Unravelling the relative roles of physical processes in modelling the life cycle of a warm radiation fog
Unravelling the relative roles of physical processes in modelling the life cycle of a warm radiation fog
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DOI：
10.1002/qj.3300
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发表时间：
2018-07
影响因子：
8.9
通讯作者：
G. Steeneveld;M. de Bode
中科院分区：
文献类型：
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作者：
G. Steeneveld;M. de Bode
本研究通过天气研究与预报（WRF）单柱模型评估了在Cabauw 213 m塔（荷兰）设施观测到的辐射雾实例研究的生命周期的表示，旨在促进对模型行为的理解，这将有助于确定未来的研究重点。首先，对行星边界层、地表、长波辐射和微物理等参数化方案不同的16种WRF配置进行了综合评估。接下来，我们进行了敏感性研究，以检验哪些物理过程在模拟雾中最重要，即土壤热扩散率，二氧化碳浓度（代表晴空长波辐射），蒸汽扩散到液滴，以及湍流混合。随后，我们研究了这些扰动是否可以改善模型表示，另一方面，它们是否可以解释16个系综成员的模型行为。结果显示在流程图中。我们发现，土壤热扩散率和湍流混合的变化可以解释整体的行为。然而，它们的灵敏度方向大致相同，因此，边界层格式的公式误差可以通过补偿陆地表面格式的误差来隐藏。此外，我们发现土壤热扩散率和湍流混合的同时扰动与叠加单个扰动的结果不同。
This study evaluates the representation of the life cycle of a radiation fog case‐study observed at the Cabauw 213 m tower (Netherlands) facility by the Weather Research and Forecasting (WRF) single‐column model, and aims to advance the understanding of the model behaviour, which will assist in setting research priorities for the future. First an ensemble of 16 WRF configurations that vary in parametrization schemes for the planetary boundary layer, land surface, long‐wave radiation, and microphysics are evaluated. Next, we perform a sensitivity study to examine which physical process is most crucial in modelling the fog, i.e. soil heat diffusivity, the CO2 concentration (representing clear‐sky long‐wave radiation), the vapour diffusion to droplets, and the turbulent mixing. Subsequently, we study whether these perturbations can improve the model representation, and on the other hand whether they can explain the model behaviour of the 16 ensemble members. Results are displayed in process diagrams. We find that the behaviour of the ensemble can be explained by variations in the soil heat diffusivity and the turbulent mixing. However, their sensitivities orient in approximately the same direction, and as such, errors in the formulation of the boundary‐layer scheme can be hidden by compensating errors in the land‐surface scheme. In addition, we find that simultaneous perturbations in the soil heat diffusivity and turbulent mixing do not result in the same results as superposing the individual perturbations.