Relative accuracy of HWRF reanalysis and a parametric wind model during the landfall of Hurricane Florence and the impacts on storm surge simulations
Relative accuracy of HWRF reanalysis and a parametric wind model during the landfall of Hurricane Florence and the impacts on storm surge simulations
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DOI：
10.1007/s11069-022-05702-3
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发表时间：
2022-11
期刊：
影响因子：
3.7
通讯作者：
M. Rahman;Yu Zhang;Lixin Lu;S. Moghimi;K. Hu;Ali Abdolali
中科院分区：
文献类型：
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作者：
M. Rahman;Yu Zhang;Lixin Lu;S. Moghimi;K. Hu;Ali Abdolali
风暴潮的预报和再分析依赖于参数热带气旋风场模式或数值天气模式再分析的风场和压力场，两者在登陆过程中都存在较大误差。本研究评估了2018年9月在卡罗莱纳州登陆的飓风佛罗伦萨的两组风场/压力场，并评估了两组模拟风场中的差异结构误差对由此驱动的风暴潮预测精度的影响。第一个集合是使用荷兰2010(H10)制作的，第二个集合是由NWS国家环境预测中心(NCEP)创建的飓风天气研究和预报(HWRF)再分析。每一种方法都使用在公共和商业平台收集的大型地面数据集进行验证，然后被用作输入，强制输入到2-D海岸水动力模型(Delft3D Flexual Mesh)，以产生卡罗莱纳海岸和主要声音的风暴潮。主要发现包括以下几点。首先，HWRF的风场总体上比基于H10的风暴外围风场更准确，尽管它们在分辨中心附近的高风速方面存在局限性。其次，将H10应用于佛罗伦萨的最佳轨迹数据，会在9月15日风暴减弱为热带低气压时错误地产生风速峰值。第三，HWRF风场在登陆后表现出逐渐的负偏差，这可能是由于模式在描述边界层过程方面的不足，以及登陆后缺乏地面产品的同化来补偿这些不足。第四，使用HWRF再分析作为Delft3D的强迫，可以得到更准确的峰值涌浪模拟，尽管在靠近路径中心的海岸线上对涌浪有严重的低估。Delft3D的峰值涌浪模拟在H10驱动时偏低，尽管H10模式在几个地点明显高估了地面风速。这种对比突出了分辨离中心更远的风场的重要性，以便准确地再现风暴潮和相关的沿海洪水。
Prediction and reanalysis of storm surge rely on wind and pressure fields from either parametric tropical cyclone wind models or numerical weather model reanalysis, and both are subject to large errors during landfall. This study assesses two sets of wind/pressure fields for Hurricane Florence that made landfall along the Carolinas in September 2018 and appraises the impacts of differential structural errors in the two suites of modeled wind fields on the predictive accuracy of storm surge driven thereby. The first set was produced using Holland 2010 (H10), and the second set is the Hurricane Weather Research and Forecasting (HWRF) reanalysis created by the NWS National Centers for Environmental Prediction (NCEP). Each is validated using a large surface data set collected at public and commercial platforms and then is used as input forcing to a 2-D coastal hydrodynamic model (Delft3D Flexible Mesh) to produce storm surge along the Carolina coasts and major sounds. Major findings include the following. First, wind fields from HWRF are overall more accurate than those based on H10 for the periphery of the storm, though they exhibit limitations in resolving high wind speeds near the center. Second, applying H10 to the best track data for Florence yields an erroneously spike in wind speed on September 15th when the storm reduced to a tropical depression. Third, HWRF wind fields exhibit a progressively negative bias after landfall, likely due to deficiencies of the model in representing boundary layer processes, and to the lack of assimilation of surface product after landfall for compensating for these deficiencies. Fourth, using HWRF reanalysis as the forcings to Delft3D yields more accurate peak surges simulations, though there is severe underestimation of surge along the shoreline close to the track center. The peak surge simulations by Delft3D are biased low when driven by H10, even though over several locations the H10 model clearly overpredicts surface wind speeds. This contrast highlights the importance of resolving wind fields further away from the center in order to accurately reproduce storm surge and associated coastal flooding.