一次登陆台风的集合预报试验  

AN ENSEMBLE FORECAST EXPERIMENT OF A LANDING TYPHOON

作　　者：谭燕 梁旭东[1] 

机构地区：[1]中国气象局上海台风研究所,中国气象局台风预报技术重点开放实验室,上海200030

出　　处：《热带气象学报》2010年第4期401-408,共8页Journal of Tropical Meteorology

基　　金：国家重点基础研究发展计划资助(2009CB421500);上海台风研究所“台风路径集合预报技术的研究及初步应用”(2008ST13);上海气象局“基于台风集合预报系统性能评估的偏差订正算子的研究”(QM200803)共同资助

摘　　要：选取0713号台风"韦帕"临近登陆过程为试验个例,在GRAPES_TCM模式基础上,采用增长模繁殖法(BGM)分别对台风涡旋场和环境场进行扰动来构造集合成员,进行集合预报,作为对台风数值预报方法的一种新的尝试。试验结果表明:通过BGM的动力调整后,成员间体现出不同的扰动形态,使得在后期的预报中产生合适的集合离散度。在台风登陆前后,大尺度平均位势高度场和风场以及集合系统的离散度均发生了明显的变化,可以看到大尺度环境场引导作用的差异使得成员间对台风路径的预报各不相同,体现了预报的不确定性。对路径预报而言,简单的算术平均并没有优于控制预报的表现,但通过聚类分析后,可以提高集合产品的使用效率。从中可以得到一点启发:怎样利用集合系统提供的大量信息值得进一步思考,聚类分析不失为一种改善集合预报产品利用效率的有效方法。Based on the Global/Regional Assimilation and PrEdiction System for tropical cyclones （GRAPES-TC） model, an ensemble forecast experiment was performed in which Typhoon Wipha was selected for the period just prior to landing. The breeding of growing modes （BGM） method was used to perturb the initial conditions of the vortex field and the environment field, respectively. The results indicate that each member has a different initial status by BGM processing and shows reasonable spread among members along with the forecast phase. Changes in the large-scale field, the thermodynamic structure and the spread among members have taken place when Wipha makes landfall. The steering effect of the large-scale field and the interaction between the thermodynamics and the dynamics result in different tracks of the members. Meanwhile, the forecast uncertainty is increased. Totally, the ensemble mean does not perform as well as the control forecast, but the cluster mean indicates some useful information and some of them perform better than the control; the track error is 34 km for 24 h forecast, 153 km for 48 h forecast, and 191 km for 66 h forecast. Meanwhile, the strike probability chart describes the forecast uncertainty quantitatively.

关 键 词：登陆台风 集合预报 增长模繁殖法 聚类分析 

分 类 号：P456.7[天文地球—大气科学及气象学]