非线性正规模初值化原则在有限区模式的实现

本文在普遍情况下导出了与非线性正规模初值化方法等价的、用模式变量表达的初值化准则与运算迭代公式.由于模式的正规模态在初值化计算中不明显地出现,故本文的结果对于正规模态难以求得的有限区模式的初值化有重要意义_试验实例表明,按本文的方案作初值处理,对于消除初值中的不平衡是十分有效的.

Initialization of Limited Area Model Based on the Principle of Nonlinear Normal Mode Initialization

Two general conditions of initialization for limited area model and their corresponding iterative computational formulae are derived in this paper. These conditions are equivalent to those of nonlinear normal mode initialization, but totally expressed in terms of the model variables. The fact that the normal modes of the model do not appear in those formulae makes it easy to perform in any regional model, of which the normal modes are usually difficult to derive. This proposed initialization scheme is applied to the two numerical prediction models. The results have proven that this scheme can effectively suppress the unwanted high frequency gravitational oscillation due to imbalance existing in the initial data .