Key parameters for the life cycle of nocturnal radiation fog: a comprehensive large-eddy simulation study
Key parameters for the life cycle of nocturnal radiation fog: a comprehensive large-eddy simulation study
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DOI：
10.1002/qj.3100
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发表时间：
2017-07-01
影响因子：
8.9
通讯作者：
Bosveld, F. C.
中科院分区：
文献类型：
--
作者：
Maronga, B.;Bosveld, F. C.
利用高分辨率的大涡模拟（LESs）研究了湍流以及大气和土壤相互作用对夜间辐射雾生命周期的影响。本文的第一部分着重于验证LES模式系统模拟辐射雾对测量数据在Cabauw（荷兰）的气象超级站。在以前的研究中，发现在雾的生命周期，深度，和液态水含量LES和观测之间的差异可以在很大程度上归因于存在的本地平流过程中的观测数据和测量数据的不确定性，用于初始化模型。此外，还发现云微物理表示中液滴数浓度的选择对雾层中液态水含量有很大的影响，但对其生命周期的影响很小。为了研究湍流混合以及土壤初始状态对土壤流动的影响，本文用理想化的初始条件分析了一组大涡模拟试验。辐射雾的发展。正如预期的那样，结果表明，湍流混合对雾形成的时间有很大的影响，这是复杂的相互作用与辐射冷却和水汽去除的露水沉积。此外，它被发现，近地面土壤温度起着关键作用的确切时间的雾形成，而近地面土壤水分是决定性的雾层的解除和消散时间。
High-resolution large-eddy simulations (LESs) are used to investigate the effect of turbulence as well as the interaction between atmosphere and soil on the life cycle of nocturnal radiation fog. The first part of the article focuses on the validation of the LES model system for simulating radiation fog against measurement data from the meteorological super-site at Cabauw (Netherlands). As in former studies, differences found in the fog life cycle, depth, and liquid water content between LES and observations can be largely ascribed to the presence of local advection processes in the observational data and uncertainty in the measurement data used to initialize the model. Moreover it is found that the choice of the droplet number concentration within the cloud microphysical representation has a high impact on the liquid water content within the fog layer, but a rather small effect on its life cycle, in the second part of the article, a set of LES runs is analysed with idealized initial conditions in order to study the effect of turbulent mixing as well as the initial state of the soil on the development of radiation fog. As expected, the results show that turbulent mixing has a strong impact on the time of fog formation, which is complicated by the interaction with both radiative cooling and water vapour removal by dew deposition. Furthermore, it is found that the near-surface soil temperature plays a key role for the exact time of fog formation, whereas near-surface soil moisture is decisive for the lifting and dissipation time of the fog layer.