Climate change and increased coastal urbanization are causing low-lying coastlines to become increasingly susceptible to the threat of extreme water levels and coastal flooding. Robust decision-making on adaptation in the coastal zone, based on reliable ocean-modelling tools, is therefore crucially contingent on accurate assessments of current and future storm surge hazards. This accuracy relies considerably on the quality of the wind forcing used in the ocean models. In this paper, we use a high-resolution, regional 3D ocean model (HBM) covering the North Sea and Baltic Sea to simulate extreme water levels during three extreme storm surge events with different dynamics and patterns, in order to assess their impacts along Denmark’s coastlines, which are of varying levels of complexity. We demonstrate that the model is able to reproduce the observed extreme high-water levels accurately, indicating that the system is well suited for producing simulations of present and future projections of extreme storm surges with high resulting impacts and damage potentials. Additionally, we quantify the level at which acknowledged deficiencies in the otherwise most suitable atmospheric forcing data set influence the results of the storm surge simulations. We found that reducing the temporal resolution of the forcing data – that is, replacing two out of every six time stamps with linearly interpolated values – is preferable to using the original forcing data set when recurring noise is present in these time stamps. As a result, for given storm surge events, and depending on the stage reached in the storm’s evolution, mean absolute errors can be reduced by 4.5 cm. This emphasizes the importance of considering such model fluctuations when coupling high-resolution atmosphere and ocean models.

气候变化和沿海城市化的加剧使低洼的海岸线越来越容易受到极端水位和沿海洪灾的威胁。因此，基于可靠的海洋建模工具，在沿海地区进行适应性调整的可靠决策至关重要，这取决于当前和未来风暴潮危害的准确评估。这种准确性在很大程度上取决于海洋模型中使用的风力强度。在本文中，我们使用覆盖北海和波罗的海的高分辨率区域3D海洋模型（HBM）来模拟三种具有不同动力学和模式的极端风暴潮事件期间的极端水位，以便评估它们对丹麦海域的影响。海岸线，其复杂程度各不相同。我们证明了该模型能够准确地再现观测到的极端高水位，表明该系统非常适合于模拟极端风暴潮的当前和未来预测，从而产生很高的影响和破坏潜力。此外，我们量化了本来最合适的大气强迫数据集中公认的缺陷对风暴潮模拟结果的影响程度。我们发现，降低强制数据的时间分辨率（即，用线性内插值替换每六个时间戳中的两个）比在原始噪声数据中出现重复噪声时使用原始强制数据集更可取。结果，对于给定的风暴潮事件，并根据风暴演变达到的阶段， 厘米。这强调了在耦合高分辨率大气和海洋模型时考虑此类模型波动的重要性。