Clouds interact with atmospheric radiation and substantially modify the Earth's energy budget. Cloud formation processes occur over a vast range of spatial and temporal scales, which make their thorough numerical representation challenging. Therefore, the impact of parameter choices for simulations of cloud‐radiative effects is assessed in the current study. Numerical experiments are carried out using the ICOsahedral Nonhydrostatic (ICON) model with varying grid spacings between 2.5 and 80 km and with different subgrid‐scale parameterization approaches. Simulations are performed over the North Atlantic with either one‐moment or two‐moment microphysics and with convection being parameterized or explicitly resolved by grid‐scale dynamics. Simulated cloud‐radiative effects are compared to products derived from Meteosat measurements. Furthermore, a sophisticated cloud classification algorithm is applied to understand the differences and dependencies of simulated and observed cloud‐radiative effects. The cloud classification algorithm developed for the satellite observations is also applied to the simulation output based on synthetic infrared brightness temperatures, a novel approach that is not impacted by changing insolation and guarantees a consistent and fair comparison. It is found that flux biases originate equally from clear‐sky and cloudy parts of the radiation field. Simulated cloud amounts and cloud‐radiative effects are dominated by marine, shallow clouds, and their behavior is highly resolution dependent. Bias compensation between shortwave and longwave flux biases, seen in the coarser simulations, is significantly diminished for higher resolutions. Based on the analysis results, it is argued that cloud‐microphysical and cloud‐radiative properties have to be adjusted to further improve agreement with observed cloud‐radiative effects.

中文翻译：

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增加分辨率和解决对流问题，改善了北大西洋上空云辐射效应的模拟

云与大气辐射相互作用，并大大改变了地球的能源预算。云的形成过程发生在广泛的时空尺度上，这使得它们的完整数值表示具有挑战性。因此，在本研究中评估了参数选择对云辐射效应模拟的影响。使用ICOsahedral Nonhydrostatic（ICON）模型进行了数值实验，其网格间距在2.5到80 km之间变化，并且具有不同的子网格规模参数化方法。在北大西洋上使用一刻或两刻的微物理学进行模拟，并通过网格尺度动力学对流进行参数化或明确解析。将模拟的云辐射效应与通过Meteosat测量获得的产品进行比较。此外，应用复杂的云分类算法来了解模拟和观察到的云辐射效应的差异和依赖性。针对卫星观测而开发的云分类算法也被应用于基于合成红外亮度温度的模拟输出，这是一种不受日照变化影响的新颖方法，可确保一致，公平的比较。发现通量偏差同样来自辐射场的晴空和阴天部分。模拟的云量和云辐射效应受海洋浅层云的支配，它们的行为高度依赖分辨率。在较粗略的模拟中可以看到，短波和长波通量偏置之间的偏置补偿对于更高的分辨率会大大降低。