北京大学学报(自然科学版)

中尺度模式湍流参数化的比较研究

孙爱东1,徐玉貌2   

  1. 1北京大学地球物理学系,北京,100871;2南京大学大气科学系,南京,210093
  • 收稿日期:1999-06-03 出版日期:2000-05-20 发布日期:2000-05-20

The Comparison Study of Two Turbulence Parameterization in Meso-scale Numerical Weather Forecasting

SUN Aidong1, XU Yumao2   

  1. 1Geophysics Department, Peking University, Beijing, 100871; 2Atmospheric Science Department, Nanjing University, Nanjing, Jiangsu, 210093
  • Received:1999-06-03 Online:2000-05-20 Published:2000-05-20

摘要: 在中尺度区域模式MM4的基础上对其中的湍流参数化方法作了改进,尝试用非局地闭合方法代替局地 K 闭合处理湍流扩散问题,分别以原MM4中有云和无云的水份处理方案作为控制方案。比较的结果证明,非局地方法若要应用于实际预报,还需要作较大的改进,主要是针对决定过渡矩阵的非局地混合潜势。目前的过渡矩阵表达方式使物理量在空间的分布不合理地过于均匀,造成了降水量的减少。

关键词: 中尺度模式, 湍流参数化, 非局地闭合

Abstract: The non-local turbulence parameterization, i.e., transilient theory was used in the host model MM4 to simulate the turbulent activities of the atmosphere. The control models are the standard MM4 using the Blackadar high resolution boundary scheme, the bulk boundary scheme, the KUO cumulus parameterization scheme and explicit clouds. Results of comparison indicate that although some oversea study of the transilient theory succeeded in a degree, if the transilient theory is to be used in model MM4, substantial improvement of the expression of the vertical mixing potential is necessary, or an empirical filter should be applied to ameliorate the result of forecasting. Although the location of rainfall is the same as the host model, the expression used in many researches had the tendency of over-mixing, leading to the decreasing of rainfall.

Key words: meso-scale model, turbulence parameterization, turbulence kinematic energy, non-local theory

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