预报方程差分格式的构造方法

ON THE METHOD OF SETTING UP DIFFERENCE SCHEME FOR THE WEATHER FORECASTING EQUATION

中文摘要:

      本文用差分模拟绝对涡度守恒定律,构成正压涡度方程的两类差分格式:积分守恒型格式和相当于准拉格朗日型格式。前一类型格式的显式部分是条件稳定的,隐式部分是无条件稳定的。后者至为无条件稳定的显式格式,可以依据实际需要和可能,来放大无条件稳定格式的时间步长。本文还根据格式的计算要求,讨论了“风”场的计算和平滑问题,以及差分方程的边、初条件(计算边、初条件)的给法。并通过理想场计算和实例预报,检验了几种显式格式的计算效果。

英文摘要:

      The two types of difference schemes, the integrated conservative type and the equivalent semi-Lagrangian type, based on the analogue to the principle of conservation of the absolute vorticity by the finite difference, are presented. In the first type, the explicit scheme is conditionally stable and the implicit scheme non-conditionally stable. The second type is the non-conditionally stable explicit scheme. As a numerical test of the present schemes, equations(7),centred fimite difference(Ⅲ') and(28, 27) in the [1] were used in solving geostrophic barotropic model. Table 2 shows the examples of the calculate results.