Extreme Wave Analysis in Campos Basin (Rio de Janeiro - Brazil) Associated With Extra-Tropical Cyclones and Anticyclones

2012 ◽  
Author(s):  
Ricardo M. Campos ◽  
Carlos Eduardo Parente ◽  
Ricardo de Camargo
Keyword(s):  
Rio De Janeiro ◽  
Ocean Waves ◽  
Extreme Wave ◽  
Considerable Uncertainty ◽  
Campos Basin ◽  
Distribution Tail ◽  
Directional Wave ◽  
Tropical Weather ◽  
Tail Of Distribution ◽  
Buoy Data

Campos Basin is a petroleum rich area located offshore of Rio de Janeiro, Brazil. The most energetic ocean waves that reach location are generated by extra-tropical weather systems. This article studies extreme waves generated by cyclones and anticyclones, using two approaches. The first is the statistical extreme analysis applying the Peaks Over Threshold technique. The second is an evaluation of metocean features of events selected by POT as the tail of distribution. The research used 42 months of directional wave buoy measurements from 1991 to 1995 and 20 years of WAVEWATCH III simulation from 1986 to 2005, forced by NCEP/NCAR reanalysis2 surface winds. From metocean evaluation, the authors conclude that the greatest swells hitting Campos Basin come from southwest direction, peak periods over 11 seconds, generated by cyclones, occurring mainly in winter and autumn. The extreme buoy data analysis of significant wave height resulted in return values for 50 and 100 year respectively 8.77 and 9.54 meters, but with considerable uncertainty due to the short duration of data collection. Despite the limitations of Wavewatch hindcast, the methodology was able to capture the characteristics of extreme events in terms of shape of the distribution tail.

SHIP OPERABILITY PREDICTED FROM LONG TERM DIRECTIONAL WAVE RECORDS

2021 ◽  
Vol 153 (A2) ◽  
Author(s):  
D A Wing ◽  
M C Johnson
Keyword(s):  
Ocean Waves ◽  
Computational Effort ◽  
Data Sets ◽  
Wave Data ◽  
Directional Wave ◽  
Performance Results ◽  
Buoy Data ◽  
Sea Area ◽  
Ship Performance

Ship operability assessments have traditionally been made using wind and wave data derived from wave atlases, however there are several drawbacks, including the fact that they are usually based on observation rather than measurement, and that spreading or directional effects are lost – such as the separation of sea and swell directions. An alternative approach is demonstrated here, instead of the data summarised in the wave atlas scatter diagram, long term hourly historical wave buoy data may be used. Detailed data sets, including directional wave spectra, are available for a number of specific locations. Direct use of many years’ hourly wave data involves significant computational effort, but results may be achieved within a reasonable time. The technique is demonstrated with the examples of four naval ships and two sites. Analysis considered two main themes, the differences in the ship performance calculated when (a) using wave buoy data rather than wave atlas data for the same sea area and (b) using the most complex available model of the ocean waves compared with the simplified wave descriptions in common use. For (a) the wave buoy data both looked rather different than the wave buoy data for the same nominal area, and produced rather different ship performance results. For (b) it was shown that there were also significant differences between the operability calculated for the four different ships at one of the sites. The implications for operability assessment in the ship procurement process are briefly discussed.

scholarly journals Assessment of reliability of extreme wave height prediction models

2017 ◽  
Vol 17 (3) ◽  
pp. 409-421 ◽  
Author(s):  
Satish Samayam ◽  
Valentina Laface ◽  
Sannasiraj Sannasi Annamalaisamy ◽  
Felice Arena ◽  
Sundar Vallam ◽  
...  
Keyword(s):  
North America ◽  
Mediterranean Sea ◽  
Wave Height ◽  
Prediction Models ◽  
North Pacific Ocean ◽  
Coastal Hazards ◽  
Extreme Wave ◽  
Indian Water ◽  
Wave Hindcast ◽  
Buoy Data

Abstract. Extreme waves influence coastal engineering activities and have an immense geophysical implication. Therefore, their study, observation and extreme wave prediction are decisive for planning of mitigation measures against natural coastal hazards, ship routing, design of coastal and offshore structures. In this study, the estimates of design wave heights associated with return period of 30 and 100 years are dealt with in detail. The design wave height is estimated based on four different models to obtain a general and reliable model. Different locations are considered to perform the analysis: four sites in Indian waters (two each in Bay of Bengal and the Arabian Sea), one in the Mediterranean Sea and two in North America (one each in North Pacific Ocean and the Gulf of Maine). For the Indian water domain, European Centre for Medium-Range Weather Forecasts (ECMWF) global atmospheric reanalysis ERA-Interim wave hindcast data covering a period of 36 years have been utilized for this purpose. For the locations in Mediterranean Sea and North America, both ERA-Interim wave hindcast and buoy data are considered. The reasons for the variation in return value estimates of the ERA-Interim data and the buoy data using different estimation models are assessed in detail.

Simulation of Hurricane Seas in a Multidirectional Wave Basin

1991 ◽  
Vol 113 (3) ◽  
pp. 219-227 ◽  
Author(s):  
A. Cornett ◽  
M. D. Miles
Keyword(s):  
Ocean Waves ◽  
Entropy Method ◽  
Wave Spectra ◽  
Single Wave ◽  
Wave Condition ◽  
Wave Basin ◽  
Wide Range ◽  
Directional Wave ◽  
Wave Conditions ◽  
Multidirectional Wave

This paper describes the generation and verification of four realistic sea states in a multidirectional wave basin, each representing a different storm wave condition in the Gulf of Mexico. In all cases, the degree of wave spreading and the mean direction of wave propagation are strongly dependent on frequency. Two of these sea states represent generic design wave conditions typical of hurricanes and winter storms and are defined by JONSWAP wave spectra and parametric spreading functions. Two additional sea states, representing the specific wave activity during hurricanes Betsy and Carmen, are defined by tabulated hindcast estimates of the directional wave energy spectrum. The Maximum Entropy Method (MEM) of directional wave analysis paired with a single-wave probe/ bi-directional current meter sensor is found to be the most satisfactory method to measure multidirectional seas in a wave basin over a wide range of wave conditions. The accuracy of the wave generation and analysis process is verified using residual directional spectra and numerically synthesized signals to supplement those measured in the basin. Reasons for discrepancy between the measured and target directional wave spectra are explored. By attempting to reproduce such challenging sea states, much has been learned about the limitations of simulating real ocean waves in a multidirectional wave basin, and about techniques which can be used to minimize the associated distortions to the directional spectrum.

Estimating Ricochet Hazard Zones at Sea

2018 ◽  
Vol 15 (4) ◽  
pp. 399-413
Author(s):  
Ramzi Mirshak ◽  
Talia Beech
Keyword(s):  
Simple Model ◽  
Ocean Waves ◽  
Considerable Effect ◽  
Controlled Experiments ◽  
Risk Area ◽  
Wave Fields ◽  
Considerable Uncertainty ◽  
Hazard Zone ◽  
The Right ◽  
Two Degree Of Freedom

Naval operators commonly report that when projectiles impact the ocean surface, they ricochet mainly to the right but that some rounds ricochet in wildly unpredictable directions. This observation, which leads to considerable uncertainty with regard to the resulting hazard zone for projectiles fired at sea, seems contradictory to observations from controlled experiments where projectiles with similar incident angles tend to ricochet in a more predictable manner. In this paper, we postulate that the likely cause of the discrepancy is ocean waves. Past work examining the effect of waves on ricochet is extended to model the risk area related to projectile ricochet at sea. Ricochet results from controlled experiments are incorporated into a simple model that combines a two-degree-of-freedom ballistic model and a series of analytically derived wave fields with different amplitudes and directions of travel. For the purposes of demonstration in this paper, data for different .50 calibre projectiles are used to populate the model. The results support the notion that waves have a considerable effect on ricochet hazard zones.

K-Ar AND Rb-Sr DATING OF NANOMETER-SIZED SMECTITE-RICH MIXED LAYERS FROM BENTONITE BEDS OF THE CAMPOS BASIN (RIO DE JANEIRO STATE, BRAZIL)

2020 ◽  
Vol 68 (5) ◽  
pp. 446-464
Author(s):  
Norbert Clauer ◽  
Jan Środoń ◽  
Amélie Aubert ◽  
I. Tonguç Uysal ◽  
Theofilos Toulkeridis
Keyword(s):  
Rio De Janeiro ◽  
Campos Basin ◽  
Mixed Layers ◽  
Janeiro State

scholarly journals Validation of Sentinel-3A/3B and Jason-3 Altimeter Wind Speeds and Significant Wave Heights Using Buoy and ASCAT Data

2020 ◽  
Vol 12 (13) ◽  
pp. 2079 ◽  
Author(s):  
Jungang Yang ◽  
Jie Zhang ◽  
Yongjun Jia ◽  
Chenqing Fan ◽  
Wei Cui
Keyword(s):  
Ocean Waves ◽  
Global Ocean ◽  
Spatial And Temporal Scales ◽  
Significant Wave ◽  
Wind Speeds ◽  
Wave Heights ◽  
Buoy Data ◽  
Over Time ◽  
Moored Buoy ◽  
Better Than

This study validated wind speed (WS) and significant wave height (SWH) retrievals from the Sentinel-3A/3B and Jason-3 altimeters for the period of data beginning 31 October 2019 (to 18 September 2019 for Jason-3) using moored buoy data and satellite Meteorological Operational Satellite Program (MetOp-A/B) Advanced Scatterometer (ASCAT) data. The spatial and temporal scales of the collocated data were 25 km and 30 min, respectively. The statistical metrics of root mean square error (RMSE), bias, correlation coefficient (R), and scatter index (SI) were used to validate the WS and SWH accuracy. Validation of WS against moored buoy data indicated errors of 1.19 m/s, 1.13 m/s and 1.29 m/s for Sentinel-3A, Sentinel-3B and Jason-3, respectively. The accuracy of Sentinel-3A/3B WS is better than that of Jason-3. All three altimeters underestimated WS slightly in comparison with the buoy data. Errors in WS at different speeds or SWHs increased slightly as WS or SWH increased. Over time, the accuracy of the Jason-3 altimeter-derived WS improved, whereas that of Sentinel-3A showed no temporal dependence. The WSs of the three altimeters were compared with ASCAT wind data for validation purposes over the global ocean without in situ measurements. On average, the WSs of the three altimeters were lower in comparison with the ASCAT data. The accuracy of the three altimeters was found to be consistent and stable at low/medium speeds but it decreased when the WS exceeded 15 m/s. Validations of SWH against buoy wave data indicated that the accuracy of Jason-3 SWH was better than that of Sentinel-3A/3B. However, the accuracy of all three altimeters decreased when the SWH exceeded 4 m. The accuracy of Sentinel-3A and Jason-3 SWH was temporally stable, whereas that of Sentinel-3B SWH improved over time. Analyses of SWH accuracy as a function of wave period showed that the Jason-3 altimeter was better than the Sentinel-3A/3B altimeters for long-period ocean waves. Generally, the accuracy of WS and SWH data derived by the Sentinel-3A/3B and Jason-3 altimeters satisfies their mission requirements. Overall, the accuracy of WS (SWH) derived by Sentinel-3A/3B (Jason-3) is better than that retrieved by Jason-3 (Sentinel-3A/3B).

Spirodesma magdae nov. gen. nov. sp. (Nematoda: Desmodoridae) from the Brazilian deep sea (Campos Basin, Rio de Janeiro, Brazil)

Zootaxa ◽  
2009 ◽  
Vol 2096 (1) ◽  
pp. 109-118 ◽  
Author(s):  
MARIANA DA FONSECA CAVALCANTI ◽  
MARIA CRISTINA DA SILVA ◽  
VERÔNICA DA FONSÊCA-GENEVOIS
Keyword(s):  
New Species ◽  
Deep Sea ◽  
Rio De Janeiro ◽  
New Genus ◽  
Buccal Cavity ◽  
Morphological Features ◽  
New Genus And Species ◽  
Unique Form ◽  
Campos Basin ◽  
Deep Sea Sediments

A new genus and species of Desmodoridae was found in deep-sea sediments of the Campos Basin. Although the cuticle annulation of the new species is similar to members of Desmodorinae, many morphological features are strong enough to classify it within the Spiriniinae. Spirodesma magdae nov. gen. nov. sp. is characterized mainly by the presence of a unique form of unispired amphids, with circular amphideal fovea, and a buccal cavity with three equal teeth, one dorsal and two ventrosublateral.

scholarly journals Evolution of a Random Directional Wave and Freak Wave Occurrence

2009 ◽  
Vol 39 (3) ◽  
pp. 621-639 ◽  
Author(s):  
Takuji Waseda ◽  
Takeshi Kinoshita ◽  
Hitoshi Tamura
Keyword(s):  
Wave Height ◽  
Wave Interaction ◽  
Northwest Pacific ◽  
Frequency Bandwidth ◽  
Extreme Wave ◽  
Spectral Parameters ◽  
Freak Wave ◽  
Resonant Wave ◽  
Directional Wave ◽  
Wind Sea

Abstract The evolution of a random directional wave in deep water was studied in a laboratory wave tank (50 m long, 10 m wide, 5 m deep) utilizing a directional wave generator. A number of experiments were conducted, changing the various spectral parameters (wave steepness 0.05 < ɛ < 0.11, with directional spreading up to 36° and frequency bandwidth 0.2 < δk/k < 0.6). The wave evolution was studied by an array of wave wires distributed down the tank. As the spectral parameters were altered, the wave height statistics change. Without any wave directionality, the occurrence of waves exceeding twice the significant wave height (the freak wave) increases as the frequency bandwidth narrows and steepness increases, due to quasi-resonant wave–wave interaction. However, the probability of an extreme wave rapidly reduces as the directional bandwidth broadens. The effective Benjamin–Feir index (BFIeff) is introduced, extending the BFI (the relative magnitude of nonlinearity and dispersion) to incorporate the effect of directionality, and successfully parameterizes the observed occurrence of freak waves in the tank. Analysis of the high-resolution hindcast wave field of the northwest Pacific reveals that such a directionally confined wind sea with high extreme wave probability is rare and corresponds mostly to a swell–wind sea mixed condition. Therefore, extreme wave occurrence in the sea as a result of quasi-resonant wave–wave interaction is a rare event that occurs only when the wind sea directionality is extremely narrow.

Four new species of Sabatieria Rouville, 1903 (Nematoda, Comesomatidae) from the Continental Slope of Atlantic Southeast

Zootaxa ◽  
2007 ◽  
Vol 1402 (1) ◽  
pp. 39 ◽  
Author(s):  
ALESSANDRA PRATES BOTELHO ◽  
MARIA CRISTINA DA SILVA ◽  
ANDRÉ MORGADO ESTEVES ◽  
VERÔNICA FONSÊCA-GENEVOIS
Keyword(s):  
New Species ◽  
Continental Slope ◽  
Rio De Janeiro ◽  
Distal Part ◽  
Maximum Diameter ◽  
Campos Basin ◽  
Tail Shape ◽  
Abundant Genus

Sabatieria is the most abundant genus along the Campos Basin, Rio de Janeiro (Brazil). Four new species of Sabatieria (Nematoda-Comesomatidae) from the Continental Slope of Atlantic Southeast are described. Sabatieria spiculata sp.nov. is characterized by the size of spicule and the presence of dorsal tooth ; S. paraspiculata sp. nov. by tail shape and the maximum diameter; S. bitumen sp. nov. by spicule shape with an arrow-like distal part and the S. subrotundicauda sp.nov. by a round tail and reflected ovary.

Spirinia lara sp. n. and Spirinia sophia sp. n. (Nematoda, Desmodoridae) from the Brazilian continental margin (Campos Basin, Rio de Janeiro)

Zootaxa ◽  
2009 ◽  
Vol 2081 (1) ◽  
pp. 31-45 ◽  
Author(s):  
MARIA CRISTINA DA SILVA ◽  
FRANCISCO JOSÉ VICTOR DE CASTRO ◽  
MARIANA DA FONSECA CAVALCANTI ◽  
VERÔNICA DA FONSÊCA-GENEVOIS
Keyword(s):  
New Species ◽  
Continental Margin ◽  
Deep Sea ◽  
Rio De Janeiro ◽  
The Body ◽  
Irregular Distribution ◽  
Gland Cells ◽  
Campos Basin ◽  
Two New Species ◽  
Deep Sea Sediments

In deep-sea sediments from Campos Basin two new species of Spirinia were found. Spirinia lara sp. n. is mainly characterized by the presence of paired somatic papillae linked to gland cells and distributed all over the body while Spirinia sophia sp. n. possesses an irregular distribution of these glandular somatic papillae.

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