scholarly journals Wave conditions in the Baltic Proper and in the Gulf of Finland during windstorm Gudrun

2008 ◽  
Vol 8 (1) ◽  
pp. 37-46 ◽  
Author(s):  
T. Soomere ◽  
A. Behrens ◽  
L. Tuomi ◽  
J. W. Nielsen
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Weather Forecast ◽  
Gulf Of Finland ◽  
Marine Research ◽  
Significant Wave ◽  
Baltic Proper ◽  
Wave Conditions ◽  
The Baltic ◽  
The Gulf Of Finland

Abstract. Wave conditions in the northern Baltic Proper during windstorm Erwin/Gudrun (January 2005) are analysed based on in situ measurements in three locations and output of operational wave models from the German Weather Forecast Service, the Danish Meteorological Institute and the Finnish Institute of Marine Research. The measured significant wave height reached 7.2 m in the northern Baltic Proper and 4.5 m in the Gulf of Finland. The roughest wave conditions, estimated from the comparison of the forecast and measured data, occurred remote from the sensors, off the coasts of Saaremaa and Latvia where the significant wave height was about 9.5 m. Peak periods exceeded 12 s in a large part of the northern Baltic Proper and in the central part of the Gulf of Finland.

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 Brief communication: Characteristic properties of extreme wave events observed in the northern Baltic Proper, Baltic Sea

2017 ◽  
Vol 17 (9) ◽  
pp. 1653-1658 ◽  
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 and 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.

Traffic on the Great Lakes and New Labrador Developments

1968 ◽  
Vol 5 (04) ◽  
pp. 347-373
Author(s):  
Robert B. Harris
Keyword(s):  
Great Lakes ◽  
Wave Height ◽  
Significant Wave Height ◽  
Design Criteria ◽  
Severe Storm ◽  
Significant Wave ◽  
Hood Canal ◽  
Floating Bridge ◽  
Wave Conditions

On 13 February 1979, the entire west span of the Hood Canal Floating Bridge sank under the action of a very severe storm. Although the significant wave height was estimated as high as 4.7 feet, wind and wave conditions during the storm were well within the design criteria of the bridge.

scholarly journals Better Baltic Sea wave forecasts: improving resolution or introducing ensembles?

Ocean Science ◽  
2018 ◽  
Vol 14 (6) ◽  
pp. 1435-1447
Author(s):  
Torben Schmith ◽  
Jacob Woge Nielsen ◽  
Till Andreas Soya Rasmussen ◽  
Henrik Feddersen
Keyword(s):  
Baltic Sea ◽  
Wave Height ◽  
Spectral Resolution ◽  
Significant Wave Height ◽  
Initial Conditions ◽  
A Priori ◽  
The Baltic Sea ◽  
Significant Wave ◽  
Operational Forecasts ◽  
The Baltic

Abstract. The performance of short-range operational forecasts of significant wave height (SWH) in the Baltic Sea is evaluated. Forecasts produced by a base configuration are intercompared with forecasts from two improved configurations: one with improved horizontal and spectral resolution and one with ensembles representing uncertainties in the physics of the forcing wind field and the initial conditions of this field. Both of the improved forecast classes represent an almost equal increase in computational costs. Therefore, the intercomparison addresses the question of whether more computer resources would be more favorably spent on enhancing the spatial and spectral resolution or, alternatively, on introducing ensembles. The intercomparison is based on comparisons with hourly observations of significant wave height from seven observation sites in the Baltic Sea during the 3-year period from 2015 to 2017. We conclude that for most wave measurement sites, the introduction of ensembles enhances the overall performance of the forecasts, whereas increasing the horizontal and spectral resolution does not. These sites represent offshore conditions, in that they are well exposed from all directions, are a large distance from the nearest coast and in deep water. Therefore, there is the a priori expectation that a detailed shoreline and bathymetry will not have any impact. Only at one site do we find that increasing the horizontal and spectral resolution significantly improves the forecasts. This site is situated in nearshore conditions, close to land and a nearby island, and is therefore shielded from many directions. Consequently, this study concludes that to improve wave forecasts in offshore areas, ensembles should be introduced. For near shore areas, in comparison, the study suggests that additional computational resources should be used to increase the resolution.

The significance of wave–current interaction on modelled wave fields in the Baltic Sea

2020 ◽  
Author(s):  
Hedi Kanarik ◽  
Laura Tuomi ◽  
Jan-Victor Björkqvist ◽  
Tuomas Kärnä ◽  
Antti Westerlund
Keyword(s):  
Baltic Sea ◽  
Wave Spectrum ◽  
Hydrodynamical Model ◽  
Gulf Of Finland ◽  
Surface Currents ◽  
The Baltic Sea ◽  
Notable Effect ◽  
Baltic Proper ◽  
The Baltic ◽  
The Gulf Of Finland

<p>Currents in the Baltic Sea are relatively weak and are thus often expected to have a negligible effect on sea surface waves. To evaluate the magnitude of wave–current interactions in the Baltic Sea, we ran the third generation wave model WAM with and without surface currents from the 3D hydrodynamical model Nemo4. The results showed that the currents have a notable effect on wave field only on rare occasions and that the effects are largest in coastal areas of the Baltic Proper, most notably in the western Gotland Basin, and the Gulf of Finland. The simulations showed that the currents in the Baltic Sea can cause differences of significant wave height up to tens of centimeters. More notable effect was the change in the peak of the wave spectrum from swell to wind driven waves and vice versa in some occasions. In our study w<span>e mostly focus on the events of strong wave–current interactions in the northern Baltic Proper and Gulf of Finland as we have measured wave spectra available from these locations. From the comparison with wave buoy measurements we see that implementing surface currents</span> <span>slightly improves the </span><span>m</span><span>odelled peak period in the Gulf of Finland.</span> <span>The Gulf of Finland is of special interest also because a group of ADCP’s were installed close to the wave buoy. The current measurements from these devices can therefore be used to evaluate the accuracy of the currents in the hydrodynamical model. </span></p>

scholarly journals Better Baltic Sea wave forecasts: Improving resolution or introducing ensembles?

2018 ◽  
Author(s):  
Torben Schmith ◽  
Jacob Woge Nielsen ◽  
Till Andreas Soya Rasmussen
Keyword(s):  
Baltic Sea ◽  
Wave Height ◽  
Spectral Resolution ◽  
Significant Wave Height ◽  
Initial Conditions ◽  
A Priori ◽  
The Baltic Sea ◽  
Significant Wave ◽  
Operational Forecasts ◽  
The Baltic

Abstract. The performance of short-range operational forecasts of significant wave height in the Baltic Sea in three different configurations is evaluated. Forecasts produced by a base configuration are inter-compared with forecasts from two improved configurations: one with improved horizontal and spectral resolution and one with ensembles representing uncertainties in the physics of the forcing wind field and the initial conditions of this field. Both the improved forecast classes represent an almost equal increase in computational costs. The inter-comparison therefore addresses the question: would more computer resources most favorably be spent on enhancing the spatial and spectral resolution or, alternatively, on introducing ensembles? The inter-comparison is based on comparisons with hourly observations of significant wave height from seven observation sites in the Baltic Sea during the three-year period 2015–2017. We conclude that for most stations, the introduction of ensembles enhances the overall performance of the forecasts, whereas increasing the horizontal and spectral resolution does not. These stations represent offshore conditions, well exposed from all directions with a large distance to the nearest coast and with a large water depth. Therefore, the detailed shoreline and bathymetry is also a priori not expected to have any impact. Only for one station, we find that increasing the horizontal and spectral resolution significantly improved the forecasts. This station is situated in nearshore conditions, close to land, with a nearby island and therefore shielded from many directions. This study therefore concludes that to improve wave forecasts in offshore areas, ensembles should be introduced, while for nearshore areas better resolution may improve results.

Extreme waves induced by cyclone Nargis at Myanmar coast: numerical modeling versus satellite observations

2021 ◽  
Author(s):  
Thit Oo Kyaw ◽  
Miguel Esteban ◽  
Martin Mäll ◽  
Tomoya Shibayama
Keyword(s):  
Wave Height ◽  
Significant Wave Height ◽  
Measurement Data ◽  
India Meteorological Department ◽  
High Energy ◽  
Significant Wave ◽  
Simulation Results ◽  
Wave Conditions ◽  
Offshore Wave ◽  
Cyclone Nargis

AbstractThe deltaic coast of Myanmar was severely hit by tropical cyclone Nargis in May 2008. In the present study, a top-down numerical simulation approach using the Weather Research and Forecasting (WRF) and Simulating WAves Nearshore (SWAN) models was conducted to study the meteorological and offshore wave characteristics of cyclone Nargis near the coast of Myanmar. The WRF simulation results agree well with the observed data from the India Meteorological Department. SWAN simulation results were compared with the WaveWatch 3 model by National Oceanic and Atmospheric Administration and validated against available measurement data from satellites. The model results show relatively good agreement, and hindcast with satellites data (significant wave height only) shows a correlation coefficient value of 0.89. The SWAN and satellite comparisons also show better fit for high wave conditions. The resulted maximum significant wave height of 7.3 m by SWAN is considerably higher in energy than the seasonal waves normally prevalent at Myanmar’s deltaic coast. The possibility of high energy waves due to cyclones should be considered during the design and operation of coastal and offshore projects in the area, particularly given the risks that climate change can intensify cyclones in the future. Since Myanmar lacks a dense network of in-situ observational stations, the methodology used in the current study presents the potential application of various numerical techniques and satellite data to estimate extreme wave conditions near the Myanmar coast.

scholarly journals Migratory connectivity of two Baltic Sea salmon populations: retrospective analysis using stable isotopes of scales

2013 ◽  
Vol 71 (2) ◽  
pp. 336-344 ◽  
Author(s):  
Jyrki Torniainen ◽  
Pekka J. Vuorinen ◽  
Roger I. Jones ◽  
Marja Keinänen ◽  
Stefan Palm ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Baltic Sea ◽  
Isotope Analysis ◽  
Gulf Of Finland ◽  
Migratory Connectivity ◽  
Baltic Proper ◽  
Feeding Area ◽  
The Baltic ◽  
The Gulf Of Finland

Abstract Torniainen, J., Vuorinen, P. J., Jones, R. I., Keinänen, M., Palm, S., Vuori, K. A. M., and Kiljunen, M. 2014. Migratory connectivity of two Baltic Sea salmon populations: retrospective analysis using stable isotopes of scales. – ICES Journal of Marine Science, 71: 336–344. Migratory connectivity refers to the extent to which individuals of a migratory population behave in unison, and has significant consequences for the ecology, evolution and conservation of migratory animals. We made a retrospective assessment of the migratory connectivity of River Simojoki and River Kymijoki populations of Atlantic salmon Salmo salar L. by using stable isotope analysis of archived scales to identify the final feeding areas used before ascending rivers for spawning. We also tested differences in migratory connectivity between wild and hatchery-reared salmon and compared Carlin-tag recoveries with salmon scale stable isotope analysis as methods for studying salmon migrations. Stable isotope (δ13C, δ15N) values from the last growth region of scales from salmon caught ascending their natal rivers were compared via discriminant analysis with those from scales of salmon caught in different Baltic Sea areas during 1989–2011. Most River Simojoki salmon had likely fed in the Baltic Proper (mean ± SD for ascending fish probability 0.59 ± 0.32) with secondary likely feeding areas in the Bothnian Sea (0.21 ± 0.26) and the Gulf of Finland (0.20 ± 0.27). Most River Kymijoki salmon had likely fed in the Gulf of Finland (0.71 ± 0.42) with the Baltic Proper (0.29 ± 0.41) a secondary feeding area. The results did not indicate the Bothnian Sea to be an important feeding area. The two salmon populations showed weak migratory connectivity and rather fixed areal preference throughout the record irrespective of wild or stocked origin. Although the results from the scale stable isotope analyses were broadly consistent with previously reported Carlin-tag recoveries, we argue that the stable isotope approach offers several important advantages in the study of salmon migratory behaviour.

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.

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