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Can rogue waves be predicted using characteristic wave parameters?

Cattrell, A. D.; Srokosz, M.; Moat, B. I. ORCID: https://orcid.org/0000-0001-8676-7779; Marsh, R.. 2018 Can rogue waves be predicted using characteristic wave parameters? Journal of Geophysical Research: Oceans, 123 (8). 5624-5636. https://doi.org/10.1029/2018JC013958

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Abstract/Summary

Rogue waves are ocean surface waves larger than the surrounding sea that can pose a danger to ships and offshore structures. They are often deemed unpredictable without complex measurement of the wave field and computationally intensive calculation which is infeasible in most applications, consequently there a need for fast predictors. Here we collate, quality control, and analyse the largest dataset of single‐point field measurements from surface following wave buoys to search for predictors of rogue wave occurrence. We find that analysis of the sea state parameters in bulk yields no predictors, as the subset of seas containing rogue waves sits within the set of seas without. However, spectral bandwidth parameters of rogue seas display different probability distributions to normal seas, but these parameters are rarely provided in wave forecasts. When location is accounted for, trends can be identified in the occurrence of rogue waves as a function of the average seas state characteristics at that location. These trends follow a power law relationship with the characteristic sea state parameters: mean significant wave height and mean zero up‐crossing wave period. We find that frequency of occurrence of rogue waves and their generating mechanism is not spatially uniform, and each location is likely to have its own unique sensitivities which increase in the coastal seas. We conclude that forecastable predictors of rogue wave occurrence will need to be location specific and reflective of their generation mechanism. Therefore, given location and a sufficiently long historical record of sea state characteristics, the likelihood of occurrence can be obtained for mariners and offshore operators. Plain Language Summary Rogue waves are waves much larger than expected for the surrounding sea state and their size and unexpected nature can pose a danger to ships and offshore structures. They are often thought to be unpredictable without complex computational calculation. Here we try to find the relationship between rogue wave occurrence and the characteristics of the sea state they occur in to circumnavigate this and allow prediction. Here we find that when all the data is analysed in bulk only weak relationships can be seen; however, when the data is analysed spatially relationships can be found between wave height and wave period and rogue wave occurrence. We find that the number of rogue waves and their cause differs spatially and note that each location is likely to have its own unique sensitivities which increase in the coastal seas. We conclude that forecastable predictors of rogue wave occurrence will need to be location specific, reflecting their cause. Therefore, given location and a sufficiently long historical record of sea state characteristics, the likelihood of occurrence can be obtained for mariners and offshore operators.

Item Type: Publication - Article
Digital Object Identifier (DOI): https://doi.org/10.1029/2018JC013958
ISSN: 21699275
Date made live: 06 Aug 2018 08:45 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/520662

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