Variability in Coastal Flooding predictions due to forecast errors during Hurricane Arthur
Variability in Coastal Flooding predictions due to forecast errors during Hurricane Arthur
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DOI：
10.1016/j.coastaleng.2018.02.008
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发表时间：
2018-07-01
影响因子：
4.4
通讯作者：
Luettich, R. A.
中科院分区：
文献类型：
--
作者：
Cyriac, R.;Dietrich, J. C.;Luettich, R. A.
风暴潮预测模型依赖于风况的准确表示。在本文中，我们研究的敏感性浪涌预测预测的不确定性的轨道和强度的风暴（风暴强度量化的相关风场的功率耗散）。这项分析是使用飓风亚瑟（2014年）进行的，这是一场2级飓风，于2014年7月初沿北卡罗来纳州海岸沿着。在大型非结构化网格上进行了耦合水动力-波浪模型的后投模拟，以分析亚瑟沿着NC海岸线的浪涌影响。亚瑟的影响最好由风暴后数据同化的风产品与参数涡风提供了一个密切的近似。分析了亚瑟期间美国国家飓风中心（NHC）发布的预报公告所驱动的涌浪预报。NHC的风暴路径预测随着时间的推移而改善。然而，连续几次的预测都认为风暴的强度会有不切实际的增强。由于这些预报误差，当风暴接近登陆时，预报风速和水位的全球均方根误差会增加。的轨道和强度误差的浪涌预测的相对影响进行评估，通过替换预测风暴参数与最知名的风暴后信息亚瑟。在“恒定路径”分析中，亚瑟的风暴后确定的路径被用来代替不同气象局的路径预测，但每个公告都保留其大小和强度预测。在“恒定风暴强度”分析中，预测的风和压力参数被从风暴后分析中提取的相应参数所取代，而每个咨询保留其预测的风暴路径。我们观察到预测误差和风速预测之间有很强的相关性。然而，这些误差和预报水位之间的相关性很弱，这表明浅水沿海沃茨对气象强迫的非线性响应。
Storm surge prediction models rely on an accurate representation of the wind conditions. In this paper, we examine the sensitivity of surge predictions to forecast uncertainties in the track and strength of a storm (storm strength is quantified by the power dissipation of the associated wind field). This analysis is performed using Hurricane Arthur (2014), a Category 2 hurricane, which made landfall along the North Carolina (NC) coast in early July 2014. Hindcast simulations of a coupled hydrodynamic-wave model are performed on a large un-structured mesh to analyze the surge impact of Arthur along the NC coastline. The effects of Arthur are best represented by a post-storm data assimilated wind product with parametric vortex winds providing a close approximation. Surge predictions driven by forecast advisories issued by the National Hurricane Center (NHC) during Arthur are analyzed. The storm track predictions from the NHC improve over time. However, successive advisories predict an unrealistic increase in the storm's strength. Due to these forecast errors, the global root mean square errors of the predicted wind speeds and water levels increase as the storm approaches landfall. The relative impacts of the track and strength errors on the surge predictions are assessed by replacing forecast storm parameters with the best known post-storm information about Arthur. In a "constant track" analysis, Arthur's post storm determined track is used in place of the track predictions of the different advisories but each advisory retains its size and intensity predictions. In a "constant storm strength" analysis, forecast wind and pressure parameters are replaced by corresponding parameters extracted from the post storm analysis while each advisory retains its forecast storm track. We observe a strong correlation between the forecast errors and the wind speed predictions. However, the correlation between these errors and the forecast water levels is weak signifying a non-linear response of the shallow coastal waters to meteorological forcing.