Approximate iterative methods for variational data assimilation

摘要

The problem of four-dimensional variational data assimilation can be considered as a non-linear least squares problem. A common method for solving it is equivalent to a Gauss-Newton method. However, approximations must be made in order to solve the problem efficiently. In this paper we examine two approximations to the Gauss-Newton method and their effect on the data assimilation problem.