Performance of WAVEWATCH-III and SWAN Models in the North Sea

2018 ◽  
Author(s):  
Sonia Ponce de León ◽  
J. Bettencourt ◽  
G. Ph. Van Vledder ◽  
P. Doohan ◽  
C. Higgins ◽  
...  
Keyword(s):  
North Sea ◽  
Wave Spectrum ◽  
Point Of View ◽  
Wave Direction ◽  
Ocean Engineering ◽  
Wind Fields ◽  
Peak Period ◽  
Wavewatch Iii ◽  
The North ◽  
The North Sea

This paper presents the hindcast of the winter of 2013 in the North Sea using two wave models: WAVEWATCH-III (WW3) and SWAN. The performance of the WW3 and SWAN models was assessed for this winter, when successive storms hit the hindcast area in a short time period, and examined in terms of the averaged wave parameters (Hs, peak period and wave direction) and the power wave spectrum. The assessment was made from an operational point of view. Possible effects of the accuracy of the wind fields, the physics chosen in each model and numerical settings are discussed. We elaborate on efficiency, accuracy and grid issues for both models, aiming to provide guidelines for ocean engineering wave forecasts.

Prediction of Relative Motion and Probability of Contact Between FPSO and Shuttle Tanker in Tandem Offloading Operation

2002 ◽  
Author(s):  
Haibo Chen ◽  
Torgeir Moan ◽  
Sverre Haver ◽  
Kjell Larsen
Keyword(s):  
North Sea ◽  
Extreme Values ◽  
Simulation Models ◽  
Point Of View ◽  
Simulation Code ◽  
The North ◽  
Simulation Based ◽  
The North Sea ◽  
Sensitivity Studies ◽  
Tandem Offloading

Tandem offloading safety between FPSO and shuttle tanker is under concern. A few collisions between the two vessels have happened in the North Sea in recent years. In these incidents, excessive relative motions (termed as surging and yawing in this paper) between FPSO and tanker are identified as “failure prone situations” which have contributed to the initiation of most collision incidents. To quantitatively assess the probability of surging and yawing events, and more importantly, to effectively reduce their occurrence in tandem offloading operation, we present a simulation-based approach in this paper, which is carried out by a state-of-the-art time-domain simulation code SIMO. The SIMO simulation models are setup and calibrated for a typical North Sea purpose-built FPSO and a DP shuttle tanker. This 2-vessel system motion in tandem offloading is simulated. The simulated relative distance and relative heading between FPSO and tanker are analyzed by fitting their extreme values into statistical models. This gives out probabilities of surging and yawing events. Sensitivity studies are performed to analyze contributions from various technical and operational factors. Measures to minimize the occurrence of surging and yawing from design and operational point of view are proposed.

Danish–German–Dutch Wadden Environments

2005 ◽  
Author(s):  
Jacobus Hofstede
Keyword(s):  
Present State ◽  
North Sea ◽  
Energy Input ◽  
Wadden Sea ◽  
Wind Waves ◽  
Tidal Energy ◽  
Point Of View ◽  
Energy Impact ◽  
The North ◽  
The North Sea

The Wadden Sea environment is a coastal tidal environment situated between the North Sea and the northwestern European Lowlands. It stretches over a distance of about 450 km from Den Helder in The Netherlands to the peninsula of Skallingen in Denmark. The approximately 10,000 km2 large Wadden Sea is a coastal sediment sink that developed in the course of the Holocene transgression. It resulted from a specific combination of sediment availability (mainly from the North Sea) and a hydrodynamic regime of tides and waves. In its present state, the Wadden Sea environment consists of extensive tidal flats (the wadden), tidal gullies and inlets, salt marshes, and about twenty-four sandy barrier islands. Further, four estuaries exist that discharge into the Wadden Sea. The Wadden Sea may best be characterized by the words ‘dynamic’ and ‘extreme’; dynamic from a geo-morphological point of view, extreme in its biology. According to Spiegel (1997), with each flood phase a tidal energy input in the order of 2.2 thousand MW occurs in the Wadden Sea of Schleswig-Holstein (Germany). This energy input, combined with the energy impact of wind, waves, and storm surges, results in strong morphological processes. Flora and fauna in the Wadden Sea have to adapt to these intense morphodynamics. Further, they have to endure the permanent change of flood and ebb and fluctuations in salinity, as well as high water temperatures during summer and occasional ice cover during winter. As a result of these extreme environmental conditions, a highly specialized biosystem with about 4,800 species has developed (Heydemann 1998). In its present state the Wadden Sea is one of the last remaining near-natural large-scale ecosystems in central Europe. Its ecological significance is underlined by the fact that 250 animal species live exclusively here (Heydemann 1998). Furthermore, nowhere else in Europe is an ecosystem of this size visited by more birds per surface area for the purpose of feeding. However, the Wadden Sea is subjected to considerable human influences, e.g. the input of nutrients and pollutants, fisheries, dredging, boat traffic, and tourism (de Jong et al. 1999).

scholarly journals JOINT OFFSHORE WIND FIELD MONITORING WITH SPACEBORNE SAR AND PLATFORM-BASED DOPPLER LIDAR MEASUREMENTS

2015 ◽  
Vol XL-7/W3 ◽  
pp. 959-966 ◽  
Author(s):  
S. Jacobsen ◽  
S. Lehner ◽  
J. Hieronimus ◽  
J. Schneemann ◽  
M. Kühn
Keyword(s):  
North Sea ◽  
Wind Field ◽  
Wind Farm ◽  
Offshore Wind ◽  
Small Scale ◽  
Doppler Lidar ◽  
Wind Fields ◽  
The North ◽  
Spatial Coverage ◽  
The North Sea

The increasing demand for renewable energy resources has promoted the construction of offshore wind farms e.g. in the North Sea. While the wind farm layout consists of an array of large turbines, the interrelation of wind turbine wakes with the remaining array is of substantial interest. The downstream spatial evolution of turbulent wind turbine wakes is very complex and depends on manifold parameters such as wind speed, wind direction and ambient atmospheric stability conditions. <br><br> To complement and validate existing numerical models, corresponding observations are needed. While in-situ measurements with e.g. anemometers provide a time-series at the given location, the merits of ground-based and space- or airborne remote sensing techniques are indisputable in terms of spatial coverage. Active microwave devices, such as Scatterometer and Synthetic Aperture Radar (SAR), have proven their capabilities of providing sea surface wind measurements and particularly SAR images reveal wind variations at a high spatial resolution while retaining the large coverage area. Platform-based Doppler LiDAR can resolve wind fields with a high spatial coverage and repetition rates of seconds to minutes. In order to study the capabilities of both methods for the investigation of small scale wind field structures, we present a direct comparison of observations obtained by high resolution TerraSAR-X (TS-X) X-band SAR data and platform-based LiDAR devices at the North Sea wind farm alpha ventus. We furthermore compare the results with meteorological data from the COSMO-DE model run by the German Weather Service DWD. Our study indicates that the overall agreement between SAR and LiDAR wind fields is good and that under appropriate conditions small scale wind field variations compare significantly well.

Use of Spaceborne Synthetic Aperture Radar for Offshore Wave Analysis

2004 ◽  
Author(s):  
Jose´ C. Nieto-Borge ◽  
Susanne Lehner ◽  
Tobias Schneiderhan ◽  
Johannes Schulz-Stellenfleth ◽  
Andreas Niedermeier
Keyword(s):  
Synthetic Aperture Radar ◽  
North Sea ◽  
Wave Spectrum ◽  
Surface Wind ◽  
Global Scale ◽  
Synthetic Aperture ◽  
Sar Images ◽  
The North ◽  
The North Sea ◽  
Aperture Radar

Spaceborne Synthetic Aperture Radar (SAR) is able to provide sea state information on a global scale by means of the directional wave spectrum. Recent developed algorithms have been developed to obtain additional information in the spatial domain rather than the spectral domain. These methods permit to detect of individual wave heights, wave groupiness in open sea areas, as well as surface wind fields. This work shows the capabilities of spaceborne SAR to extract offshore information about individual waves and wave grouping for areas of about 100 × 100 square kilometers. The methods are applied to ERS-2 SAR images of the North Sea over areas close to the location of some oil platforms. Results obtained in the vicinity of the Ekofisk platform are shown. In addition, ERS-2 SAR images taken on January 1, 1995 over the Draupner platform in the North Sea are analyzed. These SAR images were taken at the approximate time when the wave record known as “new year wave” was measured.

scholarly journals ROMS Based Hydrodynamic Modelling Focusing on the Belgian Part of the Southern North Sea

2021 ◽  
Vol 9 (1) ◽  
pp. 58
Author(s):  
Georgios Klonaris ◽  
Frans Van Eeden ◽  
Jeffrey Verbeurgt ◽  
Peter Troch ◽  
Denis Constales ◽  
...  
Keyword(s):  
Numerical Model ◽  
North Sea ◽  
Three Dimensional ◽  
Water Levels ◽  
Ocean Modeling ◽  
Added Value ◽  
Wind Fields ◽  
Regional Ocean Modeling System ◽  
The North ◽  
The North Sea

The North Sea is a shallow sea that forms a complex physical system. The nonlinear interaction of the astronomical tides, varying wind fields and varying pressure systems requires appropriate approaches to be described accurately. An application based on the advanced numerical model Regional Ocean Modeling System (ROMS) was newly developed by the authors, tailored to simulate these hydrodynamic processes in the North Sea and the Belgian Continental Shelf, which is the area of particular interest in the present study. The purpose of this work is to develop and validate a state-of-the-art three-dimensional numerical model to form the basis of a compound operational and forecasting tool for the Belgian coastal zone. The model was validated with respect to water levels and temperature. Validation for astronomical tides was accomplished through the comparison of the principal constituents between the model results and observations at a number of tidal gauges in Belgium and other countries. A statistical analysis of the results showed that the model behaves as expected throughout the North Sea. The model response to the varying meteorological conditions was also validated using hindcast data for 2011 as input. In this case, the comparison between observed and modelled water levels showed a good agreement with average RMSE in Belgium 9.5 cm. Overall, the added value of this work is the development of an independent model for validation and comparison with other models and which can be used as an efficient tool for operational and forecasting purposes.

XVI.—The Macrofauna of the Intertidal Sand of Kames Bay, Millport, Buteshire

1942 ◽  
Vol 60 (2) ◽  
pp. 543-561 ◽  
Author(s):  
E. Emrys Watkin
Keyword(s):  
North Sea ◽  
Soil Fauna ◽  
Point Of View ◽  
Intertidal Sand ◽  
Number Of Species ◽  
The North ◽  
Intertidal Species ◽  
South Wales ◽  
Ecological Problems ◽  
The North Sea

During the last few years the distribution of the macrofauna, and to a less extent the microfauna, of the intertidal soils of the shores of Britain has received considerable attention and the principle that the species show a zonation with maximum densities at certain levels is now well established. The extensive studies of Elmhirst (1931) and of Stephen (1928, 1929, and 1930) on the fauna of the sandy and muddy areas of numerous Scottish bays has laid the foundation for much further work in this area. Pirrie, Bruce, and Moore (1932) have described the zonation of the fauna in the intertidal sand of Port Erin bay. Alexander, Southgate, and Bassindale (1935) refer to the fauna of the sand at the mouth of the River Tees, but mainly from the point of view of comparison with the fauna of the estuary. Crawford (1937 a and b) gives notes on the distribution and habits of certain intertidal species in sandy bays and estuaries in west England and south Wales. Rees (1939) has surveyed in outline, as part of a study of the interstitial sand copepods, the macrofauna of some sandy bays in north Donegal. Spooner and Moore (1940) have given a detailed description of the zonation of the species in the estuarine muds of the Tamar. Apart from the above, reference must be made to two intensive studies on the soil fauna of the eastern shores of the North Sea, namely, that of Thamdrup (1935) on Danish shores and of Wohlenberg (1937) on certain bays on the island of Sylt. A general discussion of the ecological problems of sand, mud, and algal environments is given by Remane (1933), based on the macrofauna and microfauna of Kiel bay. He reaches the conclusion, based on the number of species which occur in each environment, that the macrofauna of sand is comparatively poor compared with mud.

XVI.—The Macrofauna of the Intertidal Sand of Kames Bay, Millport, Buteshire

1942 ◽  
Vol 50 (2) ◽  
pp. 543-561
Author(s):  
E. Emrys Watkin
Keyword(s):  
North Sea ◽  
Soil Fauna ◽  
Point Of View ◽  
Intertidal Sand ◽  
Number Of Species ◽  
The North ◽  
Intertidal Species ◽  
South Wales ◽  
Ecological Problems ◽  
The North Sea

During the last few years the distribution of the macrofauna, and to a less extent the microfauna, of the intertidal soils of the shores of Britain has received considerable attention and the principle that the species show a zonation with maximum densities at certain levels is now well established. The extensive studies of Elmhirst (1931) and of Stephen (1928, 1929, and 1930) on the fauna of the sandy and muddy areas of numerous Scottish bays has laid the foundation for much further work in this area. Pirrie, Bruce, and Moore (1932) have described the zonation of the fauna in the intertidal sand of Port Erin bay. Alexander, Southgate, and Bassindale (1935) refer to the fauna of the sand at the mouth of the River Tees, but mainly from the point of view of comparison with the fauna of the estuary. Crawford (1937 a and b)gives notes on the distribution and habits of certain intertidal species in sandy bays and estuaries in west England and south Wales. Rees (1939) has surveyed in outline, as part of a study of the interstitial sand copepods, the macrofauna of some sandy bays in north Donegal. Spooner and Moore (1940) have given a detailed description of the zonation of the species in the estuarine muds of the Tamar. A part from the above, reference must be made to two intensive studies on the soil fauna of the eastern shores of the North Sea, namely, that of Thamdrup (1935) on Danish shores and of Wohlenberg (1937) on certain bays on the island of Sylt. A general discussion of the ecological problems of sand, mud, and algal environments is given by Eemane (1933), based on the macrofauna and microfauna of Kiel bay. He reaches the conclusion, based on the number of species which occur in each environment, that the macrofauna of sand is comparatively poor compared with mud.

I—North Sea Oil

1974 ◽  
Vol 27 (2) ◽  
pp. 206-212
Author(s):  
T. F. Gaskell
Keyword(s):  
North Sea ◽  
Point Of View ◽  
Good Prospect ◽  
Severe Storms ◽  
New Developments ◽  
The North ◽  
Exploration And Production ◽  
The North Sea ◽  
Tidal Streams ◽  
Gas Fields

There have been many new developments in the North Sea during the last seven years since gas was first discovered in the B.P. West Sole field. First, half a dozen other gas-fields have been found and a large quantity of methane has already been piped to Britain. Secondly, oil has been discovered in the northern part of the North Sea between Scotland and Scandinavia. One may well ask why this large source of energy was not discovered many years ago. The reasons are much the same as applied to the gas discovery; the North Sea 10 years ago was not a very good prospect from a geological point of view, and in any case the techniques of exploration and production in offshore areas were not adequate until recently, especially in a place such as the North Sea wher severe storms and tidal streams make operations difficult and hazardous.

scholarly journals Assessing the Performance of the Dissipation Parameterizations in WAVEWATCH III Using Collocated Altimetry Data

2009 ◽  
Vol 39 (11) ◽  
pp. 2800-2819 ◽  
Author(s):  
Georgia D. Kalantzi ◽  
Christine Gommenginger ◽  
Meric Srokosz
Keyword(s):  
Wave Height ◽  
Wave Breaking ◽  
Source Term ◽  
Wave Spectrum ◽  
Wave Model ◽  
North Indian Ocean ◽  
Altimeter Data ◽  
Wave Direction ◽  
Wavewatch Iii ◽  
The North

Abstract Wave-breaking dissipation is one of the least understood processes implemented in contemporary wave models. Significant effort has been put in its parameterization, but it has not proven to be totally satisfactory, either theoretically or practically. In this work, the WAVEWATCH III (version 2.22; Tolman) wave model is used to evaluate the two wind input/dissipation source term packages that it includes: (i) Wave Model (WAM) cycle 3 (WAMDIG) and (ii) Tolman and Chalikov. Global model outputs were obtained under the same wind forcing for the two dissipation formulations and were collocated in space and time in the north Indian Ocean with Ocean Topography Experiment (TOPEX) altimeter data. The performance of the model was assessed by evaluating the statistical behavior of the collocated datasets. The parameters examined were significant wave height, wind speed, wind direction, wave direction, wave height for fully developed seas, and energy loss due to wave breaking. From the results, the behavior of the input/dissipation formulations in specific wind and wave conditions was identified; that is, the results give insight to the way the two source term packages “work” and how they respond to local wind sea or swell. Specifically, both of the packages were unable to perform adequately during a season when the area can be mostly affected by swell. However, the results confirmed that the examination of only integral spectral wave parameters does not give information on the inherent physical characteristics of the formulations. Further study, on the basis of point spectra, is necessary to examine the formulations’ performance across the wave spectrum.

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