Atmospheric Data Assimilation and Quality Control

In this paper we discuss the basic physics of the atmospheric data assimilation problem, in order to understand the important factors to be considered in its mathematical solution. The key mathematical technique, the optimal combination of information, is also approached from its Bayesian basics. Much of this is based on earlier papers (e.g. Lorenc, 1986). The novelty of this paper is its bringing together of these in a simple didactic form, following the agreed notation of Ide et al. (1997), with very simple examples to aid in the physical interpretation of the analysis equations.