FEATURES OF THE NORTH SEA WATER SPREADING IN THE BORNHOLM BASIN BY MODEL RESULTS

2019 ◽  
Vol 47 (3) ◽  
pp. 233-245
Author(s):  
V. A. Tsarev ◽  
N. Kh. Ding
Keyword(s):  
North Sea ◽  
Sea Water ◽  
Computational Domain ◽  
Bornholm Basin ◽  
Salinity Field ◽  
The North ◽  
Density Flow ◽  
Vertical Grid ◽  
The North Sea ◽  
Basic Equations

With the help of mathematical modeling, the features of the distribution of North Sea waters in the Bornholm basin are considered on the example of a large inflow occurring in January 2003. For better resolution of bottom processes in the bottom density flow model, the computational domain is split vertically into bottom and overlying areas. In the lower region with a thickness of 20 m, the vertical grid spacing is 1 m. The basic equations of the model are transformed for each of the regions using σ-coordinate. According to the simulation results, the features of the distribution of North Sea water are highlighted, as well as the associated change in the salinity field in the overlying layer. Estimates of the possible influence of runoff currents on the distribution of North Sea waters are obtained.

scholarly journals An ensemble study of extreme storm surge related water levels in the North Sea in a changing climate

Ocean Science ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 369-378 ◽  
Author(s):  
A. Sterl ◽  
H. van den Brink ◽  
H. de Vries ◽  
R. Haarsma ◽  
E. van Meijgaard
Keyword(s):  
North Sea ◽  
Climate Model ◽  
Sea Water ◽  
Global Climate ◽  
Global Climate Model ◽  
Storm Surges ◽  
Water Levels ◽  
The North ◽  
Extreme Storm ◽  
The North Sea

Abstract. The height of storm surges is extremely important for a low-lying country like The Netherlands. By law, part of the coastal defence system has to withstand a water level that on average occurs only once every 10 000 years. The question then arises whether and how climate change affects the heights of extreme storm surges. Published research points to only small changes. However, due to the limited amount of data available results are usually limited to relatively frequent extremes like the annual 99%-ile. We here report on results from a 17-member ensemble of North Sea water levels spaning the period 1950–2100. It was created by forcing a surge model of the North Sea with meteorological output from a state-of-the-art global climate model which has been driven by greenhouse gas emissions following the SRES A1b scenario. The large ensemble size enables us to calculate 10 000 year return water levels with a low statistical uncertainty. In the one model used in this study, we find no statistically significant change in the 10 000 year return values of surge heights along the Dutch during the 21st century. Also a higher sea level resulting from global warming does not impact the height of the storm surges. As a side effect of our simulations we also obtain results on the interplay between surge and tide.

Pollution of the Outer Oslofjord

1991 ◽  
Vol 24 (10) ◽  
pp. 321-322
Author(s):  
Kjell Baalsrud
Keyword(s):  
North Sea ◽  
General Circulation ◽  
Sea Water ◽  
Sewage Treatment ◽  
Circulation Pattern ◽  
Polluted Water ◽  
The North ◽  
Recreation Area ◽  
The North Sea ◽  
Sill Depth

The Outer Oslofjord has recently been subject to concern. 1. The Inner Oslofjord. Covers an area of 193 km2, is 160 m deep and is separated from the Outer Oslofjord by the narrow Drøbak sound with a sill depth of less than 20 metres. This part of the Oslofjord constitutes an enclosed body of sea water, sensitive to pollution, receiving sewage from approximately 650,000 inhabitants. In spite of modern sewage treatment, the fjord still suffers torn eutrophication problems resulting in reduced oxygen in the deep water, and areas of anoxic bottom water. The fjord is an important recreation area. 2. The Outer Oslofjord. Recent findings indicate that eutrophication is slowly increasing. An increasing eutrophication of the Outer Oslofjord wil also increase the need (and cost) of better sewage treatment in the Inner Oslofjord. 3. The North Sea. The quality of the water in the Oslofjord area is also dependent on the water it receives from the Skagerrak. The Skagerrak water will periodically receive polluted water from the southern North Sea and Kattegat. When these episodes coincide with water renewals between the Oslofjord and the Skagerrak, the fjord will receive polluted water from other countries. The Oslofjord water will in turn discharge into the Skagerrak, but due to the general circulation pattern, this will mainly influence the Norwegian south-east coast.

scholarly journals Seasonal variations in the occurrence of Vibriovulnificusalong the Dutch coast

1994 ◽  
Vol 112 (2) ◽  
pp. 285-290 ◽  
Author(s):  
J. Veenstra ◽  
P. J. G. M. Rietra ◽  
J. M. Coster ◽  
E. Slaats ◽  
S. Dirks-Go
Keyword(s):  
Seasonal Variation ◽  
Water Temperature ◽  
North Sea ◽  
Seasonal Variations ◽  
Water Samples ◽  
Human Disease ◽  
Sea Water ◽  
Dutch Coast ◽  
The North ◽  
The North Sea

SUMMARYThe seasonal variation in the occurrence ofV. vulnificusin relation to water temperature and salinity was studied along the Dutch coast. In two consecutive yearsV. vulnificusstrains could be isolated in August when the water temperature was highest. The indole-positive strains isolated from North Sea water samples were identical to most strains isolated from human disease and from the environment. However, strains isolated from four of five patients living in countries around the North Sea were different from the North Sea isolates in that they were indole-negative and have a lower NaCl tolerance.

Annual and spatial variability in endo- and ectoparasite infections of North Sea cod (Gadus morhua Linnaeus, 1758) larvae, post-larvae and juveniles

2014 ◽  
Vol 59 (2) ◽  
Author(s):  
Foojan Mehrdana ◽  
Qusay Bahlool ◽  
Alf Skovgaard ◽  
Jesper Kuhn ◽  
Per Kania ◽  
...  
Keyword(s):  
Spatial Variability ◽  
North Sea ◽  
Gadus Morhua ◽  
Sea Water ◽  
Atlantic Cod ◽  
The North ◽  
Infection Pressure ◽  
High Prevalence ◽  
Atlantic Cod Larvae ◽  
The North Sea

AbstractA parasitological investigation was performed on a total of 5380 Atlantic cod larvae, post-larvae and small juveniles sampled from the North Sea during a period of five years. The copepod Caligus elongatus (Von Nordmann, 1832) and the nematode Hysterothylacium aduncum (Rudolphi, 1802) were found at a relatively high prevalence of infection (4.6% and 5.2%, respectively). The infection by both parasites showed annual and spatial variability. C. elongatus showed a higher prevalence in 1992 compared to the following years, whereas the prevalence of H. aduncum increased from 1992 to 2001.We observed a relation between parasite distribution and parameters such as latitude and water depth. Adult digeneans (Lecithaster gibbosus and Derogenes varicus) and larval cestodes were also found with lower infection rates. Since changes of infection levels coincided with increasing North Sea water temperature in the studied period, it is hypothesized that temperature may affect parasite population levels. However, it is likely that other environmental factors may contribute to the observed variations. Absence of infection intensities higher than one nematode per fish in small larvae and post-larvae suggests that host survival may be affected by a high infection pressure. The relatively high levels of infection in the younger stages of cod, and the annual/spatial variability of these infections should be considered in the understanding of the early life dynamics of the species.

The North Sea: an overview

1987 ◽  
Vol 316 (1181) ◽  
pp. 461-485 ◽  
Keyword(s):  
Trace Metals ◽  
Organic Compounds ◽  
North Sea ◽  
Human Activities ◽  
Sea Water ◽  
Sea Floor ◽  
Natural Systems ◽  
The North ◽  
The North Sea ◽  
Trace Constituents

An overview is given of the natural systems of the North Sea: water-circulation, topography and geology of the sea floor, sediment transport, influx of trace constituents (nutrients, trace metals, organic compounds), biological systems and their interrelations. The effects of pollution and other human activities are discussed as well as the difficulties in assessing them where they are obscured by natural changes.

Quantitative studies on the marine Phycomycetes between Fladenground and the mouth of the River Tay

1980 ◽  
Vol 78 (3-4) ◽  
pp. s131-s131
Author(s):  
S. Raghu Kumar
Keyword(s):  
Surface Water ◽  
North Sea ◽  
Sea Water ◽  
Seasonal Fluctuation ◽  
Fungal Population ◽  
The North ◽  
Quantitative Studies ◽  
The North Sea ◽  
Very High ◽  
High Seas

SynopsisQuantitative studies on marine Phycomycetes (thraustochytrids) were carried out at 6 stations between the Fladenground area of the North Sea and the mouth of the River Tay, between September 1975 and September 1976. Five samplings were made of the surface water and the sediment during this period. The number of fungi/litre sea water or sediment increased with the proximity to the mouth of the river compared to the high seas. The fungal population exhibited a seasonal fluctuation, a high number occurring in September and an extremely low number occurring in March. The sediments revealed a very high number of propagules/litre (up to 73,000) compared to the water (up to 384).

scholarly journals Numerical modelling of physical processes governing larval transport in the Southern North Sea

2013 ◽  
Vol 10 (5) ◽  
pp. 1765-1806 ◽  
Author(s):  
M. C. H. Tiessen ◽  
L. Fernard ◽  
T. Gerkema ◽  
J. van der Molen ◽  
P. Ruardij ◽  
...  
Keyword(s):  
North Sea ◽  
Sea Water ◽  
A Priori ◽  
Three Dimensional ◽  
Larval Transport ◽  
Absolute Amount ◽  
Annual Variability ◽  
The North ◽  
The North Sea ◽  
Selection Of

Abstract. A three-dimensional hydrodynamic model (GETM) was coupled with a particle tracking routine (GITM) to study the inter-annual variability in transport paths of particles in the North Sea and English Channel. For validation, a comparison with observed drifter trajectories was made. The aim was to investigate to what extent variability in the hydrodynamic conditions alone (reflecting passive particle transport) contributed to inter-annual variability in transport of eggs and larvae. In this idealized study, no a-priori selection of spawning grounds or periods was made and no active behaviour (vertical migration) or mortality were included. Egg and larval development towards coastal nursery areas was based solely on sea water temperature, while settlement areas were defined by a threshold water depth. Results showed strong inter-annual variability in drift direction and distance, caused by a combination of wind speed and direction. Strong inter-annual variability was observed both in absolute amount of settlement in coastal areas, as well as in the relative importance of the different areas. Settlement in the western Dutch Wadden Sea not only showed inter-annual variability, but patterns were also variable within each year and revealed seasonal changes in the origin of particles.

A satellite-based Lagrangian view on the origin of water-masses in the northern European shelf seas

2021 ◽  
Author(s):  
Ezra Eisbrenner ◽  
Léon Chafik
Keyword(s):  
North Sea ◽  
Water Mass ◽  
Sea Water ◽  
Water Masses ◽  
Subpolar Gyre ◽  
The North ◽  
Shelf Seas ◽  
Shelf Sea ◽  
The North Sea ◽  
Northern North Sea

<p>Knowledge about water-mass properties is critical to understanding how ocean climate variability impacts the shelf seas. Disentangling the origin of shelf sea water-masses and associated driving mechanisms is, therefore, a significant step towards improving the predictive skill related to water-mass evolution. Especially more conservative water-mass properties, even of surface waters, have the potential to reveal links between the shelf seas and large-scale ocean circulation regimes when traced back to their origin. The northern North Sea for example as the main gateway for water-masses to one of Europe's largest shelf sea areas is largely supplied by water-masses from the open North Atlantic, a connection which can be seen from, e.g., sea surface salinity.</p><p>The aim of this study is to identify the origin of northern North Sea water-masses and distinguish pathway variability relative to the subpolar gyre regimes. This is done using Lagrangian trajectories, calculated using satellite-derived velocity fields. The results of the Lagrangian statistics mainly indicate that on inter-annual time-scales the North Atlantic subpolar gyre strength largely influences the water-masses found in the North Sea. The relation is found to originate from varying pathways and therefore origin. We conclude that on inter-annual time scales the subpolar gyre strength is a good proxy and skillful predictor of water-mass variability in the North Sea.</p>

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