初值中云变量对T213预报性能的影响  

Impacts of the Cloud Initialization on T213 Forecasting Performances

作　　者：管成功[1] 陈起英[1] 王娟 佟华 

机构地区：[1]国家气象中心 [2]黑龙江省嫩江县气象局,嫩江161400

出　　处：《应用气象学报》2007年第5期594-600,共7页Journal of Applied Meteorological Science

摘　　要：采用云变量自由变化的方案,在国家气象中心全球业务模式T213L31的初始场中增加有关云变量的信息,通过2005年6—8月和2015年12月—2006年2月各3个月的连续滚动对比试验的统计分析和个例预报分析,研究探讨了全球模式初值中增加云变量对模式预报性能的影响。初步研究结果表明:采用自由变化的方案在初值场中增加云的信息,使模式能够较为合理地描述出模式预报初期与云相关变量分布和变化特征,降低了spin-up现象对模式前期降水预报能力的影响,同时对500 hPa形势场预报也有一定程度提高。Cloud variables such as cloud water, cloud ice and cloud cover are not treated in most operational data objective analyses and initialization schemes. While cloud variations are used as prognostic variables in a forecast model, they are necessary to be defined at initial time. The common method is to set cloud variations to zero at the initial time in the initial field, and some time of several hours are needed by the forecast model in doing spin-up at the beginning of the run, which is sure to affect the forecasting capabilities such as precipitation and patterns and so on. The cloud free variation scheme is adopted to realize the adding of cloud variations information to the model initial fields of T213L31, the operational global model, then both a statistic analysis of a 3-month continuous running of test and operation schemes and a case study are carried out. In order to testify that the cloud free variation scheme does not foil the balance between dynamic and thermal variances at the start of model forecast, the stabilities of the model are checked and confirmed firstly by means of analyses on kinetic energy, tempera- ture, and so on by long time integration. A synoptic case study, which happens on June 18--19, 2005, shows that with cloud information including cloud water, cloud ice and cloud cover being added to the initial model field, the spin-up phenomenon disappears which always occurs at the starting period of forecasting, and often exists for 12 to 18 hours or longer, before the cloud free scheme being added in the modeling system. And the characteristics of distribution and variation of cloud-related variables can be more reasonably dcl,icted by the model than the operational one so that the improvement of the model forecasting performance is led to especially in the short-time precipitation prediction. The 3-month continuous parallel experiment in winter and summer respectively are done together with corresponding operational ones. The results based on summer 3-month statistic analyses show that pos

关 键 词：云变量 初值 降水 

分 类 号：P456[天文地球—大气科学及气象学]