Long-term decline of the canopy-forming algae Gelidium corneum , associated to extreme wave events and reduced sunlight hours, in the southeastern Bay of Biscay

2018 ◽  
Vol 205 ◽  
pp. 152-160 ◽  
Author(s):  
Angel Borja ◽  
Guillem Chust ◽  
Almudena Fontán ◽  
Joxe Mikel Garmendia ◽  
María C. Uyarra
Keyword(s):  
Bay Of Biscay ◽  
Extreme Wave ◽  
Sunlight Hours

scholarly journals Extreme Wave Storms and Atmospheric Variability at the Spanish Coast of the Bay of Biscay

Atmosphere ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 316 ◽  
Author(s):  
Domingo Rasilla ◽  
Juan García-Codron ◽  
Carolina Garmendia ◽  
Sixto Herrera ◽  
Victoria Rivas
Keyword(s):  
Low Frequency ◽  
Bay Of Biscay ◽  
Extreme Wave ◽  
Atmospheric Variability ◽  
Spatial And Temporal Scales ◽  
Teleconnection Patterns ◽  
Spanish Coast ◽  
Pressure Anomaly ◽  
Anomaly Index

This paper examines the characteristics and long-term variability of storminess for the Spanish coast of the Bay of Biscay for the period 1948 to 2015, by coupling wave (observed and modelled) and atmospheric datasets. The diversity of atmospheric mechanisms that are responsible for wave storms are highlighted at different spatial and temporal scales: synoptic (cyclone) and low frequency (teleconnection patterns) time scales. Two types of storms, defined mostly by wave period and storm energy, are distinguished, resulting from the distance to the forcing cyclones, and the length of the fetch area. No statistically significant trends were found for storminess and the associated atmospheric indices over the period of interest. Storminess reached a maximum around the decade of the 1980s, while less activity occurred at the beginning and end of the period of study. In addition, the results reveal that only the WEPI (West Europe Pressure Anomaly Index), EA (Eastern Atlantic), and EA/WR (Eastern Atlantic/Western Russia) teleconnection patterns are able to explain a substantial percentage of the variability in storm climate, suggesting the importance of local factors (W-E exposition of the coast) in controlling storminess in this region.

scholarly journals Long-term spatial variations in the Baltic Sea wave fields

Ocean Science ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 141-150 ◽  
Author(s):  
T. Soomere ◽  
A. Räämet
Keyword(s):  
Baltic Sea ◽  
Spatial Variations ◽  
Extreme Wave ◽  
The Baltic Sea ◽  
Wave Fields ◽  
Wave Heights ◽  
The Baltic ◽  
Wave Properties ◽  
Sea Wave

Abstract. This study focuses on spatial patterns in linear trends of numerically reconstructed basic wave properties (average and extreme wave heights, wave periods) in the Baltic Sea under the assumption of no ice cover. Numerical simulations of wave conditions for 1970–2007, using the WAM wave model and adjusted geostrophic winds, revealed extensive spatial variations in long-term changes in both average and extreme wave heights in the Baltic Sea but almost no changes in the basinwide wave activity and wave periods. There has been a statistically significant decrease in the annual mean significant wave height by more than 10% between the islands of Öland and Gotland and in the southward sea area, and a substantial increase to the south-west of Bornholm, near the coast of Latvia, between the Åland Archipelago and the Swedish mainland, and between the Bothnian Sea and the Bothnian Bay. Variations in extreme wave heights (defined as the threshold for 1% of the highest waves each year) show similar patterns of changes. In several areas the trends in average and extreme wave heights are different. Such a complicated pattern of changes indicates that (i) different regions of the Baltic Sea basin have experienced widespread but essentially different changes in wind properties and (ii) many seemingly controversial trends and variations established in wave properties at different sites in the recent past may reflect the natural spatial variability in the Baltic Sea wave fields.

scholarly journals Long-term dietary segregation of common dolphins Delphinus delphis in the Bay of Biscay, determined using cadmium as an ecological tracer

2005 ◽  
Vol 305 ◽  
pp. 275-285 ◽  
Author(s):  
V Lahaye ◽  
P Bustamante ◽  
J Spitz ◽  
W Dabin ◽  
K Das ◽  
...  
Keyword(s):  
Bay Of Biscay ◽  
Delphinus Delphis ◽  
Common Dolphins

Random Waves and Capsize Probability Based on Large Amplitude Motion Analysis

2002 ◽  
Author(s):  
Jan O. de Kat ◽  
Dirk-Jan Pinkster ◽  
Kevin A. McTaggart
Keyword(s):  
Time Domain ◽  
Random Waves ◽  
Extreme Wave ◽  
Small Probability ◽  
Safe Operation ◽  
Short Term ◽  
Physical Behavior ◽  
Wind Climate ◽  
Large Amplitude Motion

The objective of this paper is to apply a methodology aimed at the probabilistic capsize assessment of two naval ships: a frigate and a corvette. Use is made of combined knowledge of the wave and wind climate a ship will be exposed to during its lifetime and of the physical behavior of that ship in the various sea states it is likely to encounter. This includes the behavior in extreme wave conditions that have a small probability of occurrence, but which may be critical to the safe operation of a ship. Time domain simulations provide the basis for deriving short-term and long-term statistics for extreme roll angles. The numerical model is capable of predicting the 6 DOF behavior of a steered vessel in wind and waves, including conditions that may lead to broaching and capsizing.

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.

Extreme Waves of Sea Storms

2010 ◽  
Author(s):  
Francesco Fedele ◽  
Felice Arena ◽  
M. Aziz Tayfun
Keyword(s):  
Stochastic Model ◽  
Power Law ◽  
Analytical Solutions ◽  
Return Periods ◽  
Extreme Waves ◽  
Extreme Wave ◽  
Relative Validity ◽  
Wave Measurements ◽  
Storm Model

We present a stochastic model of sea storms for describing long-term statistics of extreme wave events. The formulation generalizes Boccotti’s equivalent triangular storm model (Boccotti 2000) by describing an actual storm history in the form of a generic power law. The latter permits the derivation of analytical solutions for the return periods of extreme wave events and associated statistical properties. Finally, we assess the relative validity of the new model and its predictions by analyzing wave measurements retrieved from two NOAA-NODC buoys in the Atlantic and Pacific Oceans.

scholarly journals Evaluation of extreme wave probability on the basis of long-term data analysis

Ocean Science ◽  
2018 ◽  
Vol 14 (5) ◽  
pp. 1321-1327 ◽  
Author(s):  
Kirill Bulgakov ◽  
Vadim Kuzmin ◽  
Dmitry Shilov
Keyword(s):  
Wave Height ◽  
Wind Wave ◽  
Cumulative Probability ◽  
Extreme Waves ◽  
Model Data ◽  
Extreme Wave ◽  
Method Of Calculation ◽  
Wave Heights ◽  
Term Data

Abstract. A method of calculation of wind wave height probability based on the significant wave height probability is described (Chalikov and Bulgakov, 2017). The method can also be used for estimation of the height of extreme waves of any given cumulative probability. The application of the method on the basis of long-term model data is presented. Examples of averaged annual and seasonal fields of extreme wave heights obtained using the above method are given. Areas where extreme waves can appear are shown.

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