Large-Scale Edge Waves Generated by Hurricane Landfall

飓风登陆产生的大规模边缘波

• 批准号: 0752059
• 负责人: Alexander Yankovsky
• 金额: $ 23.13万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0752059&HistoricalAwards=false
• 关键词: Large; Scale; Edge; Waves; Generated; Large; Scale; Edge; Waves; Generated

Intellectual merit:The hurricane-induced surge and flooding in the coastal areas is an important societal problem. Severe flooding outside the immediate landfall area and a few hours after the landfall can be caused by a freely propagating wave pulse. The cases indeed occurred in the past. The observations of the storm surge induced by Hurricane Wilma landfall on the West Coast of Florida on October 24, 2005 revealed a formation of a wave pulse as Wilma moved inland and the surge was no longer sustained by the wind forcing. The height of the wave pulse exceeded 1.5 m in de-tided sea level data, but it was somewhat obscured in the surge measurements because of its propagating during the low tide. The duration of this wave pulse was ~6 hrs and the propagation speed varied within a range of 10-25 m s-1 indicating an evolution process of the initial disturbance. The wave pulse is identified as an edge wave with large spatial and temporal scales. Such relatively short-lasting waves induced by a hurricane on the continental shelf were not reported before. Most likely, they escaped detection, because a sparse spatial resolution in the standard observational network maintained by NOAA and USGS cannot resolve their phase propagation. Instead, the previous studies were focused on lower-frequency coastally trapped waves (CTW) with periods comparable to or longer than the inertial, which were thought to be prevailing wave modes generated by tropical cyclones. This project will investigate the generation and alongshore evolution of the hurricane-induced edge waves by means of process-oriented numerical modeling. More specifically, the following questions will be addressed: - What are the most favorable conditions for the edge wave generation by a hurricane landfall? The roles of the hurricane size, strength, translation speed and trajectory, as well as the role of shelf topography, will be delineated. - What topographic forms induce the local amplification of the edge waves? The effects of large topographic variations (widening/narrowing shelf, bending coastline, etc.) and smaller features (inlets, estuaries, capes, etc.) will systematically be studied. - What are the mechanisms of the edge wave dissipation? Is the dissipation mostly related with the bottom friction or with the offshore energy radiation? Broader impacts:The results of the project will have applications to national and regional security in such areas as hazard mitigation, disaster prevention, and the development of early warning systems. The results will also be important for coastal zone management and protection, as well as for maritime operations. One graduate student will be supported by this project.

知识分子的优点：飓风引起的沿海地区的激增和洪水是一个重要的社会问题。立即登陆区域以外的严重洪水和登陆后的几个小时，可能是由自由传播的波脉冲引起的。案件确实发生在过去。 2005年10月24日，佛罗里达州西海岸的飓风威尔玛登陆引起的风暴潮的观察结果表明，随着威尔玛向内陆移动，波脉冲的形成，不再因风力强迫而维持。在去偏移的海平面数据中，波脉冲的高度超过了1.5 m，但由于在潮汐中的传播，它在涌动测量中有些遮盖。该波脉冲的持续时间约为6小时，传播速度在10-25 m S-1的范围内变化，表明初始干扰的进化过程。波脉冲被识别为具有较大空间和时间尺度的边缘波。以前没有报道过飓风在大陆架上引起的这种相对较短的波浪。他们最有可能逃脱了检测，因为NOAA和USGS维护的标准观察网络中稀疏的空间分辨率无法解决其相位传播。取而代之的是，先前的研究集中在低频捕获波（CTW）上，其周期与惯性相当或更长，而惯性被认为是由热带气旋产生的波浪模式。该项目将通过面向过程的数值建模来研究飓风诱导的边缘波的产生和沿岸。更具体地说，将解决以下问题： - 飓风登陆的边缘生成最有利的条件是什么？飓风规模，强度，翻译速度和轨迹以及货架地形的作用的作用将被描述。 - 哪种地形形式诱导边缘波的局部扩增？大型地形变化（扩大/狭窄的架子，弯曲海岸线等）以及较小的特征（入口，河口，披肩等）的影响将被系统地研究。 - 边缘耗散的机制是什么？耗散主要与底部摩擦或离岸能量辐射有关吗？更广泛的影响：该项目的结果将在诸如缓解危险，预防灾害和预警系统开发等领域的国家和地区安全申请。结果对于沿海地区的管理和保护以及海事行动也将很重要。该项目将为一名研究生提供支持。