北半球七层初始方程谱模式在制作有限区数值预报中的应用

本文提出了一种以北半球七层初始方程谱模式为基本模型的有限区加密方法。这个方法利用谱模式的特点对初始场展开和时间积分中的非线性项计算增加了一些处理，使所选有限区范围内（50°—140°E，20°—60°N）的分辨率有所提高，使模式能在制作出北半球较低分辨率（5°×5°）预报的同时，还能制作出有限区较高分辨率（2.5°×2.5°）的预报。用ECMWF分析资料进行了24小时和48小时预报对比试验，得到了较好的结果。

The Application of Seven-level Primitive Equation Spectral Model to Numerical Forecasts for a Limited Area

In this paper, a higher resolution model for a limited area based on the Northern Hemisphere spectral model is presented. By applying the characteristics of the spectral model, some new treatments have been added on it for the expansion of initial meteorological field and for the calculation of nonlinear terms in the time integration in this model so that the initial meteorological field and the results of integration can be more accurate in a limited area (50o—140oE, 20—60oN). This model may be used to prepare for both the forecast with lower resolution (5o×5o) in the Northern Hemisphere and the forecast for a limited area with higher resolution (2.5o×2.5o) in the same time. The control experiments for 24 and 48 hours forecasts have been made by using data analysed by ECMWF and the better results have been obtained