Stochastic representation of model uncertainties in the ECMWF Ensemble Prediction System
Stochastic representation of model uncertainties in the ECMWF Ensemble Prediction System
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DOI：
10.1256/smsqj.56005
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发表时间：
1999-10-01
影响因子：
8.9
通讯作者：
Palmer, TN
中科院分区：
文献类型：
--
作者：
Buizza, R;Miller, M;Palmer, TN
随机误差与参数化的物理过程（“随机物理”）的随机表示，其影响在欧洲中期天气预报中心包围预测系统（ECMWF EPS）进行了讨论。与物理参数化相关的模型随机误差通过将总参数化趋势乘以从0.5和1.5之间的均匀分布中采样的随机数来模拟。描述了一些诊断方法，并选择了参数。结果表明，该方案增加了集合的传播，提高了降水等天气参数的概率预报能力。随机参数的选择是为了操作实现。该计划已于1998年10月21日在ECMWF EPS中成功实施。
A stochastic representation of random error associated with parametrized physical processes ('stochastic physics') is described, and its impact in the European Centre for Medium-Range Weather Forecasts Ensemble Prediction System (ECMWF EPS) is discussed. Model random errors associated with physical parametrizations are simulated by multiplying the total parametrized tendencies by a random number sampled from a uniform distribution between 0.5 and 1.5. A number of diagnostics are described and a choice of parameters is made. It is shown how the scheme increases the spread of the ensemble, and improves the skill of the probabilistic prediction of weather parameters such as precipitation. A choice of stochastic parameters is made for operational implementation. The scheme was implemented successfully in the operational ECMWF EPS on 21 October 1998.