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一、引 言 自从数值预报成功地发展以来,高频波动的存在一直是被研究的主要问题之一,并且各种初始化方法和积分方法都得到了发展。作为一种初始化方法Lynch(1984)介绍了拉普拉斯变换(LT)。对于一般的非线性方程组,由于其非线性项应用LT方法是极其困难的。但是这些项的变化缓慢,允许我们将其视为常数。转换方程是隐式的,为了取得需要的滤波解,必需引进迭代的初始化格式。LT方法不仅应用于初始化,而且Van Isacker和Struy-laert(1985)还将它应用到正压模式方程的积分上。这种具有永久滤波性质方法所允许时间步长的优点比其它积分方法大得多。
I. INTRODUCTION Since the successful development of numerical prediction, the existence of high frequency fluctuations has been one of the major issues studied, and various initialization methods and integration methods have been developed. As an initialization method, Lynch (1984) introduced Laplace Transform (LT). For a general nonlinear system of equations, it is extremely difficult to apply the LT method because of its non-linearity. But these changes are slow, allowing us to treat them as constants. The conversion equation is implicit, in order to obtain the necessary filtering solution, it is necessary to introduce an iterative initialization format. The LT method applies not only to initialization, but also to Van Isacker and Struy-laert (1985) for applying it to the integral of a positive pressure mode equation. The advantage of this time-step allowed by this method of perpetual filtering is much greater than other integration methods.