A Regional Grid Three-Dimensional Variational Analysis Scheme-Basic Construction and Preliminary Tests
一种区域格点三维变分分析方案--基本框架和初步试验

The basic construction of a regional grid three-dimensional variational (3D-Var) analysis scheme is described. To deal with the covariance matrix of background errors B, three skills are used. These skills include choosing suitable analysis variables to simplify computations of matrix B, doing a variable transformation to avoid matrix inversion and separating univariate correlation matrix into horizontal and vertical parts to use recursive filter instead of matrix computations in the horizontal. Then 3D-Var analyses can be carried out. This scheme is tested through a single observation, ideal distributed observations and real observation data. The results are very satisfying.