一次降水天气过程的GPS掩星资料在GSI同化系统中的应用  

Application and Experiment of GPS Radio Occultation Data in the NCEP GSI System in a Pricipitation Process

作　　者：郝民[1] 郭英华 马再忠 

机构地区：[1]中国气象局国家气象中心,北京100081 [2]美国国家大气研究中心,博耳德美国80301

出　　处：《高原气象》2010年第1期164-174,共11页Plateau Meteorology

基　　金：科技部国际科技合作项目(2006DFA21530)资助

摘　　要：为了探索全球定位卫星观测系统无线电掩星技术(Global Positioning System/Radio Occulta-tion,简称GPSRO)在业务数值预报模式中的应用效果,以美国NCEP(National Centers for Environ-mental Prediction)业务同化系统为平台,对有/无COSMIC(Constellation Observing System for Meteor-ology,Ionosphere and Climate)GPS无线电掩星观测资料进行了一次降水过程的详细的同化对比试验。试验中GPSRO观测算子主要采用了相对简单但计算省时的局地(Local)同化技术。该个例试验表明:COSMICGPS掩星观测对分析影响较大的地区是常规观测资料较稀缺地区(如洋面),因此在这些地区GPSRO资料可以被看作是对常规观测很好的补充。同时还注意到COSMIC GPS RO资料在对流层下层对湿度场分析和预报的影响显著,在对流层中上层对风场分析也产生正面影响。这证实GPS RO资料在业务数值天气预报中应用的有效性,为我国数值预报未来开展业务GPS掩星观测资料同化提供了有益的科学参考依据。In order to study the application of GPS/RO（Global Positioning System/Radio Occultation） technique on the operational numerical weather forecast model, the assimilation with and without COSMIC （Constellation Observing System for Meteorology, Ionosphere and Climate）GPS/RO data by using NCEP （National Center for Environmental Prediction, US） GSI（Grid point Statistical Interpolation） operational system were experimented and compared. In the experiments, the local refractivity operator was applied, which was relatively simple but could effectively save computational cost. The results showed that the GPS/RO observation data had obvious and positive impacts on the assimilation in the areas lacking ordinary observation data, such as areas of sea and plateau. The GPS/RO data were showed to be good supplements for the ordinary observation data in those areas. Further numerical experimental analysis showed that the assimilation with GPS/RO observations significantly improved the analysis for the fields of humidity, and the thus the rain-process forecasts, on the lower troposphere. There were also some positive impacts on wind analysis in the upper troposphere. Conclusively, these numerical simulation experiments further confirmed that the use of GPS/RO data effectively improved the assimilation and the process modeling. This work could be helpful in providing more useful references for the application of GPS/RO date on the operational assimilation and numerical weather prediction system.

关 键 词：GPS卫星观测 COSMIC GSI 

分 类 号：P414.4[天文地球—大气科学及气象学]