An improved PDF cloud scheme for climate simulations
An improved PDF cloud scheme for climate simulations
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DOI：
10.1002/qj.660
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发表时间：
2010-07
影响因子：
8.9
通讯作者：
A. Kuwano‐Yoshida;Takeshi Enomoto;W. Ohfuchi
中科院分区：
文献类型：
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作者：
A. Kuwano‐Yoshida;Takeshi Enomoto;W. Ohfuchi
在地球模拟器（AFES）的大气环流模式中实现了一种有效的网格尺度气候模拟云方案。新的云方案使用统计部分凝结，使用液态水位温和总水含量的联合高斯概率分布函数（PDF），标准偏差由湿Mellor-Yamada 2级湍流方案估计。它还采用了基于大涡模拟的改进闭合参数和随稳定性和湍流动能变化的修正混合长度。这些变化不仅可以更好地代表低层边界层云，而且还改善了大气边界层结构。垂直分辨率的敏感性实验表明，O（100-200米）的间隔是足够的，以代表良好的混合边界层与新的计划。新方案在相对较低的水平分辨率（约150公里）下表现良好，但在较高的水平分辨率（约50公里）下，海岸附近的逆温层变得更加强烈。皇家气象学会
An efficient grid‐scale cloud scheme for climate simulation is implemented in the atmospheric general circulation model for the Earth Simulator (AFES). The new cloud scheme uses statistical partial condensation using joint‐Gaussian probability distribution functions (PDFs) of the liquid water potential temperature and total water content, with standard deviations estimated by the moist Mellor–Yamada level‐2 turbulence scheme. It also adopts improved closure parameters based on large‐eddy simulations and a revised mixing length that varies with the stability and turbulent kinetic energy. These changes not only enable better representation of low‐level boundary layer clouds, but also improve the atmospheric boundary layer structure. Sensitivity experiments for vertical resolution suggest that O(100–200 m) intervals are adequate to represent well‐mixed boundary layers with the new scheme. The new scheme performs well at relatively low horizontal resolution (about 150 km), although inversion layers near the coast become more intense at a higher horizontal resolution (about 50 km). Copyright © 2010 Royal Meteorological Society