Large eddy simulation of radiation fog: impact of dynamics on the fog life cycle
Large eddy simulation of radiation fog: impact of dynamics on the fog life cycle
复制标题
辐射雾大涡模拟：动力学对雾生命周期的影响
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
L. Musson
中科院分区：
文献类型：
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作者：
M. Mazoyer;C. Lac;O. Thouron;T. Bergot;V. Masson;L. Musson
抽象的。对ParisFog实验期间发生的一次辐射雾事件进行了大涡模拟研究，以分析边界层动力学对雾生命周期的影响。大涡模拟采用中尺度模式，水平分辨率为5 m，垂直分辨率为1 m，采用2矩微物理方案，考虑了树木屏障的阻力效应和水滴对植被的沉积作用。该模型与近地表动力学和热力学参数以及液态水路径的测量结果吻合较好。树木的阻挡作用导致了实际观察到的上升雾的形成，以及形成过程中的水平不均匀。它还限制了冷却和云水的生产。研究发现，沉积对雾预报的影响最大，因为它不仅侵蚀近地表的雾，而且改变了雾的生命周期，导致垂直非均匀。与2 m水平分辨率模拟相比，差异很小，这意味着实现了网格收敛。相反，通过低阶风平流算符增加数值扩散会导致液态水路径的增加，并具有与移除树木屏障非常相似的效果。这项研究使我们能够确定在非常高的分辨率下准确地表示雾的生命周期所需的主要动力学成分。
Abstract. Large eddy simulations (LESs) of a radiation fog event occurring during the ParisFog experiment are studied with a view to analyse the impact of the dynamics of the boundary layer on the fog life cycle. The LES, performed with the Meso-NH model at 5 m resolution horizontally and 1 m vertically, and with a 2-moment microphysical scheme, includes the drag effect of a tree barrier and the deposition of droplets on vegetation. The model shows good agreement with measurements of near-surface dynamic and thermodynamic parameters and liquid water path. The blocking effect of the trees induces elevated fog formation, as actually observed, and horizontal heterogeneities during the formation. It also limits cooling and cloud water production. Deposition is found to exert the most significant impact on fog prediction as it not only erodes the fog near the surface but also modifies the fog life cycle and induces vertical heterogeneities. A comparison with the 2 m horizontal resolution simulation reveals small differences, meaning that grid convergence is achieved. Conversely, increasing numerical diffusion through a wind advection operator of lower order leads to an increase in the liquid water path and has a very similar effect to removing the tree barrier. This study allows us to establish the major dynamical ingredients needed to accurately represent the fog life cycle at very high-resolution.
影响因子：
8.9
作者：
Schröder G;Schlünzen K.H;Schimmel F.
通讯作者：
Schimmel F.