A study of three finite-difference schemes and their role in asynoptic meteorological data assimilation

An investigation was conducted concerning the response of various finite-difference schemes to the insertion of unweighted data. A simple barotropic model was employed as a forecast model. The Mintz-Arakawa two-level general circulation model was used as a source of data. The schemes tested include a Shuman scheme employing centered time differences and 9-point spatial smoothing. Two other schemes investigated were a Matsuno-TASU scheme and a semiimplicit scheme similar to one proposed by McPherson (1971).