变分资料同化中不同的变分求解方法

The different variational solutions review in variation data assimilation

在应用变分资料同化方法时面临着两方面的难题:一是背景场误差协方差矩阵的求逆问题;二是与背景场误差协方差矩阵相关的计算与存储问题。为了解决这两方面的问题,不同的求解方法便被提出来了。对主要的变分求解方法,包括增量法、运用空间滤波算子的变分分析法、预处理化法、物理空间统计分析法、谱统计插值法等进行了系统的回顾,对它们的优缺点进行了分析与讨论,并指出了变分资料同化中各种求解方法的适用条件。

There are two difficulties in variation data assimilation.The first is how to avoid inverting the background error covariance matrix.The second is how to handle the storage and computation related to the background error covariance matrix.All kinds of variation solution in variation data assimilation are put forward in order to settle the two problems above motioned.In this paper,the different variational solutions including incremental method,variational analysis using a filter,preconditioning control variable,physical-space statistical analysis,spectral statistical interpolation and so on are reviewed by the numbers.Then the advantage and disadvantage about the variation solution in variation data assimilation are analyzed and discussed in detail.