Are There Different Kinds of Rogue Waves?

Author(s):  
Paul C. Liu ◽  
Keith R. MacHutchon

There is clearly no immediate answer to the question posted by the title of this paper. Inasmuch as that there are not much definitively known about rogue waves and that there is still no universally accepted definition for rogue waves in the ocean, we think there might just be even more than one kind of rogue waves to contend with. While the conventional approach has generally designated waves with Hmax∕Hs greater than 2.2 as possible rogue waves, based on Rayleigh distribution considerations, there is conspicuously no provision as to how high the ratio of Hmax∕Hs can be and thus not known how high can a rogue wave be. In our analysis of wave measurements made from a gas-drilling platform in South Indian Ocean, offshore from Mossel Bay, South Africa, we found a number of cases that indicated Hmax∕Hs could be valued in the range between 4 and 10. If this were to be the case, then these records could be considered to be “uncommon” rogue waves, whereas a record of Hmax∕Hs in the range between 2 and 4 could be considered to comprise “typical” rogue waves. On the other hand, the spikes in the Hmax data could have been caused by equipment malfunction or some other phenomenon. Clearly, the question of whether or not there are different kinds of rogue waves cannot be readily answered by theoretical considerations alone and there is a crucial need for long-term wave time-series measurements for studying rogue waves.

Author(s):  
Paul C. Liu ◽  
Keith R. MacHutchon

Inasmuch as there is as yet still no universally accepted definition for rogue waves in the ocean, we think there might just be more than one kind of rogue waves to contend with. While the conventional approach has generally designated waves with Hmax/Hs greater than 2.2 as possible rogue waves, based on Rayleigh distribution considerations, there is conspicuously no provision as to how high the ratio of Hmax/Hs can be. In our analysis of wave measurements made from a gas-drilling platform in South Indian Ocean, offshore from Mossel Bay, South Africa, we found a number of cases that indicated Hmax/Hs could be valued in the range between 4 and 10. If this were to be the case these records could be considered to be “uncommon” rogue waves, whereas a record of Hmax/Hs in the range between 2 and 4 could be considered to comprise “typical” rogue waves. On the other hand the spikes in the Hmax data could have been caused by equipment malfunction or some other phenomenon. Clearly the question of whether or not there are different kinds of rogue waves can not be readily answered by theoretical considerations alone and there is a crucial need for long-term wave time series measurements for studying rogue waves.


2021 ◽  
Author(s):  
Marion Peral ◽  
Thibaut Caley ◽  
Bruno Malaizé ◽  
Erin McClymont ◽  
Thomas Extier ◽  
...  

<p>The Mid-Pleistocene transition (MPT) took place between 1,200 Ma and 800 ka (still debated). During this transition, the Earth’s orbitally paced ice age cycles intensified, lengthened from ∼40 000 (∼40 ky) to ∼100 ky, and became distinctly asymmetrical while Earth’s orbital variations remained unchanged. Although orbital variations constitute the first order forcing on glacial-interglacial oscillations of the late Quaternary, they cannot explain alone the shifts in climatic periodicity and amplitude observed during the MPT. In order to explain the MPT, long-term evolution of internal mechanisms and feedbacks have been called upon, in relation with the global cooling trend initiated during the Cenozoic, the expansion of Antarctic and Greenland Ice Sheet and/or the long-term decline in greenhouse gases (particularly CO2). A key point is therefore to accurately reconstruction of oceanic temperatures to decipher the processes driving climate variations.</p><p>In the present work, we studied the marine sediment core MD96-2048 taken from south Indian Ocean (26*10’482’’ S, 34*01’148’’ E) in the region of the Agulhas current. We compared 5 paleothermometers: alkenone, TEX86, foraminiferal- transfer function, Mg/Ca and clumped isotope. Among these approaches, carbonate clumped-isotope thermometry (∆<sub>47</sub>) only depends on crystallization temperature, and the ∆<sub>47</sub> relationship with planktonic foraminifer calcification temperature is well defined. Since Mg/Ca is not only controlled by temperature but is also affected by salinity and pH. The classical d<sup>18</sup>O in planktic is dependent on SST and d<sup>18</sup>Osw, which is regionally correlated with the salinity in the present-day ocean. Assuming that the present-day d<sup>18</sup>O<sub>sw</sub>-salinity relation was the same during the MPT, we are able to separate changes in d<sup>18</sup>O<sub>sw</sub> from temperature effects and reconstruct past salinity. Combining d<sup>18</sup>O, Mg/Ca and ∆<sub>47</sub> on planktonic foraminifera allow in theory to reconstruct SST, SSS and pH.</p><p>Here, we measured d<sup>18</sup>O, Mg/Ca and ∆<sub>47</sub> on the shallow-dwelling planktonic species Globigerinioides ruber ss. at the maximal of glacial and interglacial periods over the last 1.2 Ma. Our set of data makes it possible to estimate the long-term evolution of SST, salinity and pH (and thus have an insight into the atmospheric CO<sub>2</sub> concentration) across the MPT. Frist, strong differences are observed between the 5 derived-SST: the alkenone and TEX86 recorded the higher temperatures than the other SST proxies. Alkenone derived-SST do not show glacial-interglacial variations within the MPT. The Mg/Ca and transfer function derived-SST show a good agreement each other, while the clumped-isotope derived-SST are systematically colder than the other derived-SST. Then, our ∆<sub>47</sub>-SST, salinity and pH results clearly show that amplitude of glacial-interglacial variations was insignificant between 1.2 and 0.8 Ma (within the MPT) and increased after the MPT. Finally, we also discussed the potential to use this unique combination of proxies to reconstruct changes of atmospheric CO<sub>2</sub> concentration.</p>


1999 ◽  
Vol 42 (2) ◽  
Author(s):  
Y. Nogi ◽  
K. Kaminuma

Vector measurements of the geomagnetic field have been made in the South Indian Ocean since 1988 when a Shipboard Three Component Magnetometer (STCM) was installed on board the icebreaker Shirase by the 30th Japanese Antarctic Research Expedition (JARE-30). Twelve constants related to the ship's induced and permanent magnetic field were determined by the data obtained from the JARE-30 to the JARE-35. The constants related to the ship's magnetic susceptibility distribution are almost stable throughout the cruise and mostly depend on the ship's shape. On the other hand, the constants related to the ship's permanent magnetization are variable. However, absolute values of total intensity geomagnetic field calculated from vector geomagnetic field is possible to use, if the constraints from total intensity geomagnetic field measured by the proton magnetometer and/or satellite derived magnetic anomalies are applied.


Author(s):  
Alexey Slunyaev ◽  
Anna Kokorina

The asymmetry between the troughs from the rear and front sides of rogue waves is the particular object of the present study. In our previous simulations of unidirectional waves the typical picture of a rogue waves possesses the trend that most of the rogue waves where characterized by deeper rear troughs. In the present work we broaden the discussion of the rogue wave front-to-crest asymmetry to the directional case. The direct numerical simulation of primitive water equations is an affordable alternative to the in-situ or laboratory measurements, in particularly when the interest is focused on the long-term evolution or on the detailed consideration of the water wave movement in space and time. In this work we simulate irregular surface waves in the hydrodynamic equations using the High-Order Spectral Method, and focus on the so-called rogue waves.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/plseXdjpE6c


Author(s):  
Джордж Парарас-Караяннис

Пересмотренные официальные записи Следственного суда ВМС США содержат выводы о том, что разрушение бронированного крейсера USS Memphis 29 августа 1916 года на якоре у гавани Санто-Доминго (Сьюдад-Трухильо) Доминиканской Республики, остров Эспаньола, вероятно, было вызвано «тропическим волнением» «сейсмической бурей» или «цунами». Тем не менее, современный анализ этой морской катастрофы свидетельствует о том, что гибель корабля произошла не по какой-либо из этих причин, а из-за волн-убийц метеоцунами, вызванных быстрым, значительным и прогрессирующим падением атмосферного давления, которое началось в районе около 22 августа и было связано с проходящим ураганом, который в его самой близкой точке был около 250 морских миль на юг. Кроме того, штормовые волны от этого урагана двигались в направлении Санто-Доминго, преломляясь в резонансе у берега, и усиливались и трансформировались низким барометрическим давлением, мелким континентальным шельфом и местными особенностями побережья и батиметрией залива. Настоящий анализ основан на тщательном изучении судового журнала и наблюдений за событиями со стороны экипажа и людей на берегу. Учитывая ограниченные метеорологические данные того периода времени, в настоящем анализе использовался эмпирический подход для грубой оценки функции распределения Рэлея, верхнего предела изменчивости высоты штормовой волны вдали от наиболее интенсивных потоков ветра, а также максимального периода, длины волны и амплитуды генерируемых штормовых волн в глубине . Основываясь на теориях кноидальных волн и волн Эйри, период и скорость наиболее значительных экстремальных внутренних волн имели метеорологическое происхождение, которое было преобразовано в мелкой воде в результате резонансного и наложенного прихода двух других волн, которые создали трехступенчатое плато, на переднем фронте огромная одиночная волна-убийца метеоцунами высотой около 70 футов, с тремя четкими ступенями, двумя плато на передней поверхности и предшествующей впадиной длиной около 300 футов. Основываясь на этом анализе, настоящее исследование пришло к выводу, что именно эта значительная волна метеоцунами / волна-убийца в сочетании с одновременно прибывающими штормовыми волнами охватила Мемфис USS в 16 ч. 40 м. 29 августа 1916 года, разорвав цепи якорей и разрушая его на скалах Санто-Доминго. Official revised records of a U.S. Navy Court of Inquiry concluded that the 29 August 1916 destruction of the armored cruiser USS Memphis anchored off Santo Domingo (Ciudad Trujillo) harbor of the Dominican Republic, Island of Hispaniola, was probably caused by a “tropical disturbance”, a “seismic storm”, or a “tsunami”. However, the present analysis of this naval disaster documents that the loss of the ship was not due to any of these causes, but to rogue waves of a meteotsunami generated from a rapid, significant and progressive drop in atmospheric pressure which begun in the area around August 22 and was associated with a passing hurricane which at its closest point was about 250 nautical miles to the south. Also, storm waves from this hurricane moved towards Santo Domingo refracting in resonance near shore and were further amplified and transformed by the low barometric pressure, the shallow continental shelf and the local coastal features and bathymetry of the bay. The present analysis is based on careful examination of the ship’s log, and on observations of events by the crew and people on the shore. Given the limited meteorological data of that time period, the present analysis used an empirical approach to roughly evaluate the Rayleigh distribution function, the upper limit of storm wave height variability away from the most intense wind fetches, as well as the maximum period, wavelength and deep-water heights of generated storm waves. Based on Airy and cnoidal wave theories, the deep water period and celerity of the most significant extreme wave was of meteorological origin which was transformed in shallower water by the resonant and superimposed arrival of two other waves which created a three step plateau on the face of a huge single rogue wave of the meteotsunami, estimated to be about 70 feet in height, with three distinct steps, two plateaus on its forward face, and a preceding trough estimated to be 300 ft. long. Based on this analysis, the present study concluded that it was this significant meteotsunami/rogue wave, in combination with concurrently arriving storm swells, that engulfed the USS Memphis at 1640 hour in the afternoon of 29 August 1916 - breaking the chains of its anchors and wrecking it on the rocks of Santo Domingo.


2014 ◽  
Vol 14 (9) ◽  
pp. 2521-2527 ◽  
Author(s):  
Y. Wang ◽  
A.-F. Tao ◽  
J.-H. Zheng ◽  
D.-J. Doong ◽  
J. Fan ◽  
...  

Abstract. Due to the potential disasters induced by rogue waves, research in this field has increased rapidly in the last 2 decades. However, there are still a lot of open questions left, including some classic ones, such as whether the rogues waves are just rare events or not. One of the key reasons is that not enough of the observed rogue waves have been investigated. China has a wide sea area, but none of the research has addressed the observed rogue waves. In the present study, 1 year of observed wave data from Jiangsu coastal area, China, are analyzed. It is found that rogue waves are present, although the wave heights are not very large; furthermore, the probability of their occurrence is similar to the Rayleigh distribution prediction, due to the local silty coastal topography. The characteristics of rouge waves are investigated and the results indicate that a new type of rogue wave may exist.


2004 ◽  
Vol 23 (1) ◽  
pp. 15-38 ◽  
Author(s):  
Michael A. Ayress ◽  
Patrick De Deckker ◽  
Graham P. Coles

Abstract. From an examination of 34 grab and dredge samples ranging from 110 m to 3584 m water depth, collected during Eltanin cruise 47 across the Kerguelen Plateau, 26 shallow-water and 35 deep-sea benthonic ostracod species have been identified. Systematic notes and illustrations of the common and some of the rare species are presented. Two new species are described: Philoneptunus cassidyi n. sp. and Taracythere abyssora n. sp. Comparisons made with the Atlantic and SW Pacific Oceans and circum-Antarctic regions indicate that the fauna comprises dominantly cosmopolitan deep-sea species while most of the other species have close affinities with the SW Pacific. In the Kerguelen material, seven distinct depth assemblages appear to correspond well with differing watermasses and there is evidence that the relatively shallow position of Antarctic Intermediate Water permits elevation of the upper depth limits of some deep-sea species. Some species have developed ornament of fine reticulation, features not previously seen in those species outside the Kerguelen region.


2020 ◽  
Author(s):  
Ina Teutsch ◽  
Ralf Weisse ◽  
Jens Moeller ◽  
Oliver Krueger

Abstract. A new wave dataset from the southern North Sea covering the period 2011–2016 and composed of wave buoy and radar measurements sampling the sea surface height at frequencies between 1.28–4 Hz was quality controlled and scanned for the presence of rogue waves. Here rogue waves refer to waves whose height exceeds twice the significant wave height. Rogue wave frequencies were analysed, compared to Rayleigh and Forristall distributions, and spatial, seasonal and long-term variability was assessed. Rogue wave frequency appeared to be relatively constant over the course of the year and uncorrelated among the different measurement sites. While data from buoys basically correspond with expectations from the Forristall distribution, radar measurement showed some deviations in the upper tail pointing towards higher rogue wave frequencies. Number of data available in the upper tail is, however, still limited to allow a robust assessment. Some indications were found that the distribution of waves in samples with and without rogue waves were different in a statistical sense. However, differences were small and deemed not to be relevant as attempts to use them as a criterion for rogue wave detection were not successful in Monte Carlo experiments based on the available data.


2018 ◽  
Vol 32 (10) ◽  
pp. 1850086 ◽  
Author(s):  
Xiao-Yue Jia ◽  
Bo Tian ◽  
Zhong Du ◽  
Yan Sun ◽  
Lei Liu

Under investigation in this paper is the variable-coefficient Kadomtsev–Petviashvili equation, which describes the long waves with small amplitude and slow dependence on the transverse coordinate in a single-layer shallow fluid. Employing the bilinear form and symbolic computation, we obtain the lump, mixed lump-stripe soliton and mixed rogue wave-stripe soliton solutions. Discussions indicate that the variable coefficients are related to both the lump soliton’s velocity and amplitude. Mixed lump-stripe soliton solutions display two different properties, fusion and fission. Mixed rogue wave-stripe soliton solutions show that a rogue wave arises from one of the stripe solitons and disappears into the other. When the time approaches 0, rogue wave’s energy reaches the maximum. Interactions between a lump soliton and one-stripe soliton, and between a rogue wave and a pair of stripe solitons, are shown graphically.


2020 ◽  
Vol 20 (10) ◽  
pp. 2665-2680
Author(s):  
Ina Teutsch ◽  
Ralf Weisse ◽  
Jens Moeller ◽  
Oliver Krueger

Abstract. A new wave data set from the southern North Sea covering the period 2011–2016 and composed of wave buoy and radar measurements sampling the sea surface height at frequencies between 1.28 and 4 Hz was quality controlled and scanned for the presence of rogue waves. Here, rogue waves refer to waves whose height exceeds twice the significant wave height. Rogue wave frequencies were analyzed and compared to Rayleigh and Forristall distributions, and spatial, seasonal, and long-term variability was assessed. Rogue wave frequency appeared to be relatively constant over the course of the year and uncorrelated among the different measurement sites. While data from buoys basically correspond with expectations from the Forristall distribution, radar measurement showed some deviations in the upper tail pointing towards higher rogue wave frequencies. The amount of data available in the upper tail is, however, still too limited to allow a robust assessment. Some indications were found that the distribution of waves in samples with and without rogue waves was different in a statistical sense. However, differences were small and deemed not to be relevant as attempts to use them as a criterion for rogue wave detection were not successful in Monte Carlo experiments based on the available data.


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