HWRF Based Ensemble Prediction System Using Perturbations from GEFS and Stochastic Convective Trigger Function
HWRF Based Ensemble Prediction System Using Perturbations from GEFS and Stochastic Convective Trigger Function
复制标题
使用 GEFS 扰动和随机对流触发函数的基于 HWRF 的集合预测系统
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Weiguo Wang
中科院分区：
文献类型：
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作者：
Zhan Zhang;V. Tallapragada;C. Kieu;S. Trahan;Weiguo Wang
本文介绍了美国国家环境预测中心（NCEP）环境模拟中心（EMC）飓风天气研究与预报（HWRF）模式的集成预报系统（EPS），并对其进行了评价。HWRF-EPS考虑了与初始/边界条件和模式物理相关的两个主要不确定性来源：1)利用NCEP全球集合预报系统（GEFS）的大尺度场；2)随机扰动积云对流参数化方案中的对流触发函数。对2011-2012年北大西洋飓风季节的验证表明，HWRF-EPS在路径和强度预报误差的所有提前时间都优于确定性版本。研究和分析了统计特征，以证明HWRF-EPS的有效性和鲁棒性。HWRF-EPS中路径和强度的集合分布与预报误差之间的关系表明，当分布具有中等低的值时，其作为预报误差的预测因子可能更有用。秩直方图分析表明，除了确定性预报的系统误差外，HWRF-EPS在路径预报和强度预报中均具有较好的分散性。与2012年飓风季的顶级飞行模型进一步比较，HWRF-EPS的路径和强度预测得到了改进。
ABSTRACT In this study, an ensemble prediction system (EPS) for the operational Hurricane Weather Research and Forecast (HWRF) model at the Environmental Modeling Center (EMC) of National Centers for Environmental Prediction (NCEP) is introduced and evaluated. The HWRF-EPS takes into account two main sources of uncertainties related to the initial/boundary conditions and the model physics by 1) using the large scale fields from NCEP Global Ensemble Forecast System (GEFS); and 2) stochastically perturbing the convective trigger function in the cumulus convection parameterization scheme. Verification for the 2011-2012 North Atlantic hurricane seasons shows that HWRF-EPS outperforms its deterministic versions at all lead times for both track and intensity forecast errors. Statistical characteristics are investigated and analyzed to demonstrate the effectiveness and robustness of the HWRF-EPS. The relationship between ensemble spread and forecast error for track and intensity in the HWRF-EPS indicated that the spread is likely more useful as a predictor of forecast error when it has moderately low values. Rank histogram analysis shows that the HWRF-EPS is well dispersed in both track and intensity forecasts except for the systematic errors inherited from the deterministic version. Further comparison with 2012 hurricane season’s top-flight models shows improved track and intensity forecasts from the HWRF-EPS.