时间滞后与奇异向量初值生成方法的比较试验

THE COMPARISON EXPERIMENTS OF SV AND LAF INITIAL PERTURBATION TECHNIQUES USED AT THE NMC ENSEMBLE PREDICTION SYSTEM

简单介绍了国家气象中心基于奇异向量初值生成方法的神威集合预报准业务系统 ,它主要包括资料的前处理、客观分析、预报模式、初值扰动的生成、后处理、产品制作和系统监控七个部分 ,共有 3 2个成员。提出了 1 2个成员的时间滞后法集合预报系统的实施方案 ,并与奇异向量法进行了对比试验。结果表明 ,不论是距平相关系数还是均方根误差 。

The Ensemble Prediction System (EPS) at NMC is briefly described. It mainly includes such seven parts as the data pre-processing, optimal interpolation analysis, the forecasting model (T106L19), the computation of initial perturbations based on singular vectors, post-processing, the generation of ensemble products and the system monitoring. The configuration of EPS compromises one control forecast started from the unperturbed analysis and 31 perturbed forecasts started from the perturbed analysis. Then the lagged average forecasting (LAF) scheme with 12 members is proposed and implemented at the SW-1 computer. The comparison experiments are conducted by using different initial perturbation techniques. One is SV (singular vectors), the other is LAF. The results show that the performance of SV is better than that of LAF in most of the verified regions and lead times, both for the anomaly correlation coefficients and the root mean square errors.