Explaining Rogue Waves in the Ocean Through Observations and Modelling

通过观测和建模解释海洋中的异常波浪

• 批准号: 2595418
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2595418
• 关键词: Explaining; Rogue; Waves; Ocean; Through

Rogue waves are large, unexpected surface waves on the ocean that can cause catastrophic damage to offshore structures and vessels. These 'freak' or 'monster' waves are suspected to have capsized hundreds of ocean-going vessels and resulted in an unfortunate loss of life. A range of proposed explanations exist for the formation of rogue wave events including the effect of localised currents, abrupt depth transitions, modulation instability, dispersive (and directional) focusing enhanced by second-order bound nonlinearity, and Greenspan resonance through interaction with atmospheric convective storms. All are able to create rogue waves given the right set of theoretical conditions. However, debate is ongoing as to the dominant mechanism(s) for rogue wave formation in real seas.This project aims to make significant progress in our understanding for real ocean settings, primarily through the generation and analysis of numerical models created to assess regions (and time scales), where rogue wave observations have been made. This will be supported by a novel analysis of unexploited ocean datasets that contain rogue wave measurements (or indirectly hint at their occurrence).A suggested route to achieving the project aims is to develop spectral wave models to hindcast the wave conditions in the region of observed rogue wave events. The spectral conditions can then be used, in combination with local bathymetry, to drive a phase-resolved model (e.g. nonlinear potential flow) over a localised region. The statistical and spectral analysis of the resulting conditions can be used to identify a) did the model capture an enhanced likelihood of rogue wave events? and b) if so, what is the dominant cause?If the approach is successful in identifying the dominant cause(s) of rogue waves in oceans, then this will make significant advances in our understanding of rogue wave formation in real seas in addition to validating the methodology developed throughout the project for their assessment. The implications of these findings have the potential to be fundamentally significant with wide-ranging practical implications. With improved understanding, appropriate extreme 'design' conditions can be defined for the de-risking of offshore vessels and structures, and if locations and/or time scales can be identified which have an increased risk potential, these can potentially be avoided. Consequently, the results have the potential to reduce capital loss as well as loss of life.In addition, the work underpinning this project has the potential to answer a range of further unanswered additional research questions surrounding rogue waves. Key future research questions may include:1. Could these rogue waves (or the increased likelihood of) have been predicted?2. How spatially localised is the increased likelihood of rogue wave events?3. Using the developed framework, is it possible to identify 'ideal' (worst-case) input conditions for creating rogue wave events?4. Will rogue waves will become more common in the future climate? To address this question, we could produce a dataset of extreme waves from an ensemble of wave models forced by winds from climate projections.

狂暴波浪是海洋上意想不到的巨大表面波浪，可能对近海结构和船只造成灾难性损坏。这些“怪异”或“怪物”的波浪被怀疑导致数百艘远洋船只倾覆，并造成不幸的人员伤亡。对于异常波事件的形成存在一系列提出的解释，包括局域电流的影响、突然的深度转变、调制不稳定性、二阶束缚非线性增强的色散（和方向）聚焦，以及通过与大气对流风暴相互作用的格林斯潘共振。在适当的理论条件下，所有人都能够创造出异常的波浪。然而，关于真实海洋中异常波浪形成的主要机制的争论仍在继续。该项目旨在主要通过生成和分析用于评估区域的数值模型，在我们对真实海洋环境的理解方面取得重大进展（和时间尺度），其中进行了异常波观测。这将得到对包含异常波浪测量（或间接暗示其发生）的未开发海洋数据集的新颖分析的支持。实现该项目目标的建议途径是开发光谱波浪模型来预测观测区域的波浪状况流氓浪潮事件。然后可以使用光谱条件与局部测深相结合，在局部区域上驱动相位解析模型（例如非线性势流）。对所得条件的统计和频谱分析可用于识别：a) 模型是否捕获了异常波浪事件的可能性增加？ b) 如果是，那么主要原因是什么？如果该方法成功地识别了海洋中异常波浪的主要原因，那么这将在我们对真实海洋中异常波浪形成的理解方面取得重大进展验证整个项目中开发的评估方法。这些发现的影响可能具有根本性意义，具有广泛的实际意义。随着理解的加深，可以定义适当的极端“设计”条件来降低近海船舶和结构的风险，并且如果可以识别出潜在风险增加的位置和/或时间尺度，则可以避免这些情况。因此，研究结果有可能减少资本损失和生命损失。此外，支持该项目的工作有可能回答一系列有关异常波浪的进一步未解答的其他研究问题。未来的关键研究问题可能包括：1．这些异常的波浪（或增加的可能性）是否可以被预测到？2。异常海浪事件增加的可能性在空间上的局部性如何？3.使用开发的框架，是否可以识别创建异常波浪事件的“理想”（最坏情况）输入条件？4。在未来的气候中，狂暴的波浪会变得更加普遍吗？为了解决这个问题，我们可以根据气候预测中的风所产生的波浪模型集合来生成极端波浪的数据集。