DEVELOPMENT OF A VARIABLE-RESOLUTION GLOBAL DATA ASSIMILATION SYSTEM

M. D. Tsyrulnikov, M. A. Tolstykh, A. N. Bagrov, and R. B. Zaripov

The paper presents a data assimilation system (DAS) based on the global semi-Lagrangian variable-resolution forecast model and the optimum-interpolation objective analysis scheme. The distinctive features of the DAS are the sequential assimilation of various types of observations and data assimilation using the incremental approach. The assimilation methodology, the blocks of the system, and implementation issues are described. The DAS (in the constant-resolution mode) demonstrates stable performance on the one-month archive of observations for February 2000. The accuracies of 6-h forecasts used as a first guess in the analysis and also of 72-h forecasts are indicated. The results are indicative of the efficiency of the proposed methodology and implementation.