Schemes and Applications of Grapes Model Standard Initialization

The designed schemes and programmed structures of the GRAPES model standard initialization (SI) system are introduced, with analysis of the initial fields from three schemes. Results indicate that fields of horizontal winds, temperatures and potential temperatures are not very sensitive to the precision of the interpolation scheme selected in sharp contrast to the geopotential field and Exner function for pressure that are sensitive to the accuracy of vertical interpolation. For generating model variables Scheme I is poorer compared to the others except its fast computational speed, but applicable to the model domain with smaller terrain gradient; either Schemes II or III can be chosen for use according to requirements. The SI system has its own primary functions, apart from which requirement-specific option of the system-provided regions, resolutions, number of vertical layers, and horizontal/vertical interpolation techniques given by the flexible designed programs can be made to satisfying the requirements of initial values, thereby facilitating the model development, research and experiment.