The impact of cloud motion wind data on numerical simulation of wind field in the sea area of Eastern Asia

In order to explore the impact of cloud motion wind(CMW) data on the numerical simulation of wind fields from upper to lower levels in the sea area of eastern asia,the CMW data retrieved from infrared and water vapor channels of Japan GMS satellite from late June to early July in 1999 is adopted. First the quality of the CMW data is evaluated and the results indicate that the root square meanerror and bias of the CMW's u &v components are in the permmited ranges. Then five different four assimilation simulation experiments are performed for each of ten cases. Mutifold comparisions between the assimilation experiments and non-assimilation ones indicate that after initial 12 h assimilation of regular upper air and surface obser vation and CMW data,it is much evident that the quality of the simulation results is promoted. The maximum difference between assimilation experiments and control ones occurs at 12 h which is also the end hour of assimilation,after this it minishes along with the increasing simulation time. But during 24~36 h the effects that the assimilation experiments are better than the control ones begin to increase,after 36 h it dropsagain. Because of absence of regular observation in sea area,it is impossible to implement observation assimilation on sea part and it is certain that this will influence the simulation quality of sea part. Experiments indicate that the CMW data improves u & v wind fields mainly on the upper troposphere(300~200 hPa) and it has lillte impacton middle-lowlevel,which is consistent with the fact that the CMW data distributes on upper levels. The performance of the CMW assimilation experiments using the quality control is,to some extent,better than that of ones not usingit.