Designment Of Adjoint-model Assimilation System And Its Application

As an efficient approach to improve the accuracy of numerical weather prediction (NWP) .Four-dimensional Adjoint-model Variational Assimilation is focused on by national experts. In this text the technique of adjoint codes which is a basic means of constructing adjoint model and the adoptions of weight, scaling, descend arithmetic are introduced amply. Furthermore data assimilation experimentations are conducted with MM5 Adjoint-model Assimilation System made by adjoint code. With a case of heavy rainfall taken place in OOh 18th to ooh 19th June , conventional observation data are taken in Assimilation System. The result indicate that MM5 Adjoint-model Assimilation System can improve the quality of initial field and the forecast of model about rainfall and other weather factors. On this basis MM5 Adjoint-model Assimilation System is advanced to assimilate terrain data of MMS.The results of experimentations with different terrain data indicate that the terrain error is modified well and truly by MM5 Adjoint-model Assimilation System. The terrain assimilated become more harmonious with MM5 and its resolution is well match to the resolution of initial observation field. A new way about how to widely apply assimilation system is offered in this text.