该更新极大地拓宽了该模型可以表示的物理过程的范围。新功能直接在非结构化FESOM2网格上实现，因此可以从空间分辨率方面受益于它的灵活性。使用迭代格林函数优化方法对三种模型配置的参数空间的子集（其复杂性不断提高）进行了校准，以测试模型更新对海冰表示的影响。此外，为了探讨结果对不同大气强迫的敏感性，针对NCEP-CFSR / CFSv2和ERA5强制分别对每个模型配置进行了校准。结果表明，复杂的模型公式可以使建模的海冰浓度与观测到的海冰浓度和积雪厚度更好地吻合，而海冰厚度和漂移速度的差异则较小。但是，大气强迫的选择也会影响FESOM2模拟和观测结果的一致性，其中NCEP‐CFSR / CFSv2对于模拟海冰浓度和ERA5对于海冰漂移速度特别有利。在这方面，我们的结果表明，与具有可预测的海冰厚度分布和海冰焓的更现实的公式相比，在更简单的模型（即，海冰没有热容量）中，参数校准可以更好地补偿大气强迫之间的差异。 。