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投稿时间:2011-01-12 修订日期:2011-02-20
投稿时间:2011-01-12 修订日期:2011-02-20
中文摘要: 目前我国的T213全球集合预报系统采用BGM初值扰动方案,没有考虑模式扰动方法,在技术上滞后于国际先进数值中心的集合预报系统。本文参考ECMWF的模式扰动方法,设计了我国T213全球集合预报系统的物理过程随机扰动方法,并对2008年7月20—31日进行了集合预报批量试验。试验结果表明:T213全球中期数值预报模式对物理过程随机扰动很敏感,对物理过程扰动后,模式物理量的预报情况发生变化,且这种变化随着积分时间增长而迅速扩大。在水平方向上主要表现为南北半球中高纬度地区较赤道地区更敏感,在垂直方向上,表征大尺度运动特征的物理量(如位势高度、温度、风速等)在南北半球中高纬度地区的低层到高层都很敏感,尤以300 hPa最为明显,垂直速度、散度等物理量在赤道地区也非常敏感。多初值集合预报加入物理过程随机扰动后,集合平均均方根误差在积分后期略有改善,对降水预报水平也有较为明显的提高,这表明物理过程随机扰动方法具有较好的业务应用前景。
中文关键词: T213, 集合预报, 物理过程随机扰动, 检验评估
Abstract:The CMA T213 global ensemble prediction system using BGM initial perturbation scheme has not considered model perturbation thus lags behind the ensemble forecasting system of international advanced technical centers. This paper referring to the ECMWF model perturbation method, designs a T213 global ensemble prediction system stochastic physics perturbation method, and conducts ensemble prediction tests in 20-31 July 2008. The results show that, the T213 global ensemble prediction system is very sensitive to stochastic physics perturbation. This is because after physics perturbed, predictor variables change significantly, and the changes expand rapidly with the integration time of growth. In the horizontal direction, the middle and high latitudes are more sensitive than the equatorial regions. In the vertical direction, the variables characterizing the large scale movements, such as geopotential height, temperature, and wind speed are very sensitive from low to upper levels, and the most sensitive is at 300 hPa, in the middle and high latitudes of north and south hemispheres; while vertical velocity, divergence and other physical variables in the equatorial region are also very sensitive. After the multiple initial condition ensemble added to the stochastic physics perturbations, the spread and RMSE of ensemble mean are improved slightly in the late term of integration, while the improvement of the precipitation forecast is significant, which indicates the prospect of operation to the stochastic physics perturbation is good. The next step will be more test assessments, and the operations of the stochastic physics perturbation are as early as possible to shorten the distance between China and the international advanced technology in the ensemble.
keywords: T213 model, ensemble prediction, stochastic physics perturbation, verification and evaluation
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基金项目:国家科技支撑计划(项目编号:2009BAC51B00)资助
引用文本:
任志杰,陈静,田华,2011.T213全球集合预报系统物理过程随机扰动方法研究[J].气象,37(9):1049-1059.
Ren Zhijie,Chen Jing,Tian Hua,2011.Research on T213 Ensemble Prediction System Stochastic Physics Perturbation[J].Meteor Mon,37(9):1049-1059.
任志杰,陈静,田华,2011.T213全球集合预报系统物理过程随机扰动方法研究[J].气象,37(9):1049-1059.
Ren Zhijie,Chen Jing,Tian Hua,2011.Research on T213 Ensemble Prediction System Stochastic Physics Perturbation[J].Meteor Mon,37(9):1049-1059.