Open cellular convection (OCC) over, for example, the North Sea is often observed in connection with cold-air outbreaks. It is accompanied by large temporal and spatial variability in wind speed, which affects offshore wind energy in the area. This study uses the global Model for Prediction Across Scales (MPAS), with regional mesh refinement down to convection-permitting scales of 2 km, to simulate an OCC episode in the North Sea, with a focus on wind-speed variability. Modelled data are combined with wind speeds retrieved from satellite data and in situ measurements to investigate the spatial and temporal variability of offshore wind speeds under OCC conditions from a synoptic to mesoscale perspective, and to examine the model’s ability to represent the OCC structures and wind-speed variability. The model can simulate realistic OCC structures and mesoscale wind-speed variability within the limits set by the effective model resolution. Under OCC conditions, significant differences from climatological conditions are found in the spatial wind-speed power spectrum and in 10-min wind-speed step changes. The very high horizontal mesh-cell spacing in the refinement region of 2 km, and the focus on OCC wind-speed variability, makes this the first investigation of this kind using the MPAS modelling framework with mesh refinement.

中文翻译：

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使用跨尺度预测模型研究开放式蜂窝对流期间的空间和时间风速变化，并与测量值进行比较

例如，北海的开放式蜂窝对流 (OCC) 经常与冷空气爆发有关。它伴随着风速的巨大时空变化，影响了该地区的海上风能。本研究使用全球跨尺度预测模型 (MPAS)，将区域网格细化到 2 公里的允许对流尺度，以模拟北海的 OCC 事件，重点是风速变化。建模数据与从卫星数据和原位测量中检索到的风速相结合，从天气到中尺度的角度研究 OCC 条件下海上风速的空间和时间变化，并检查模型表示 OCC 结构和风力的能力。速度变化。该模型可以在有效模型分辨率设定的范围内模拟真实的 OCC 结构和中尺度风速变化。在OCC条件下，空间风速功率谱和10分钟风速阶跃变化与气候条件存在显着差异。2 公里细化区域中非常高的水平网格单元间距，以及对 OCC 风速变异性的关注，使得这是使用具有网格细化功能的 MPAS 建模框架进行的此类研究的第一次。