scholarly journals EXTREME WAVE CONDITIONS IN BRITISH AND ADJACENT WATERS

1972 ◽  
Vol 1 (13) ◽  
pp. 6 ◽  
Author(s):  
Laurence Draper
Keyword(s):  
Wave Height ◽  
Offshore Structures ◽  
Wave Period ◽  
The Other ◽  
Wind Data ◽  
Extreme Wave ◽  
Wave Measurements ◽  
Extreme Wind ◽  
Wave Conditions

Information on extreme wave conditions is needed in the design of offshore structures. This paper present the results of calculations of the parameters in the 50-year storm; the work has been based on extreme wind data and on instrumental wave measurements. The results are complementary, and are combined in two maps, one of extreme wave height and the other of the corresponding wave period.

scholarly journals Pemanfaatan Data Angin Untuk Karakteristik Gelombang Laut Di Perairan Natuna Berdasarkan Data Angin tahun 2009 - 2018

2019 ◽  
Vol 8 (2) ◽  
pp. 55
Author(s):  
Ary Afriady ◽  
Tasdik Mustika Alam ◽  
Mochamad Furqon Mustika Azis Ismail
Keyword(s):  
Wave Height ◽  
Wave Period ◽  
Wind Data ◽  
Wave Direction ◽  
The West ◽  
Maximum Wave Height ◽  
Transition Season ◽  
Forecasting Analysis ◽  
Environmental Prediction ◽  
Wave Forecasting

Analisis data angin dilakukan untuk meramalkan dan menentukan karakteristik gelombang laut di perairan Pulau Natuna. Data angin yang digunakan dalam penelitian ini berasal dari National Centers for Environmental Prediction (NCEP) selama 10 tahun dari tahun 2009 sampai dengan tahun 2018. Metoda yang digunakan untuk estimasi tinggi, periode dan arah gelombang laut yang dibangkitkan oleh angin adalah metode Svedrup, Munk dan Bretschneider (SMB). Hasil perhitungan peramalan karakteristik gelombang diperoleh bahwa pembentukan gelombang didominasi oleh arah yang berasal dari timur laut dan terjadi pada musim barat dan musim peralihan 1. Adapun pada musim timur dan peralihan, arah dominan gelombang masing-masing berasal dari selatan dan barat daya. Tinggi gelombang maksimum 1,0-1,4 m sering terjadi pada musim musim timur, adapun tinggi gelombang minimum 0,2-0,6 m dominan terjadi pada musim musim peralihan. Periode gelombang dominan ditemukan pada kisaran 7-9 detik yang terjadi pada tiap musim.  The analysis of wind data has been done to forecast and determine the characteristic of the ocean wave in Natuna Island waters. The wind data in this study came from the National Centers for Environmental Prediction (NCEP) for a period of 10 years from 2009 to 2018. The method to estimate wave height, wave period, and wave direction generated by wind is Sverdrup, Munk dan Bretschneider (SMB) system. The results of wave forecasting analysis show that the formation of the wave is mainly originated from the northeast which occurs during the west and first transition season. As for the east and second transition season, the origin of wave formation coming from the south and southwest, respectively. The maximum wave height of 1.0-1.4 m frequently occurs during the east monsoon, while the minimum wave height. The dominant wave period is found in the range of 7-9 seconds, which occurs in every season. 

The Equivalent Power Storm Model for Long-Term Predictions of Extreme Wave Events

2009 ◽  
Author(s):  
Francesco Fedele ◽  
Felice Arena
Keyword(s):  
Wave Height ◽  
Return Period ◽  
Shape Parameter ◽  
Extreme Wave ◽  
Maximum Wave Height ◽  
Wave Measurements ◽  
Sea Storm ◽  
Storm Model ◽  
Good Agreement

We present the Equivalent Power Storm (EPS) model as a generalization of the Equivalent Triangular Storm (ETS) model of Boccotti for the long-term statistics of extreme wave events. In the EPS model, each actual storm is modeled in time t by a power law ∼|t−t0|λ, where λ is a shape parameter and t0 is the time when the storm peak occurs. We then derive the general expression of the return period R(Hs > h) of a sea storm in which the maximum significant wave height Hs exceeds a fixed threshold h as function of λ. Further, given the largest wave height Hmax, we identify the most probable storm in which the largest wave occurs and derive an explicit expression for the return period R(Hmax >H) of a storm in which the maximum wave height exceeds a given threshold H. Finally, we analyze wave measurements retrieved from two of the NOAA-NODC buoys in the Atlantic and Pacific oceans and find that the EPS predictions are in good agreement with those from the ETS model.

Systematically Varied Rogue Wave Sequences for the Experimental Investigation of Extreme Structure Behavior

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Günther F. Clauss ◽  
Christian E. Schmittner ◽  
Janou Hennig
Keyword(s):  
Wave Height ◽  
Rogue Wave ◽  
Wave Train ◽  
Weather Conditions ◽  
Offshore Structures ◽  
Severe Weather ◽  
Wave Profile ◽  
Bending Moments ◽  
Extreme Wave ◽  
Improved Design

For an improved design of ships and offshore structures with regard to their behavior under severe weather conditions, wave height and steepness as well as the shape of the wave profile have to be considered. In this paper, the extreme new year wave as documented in numerous publications is varied with respect to wave height and period. These varied wave sequences are realized and measured in a model tank and applied to the investigation of motions and bending moments of a floating production storage and offloading ship. The results are compared to the responses in the original wave train. An investigation of the riskiness of extreme wave sequences in comparison with existing rules concludes this paper.

scholarly journals Assessment of reliability of extreme wave height prediction models

2016 ◽  
Author(s):  
Satish Samayam ◽  
Valentina Laface ◽  
Sannasiraj Sannasi Annamalaisamy ◽  
Felice Arena ◽  
Sundar Vallam ◽  
...  
Keyword(s):  
North America ◽  
Mediterranean Sea ◽  
Wave Height ◽  
Prediction Models ◽  
Offshore Structures ◽  
Coastal Hazards ◽  
Mitigation Measures ◽  
Extreme Wave ◽  
Indian Water ◽  
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 for 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, one in Mediterranean Sea and two in North America. For the Indian water domain European Centre for Medium-Range Weather Forecasts (ECMWF) global atmospheric reanalysis ERA-interim wave hind cast 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 hind cast 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.

Forecasting Hawaiian Swell from January 2 to 5, 1947 1

1948 ◽  
Vol 29 (8) ◽  
pp. 395-400 ◽  
Author(s):  
Robert S. Arthur
Keyword(s):  
Travel Time ◽  
Group Velocity ◽  
Wave Height ◽  
Hawaiian Islands ◽  
Extreme Wave ◽  
Maximum Wave Height ◽  
Wave Characteristics ◽  
Wave Conditions ◽  
Forecasting Techniques

The adequacy of existing forecasting techniques is demonstrated for a situation involving extreme wave conditions on the northern shores of the Hawaiian Islands. Computations of wave characteristics as made from Sverdrup and Munk's revised relationships show that this unusually high swell could be forecast more than 24 hours in advance. Travel time is computed on the basis of the group velocity at the end of the decay distance. The situation affords a particularly good check on computed travel time since the time of maximum wave height is observed at both the Hawaiian and Palmyra Islands.

Comparative wave measurements at a wave energy site with a recently developed low-cost wave buoy (Spotter), ADCP and pressure loggers

2021 ◽  
Author(s):  
Orrin Lancaster ◽  
Remo Cossu ◽  
Sebastien Boulay ◽  
Scott Hunter ◽  
Tom E. Baldock
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Significant Wave Height ◽  
Low Cost ◽  
Wave Period ◽  
Wave Direction ◽  
Mean Values ◽  
Significant Wave ◽  
Wave Measurements ◽  
The Mean

AbstractWave measurements from a new, low-cost, real-time wave buoy (Spotter) are investigated in a comparative study as part of a site characterization study at a wave energy candidate site at King Island, Tasmania, Australia. Measurements from the Sofar Ocean Spotter buoy are compared with concurrent measurements from a Teledyne RD Instrument (RDI) 1200 kHz Work Horse ADCP and two RBRsolo3 D wave16 pressure loggers. The comparison period between 8th August – 12th October 2019 provides both the shallowest and longest continuous published comparison undertaken with the Spotter buoy.Strong agreement was evident between the Spotter buoy and RDI ADCP of key wave parameters including the significant wave height, peak wave period, and mean wave direction, with the mean values of those parameters across the full deployment period agreeing within 3%. Surface wave spectra and directional spectra are also analyzed with good agreement observed over the majority of the frequency domain, although the Spotter buoy records approximately 17% less energy within a narrow frequency band near the peak frequency when compared to the RDI ADCP. Measurements derived from the pressure loggers routinely underestimated the significant wave height and overestimated the mean wave period over the deployment period. The comparison highlights the suitability of the Spotter buoy for low-cost wave resource studies, with accurate measurements of key parameters and spectra observed.

Wave Induced Hydraulic Pressure by Wave Conditions of Pontoon Typed Floating Structures

2011 ◽  
Vol 250-253 ◽  
pp. 1444-1447
Author(s):  
Youn Ju Jeong ◽  
Young Jun You ◽  
Yoon Koog Hwang
Keyword(s):  
Wave Height ◽  
Experimental Studies ◽  
Type A ◽  
Wave Period ◽  
Small Scale ◽  
Hydraulic Pressure ◽  
Floating Structures ◽  
Wave Conditions ◽  
Wave Induced

In this study, in order to verify wave induced buoyancy effects by wave conditions of wave height and period, experimental studies were conducted to the floating structures of pontoon type. A series of small-scale tests with various wave cases were performed to the pontoon models. Two small-scale pontoon models having different bottom details were fabricated and tested under the five different wave cases. Six hydraulic pressure gauges were attached on the bottom of pontoon models and wave induced hydraulic pressure was measured during the tests. Finally, hydraulic pressure subjected to the bottom of pontoon models were compared with each other. As the results of this study, it was found that wave induced hydraulic pressures at bottom were dependent on the wave period as well as wave height, and waffled bottom shape hardly influenced on wave induced hydraulic pressure.

scholarly journals Brief communication: Characteristic properties of extreme wave events in the Baltic Sea

2017 ◽  
Author(s):  
Jan-Victor Björkqvist ◽  
Laura Tuomi ◽  
Niko Tollman ◽  
Antti Kangas ◽  
Heidi Pettersson ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Wave Height ◽  
Significant Wave Height ◽  
Wave Steepness ◽  
Extreme Wave ◽  
The Baltic Sea ◽  
Baltic Proper ◽  
Wave Conditions ◽  
The Baltic ◽  
Proper Wave

Abstract. A significant wave height of 7 m has been measured five times by the northern Baltic Proper wave buoy in the Baltic Sea, exceeding 8 m twice (2004 & 2017). We classified these storms into two groups by duration and wave steepness. Interestingly, the two highest events exhibited opposite properties, with the 2017 event being the longest storm on record. This storm is also the first where the harshest wave conditions were modelled to occur in the western part of the Baltic Proper. The metrics quantifying the storm's duration and steepness might aid in issuing warnings for extreme wave conditions.

scholarly journals Projected 21st century changes in extreme wind-wave events

2020 ◽  
Vol 6 (24) ◽  
pp. eaaz7295 ◽  
Author(s):  
Alberto Meucci ◽  
Ian R. Young ◽  
Mark Hemer ◽  
Ebru Kirezci ◽  
Roshanka Ranasinghe
Keyword(s):  
Wave Height ◽  
21St Century ◽  
Significant Wave Height ◽  
High Latitudes ◽  
Extreme Wave ◽  
Significant Wave ◽  
Statistical Confidence ◽  
The North ◽  
Wave Conditions ◽  
Projected Changes

We describe an innovative approach to estimate global changes in extreme wave conditions by 2100, as a result of projected climate change. We generate a synthetic dataset from an ensemble of wave models forced by independent climate simulation winds, enhancing statistical confidence associated with projected changes in extreme wave conditions. Under two IPCC representative greenhouse gas emission scenarios (RCP4.5 and RCP8.5), we find that the magnitude of a 1 in 100-year significant wave height (Hs) event increases by 5 to 15% over the Southern Ocean by the end of the 21st century, compared to the 1979–2005 period. The North Atlantic shows a decrease at low to mid latitudes (≈5 to 15%) and an increase at high latitudes (≈10%). The extreme significant wave height in the North Pacific increases at high latitudes by 5 to 10%. The ensemble approach used here allows statistical confidence in projected changes of extremes.

Systematically Varied Rogue Wave Sequences for the Experimental Investigation of Extreme Structure Behavior

2006 ◽  
Author(s):  
Gu¨nther F. Clauss ◽  
Christian E. Schmittner ◽  
Janou Hennig
Keyword(s):  
Wave Height ◽  
Rogue Wave ◽  
Wave Train ◽  
Weather Conditions ◽  
Offshore Structures ◽  
Severe Weather ◽  
Wave Profile ◽  
Bending Moments ◽  
Extreme Wave ◽  
Improved Design

For an improved design of ships and offshore structures with regard to their behavior under severe weather conditions, wave height and steepness as well as the shape of the wave profile have to be considered. In this paper, the extreme New Year Wave as documented in numerous publications is varied with respect to wave height and period. These varied wave sequences are realized and measured in a model tank and applied to the investigation of motions and bending moments of an FPSO ship. The results are compared to the responses in the original wave train. An investigation of the riskiness of extreme wave sequences in comparison with existing rules concludes the paper.

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