Bayesian image analysis and the disaggregation of rainfall

The applicability of meteorological general circulation models (GCMs) is li mited by their spatial resolution. In this paper, a method is developed for improving the resolution of GCM-generated rainfall fields, using ideas fro m Bayesian image analysis to improve the resolution of the binary wet-dry i mage. This approach incorporates both the spatial and temporal memory of th e rainfall held and can be adapted to utilize any available physical inform ation. The method is illustrated using data from a network of weather radar stations in Arkansas, and some informal diagnostic procedures are develope d for assessing the adequacy of the underlying model.