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On the possibility of convective overturning in the Slupsk Furrow overflow of the Baltic Sea

100%

Zhurbas V., Elken J., Paka V., Piechura J., Chubarenko I., Vali G., Golenko N., Shchuka S.

Oceanologia

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2011

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tom 53

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nr 3

Closely spaced CTD transects across the Słupsk Furrow displayed a ‘downward- bending’ of salinity contours below the salinity interface on the southern flank due to a transverse circulation in the saline water overflow. Numerical simulation of a gravity current in an idealized channel with geometry, dimensions and initial density stratification all much the same as in the Słupsk Furrow was applied to verify whether the downward-bending could be transformed into an inverted density stratification. Some arguments in favour of the possibility of convective overturning due to the differential transverse advection beneath the gravity current, brought on by the numerical simulations, are discussed.

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Diurnal variations in nitrogen, phosphorus and iron compounds in the Southern Baltic Sea

100%

Sikorowicz G., Falkowska L., Burska D., Dunajska D., Pryputniewicz D., Magulski R., Lewandowska A.

Oceanologia

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2005

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tom 47

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nr 2

In order to assess their short-term variability, nutrient concentrations were measured at standard depths at 2 h intervals in the deepest region of the Gdańsk Deep during the first ten days of June 2001. The mean concentrations of nutrients in the euphotic zone were: NN (NO2 −, NO3 −, NH4 +) – 1.93 μmol dm−3, PO4 3− – 0.12 μmol dm−3 and Fetot – 0.11 μmol dm−3. During daylight hours, when the rate of assimilation was fastest, concentrations of nitrogen, phosphorus and iron compounds were very low. The phosphate concentration fell to a minimum (0.03 μmol dm−3) between 04:00 and 10:00 hrs, while total iron dropped to 0.01 μmol dm−3 between 10:00 and 16:00 hrs. Both levels were below the limiting values for phosphorus and iron. At night, concentrations of NO3 − and PO4 3− rose by 25%, those of NH4 + and Fetot by 35%. The mean molar ratios of NN:PO4 3− and Fetot:PO4 3− in the surface layer were subject to significant daily fluctuations. The molar NN:PO4 3− ratio was higher than the optimum value established for the Baltic Sea. Below the halocline, the concentrations of dissolved iron and phosphorus rose as a result of diffusion from sediments in response to changing redox conditions.

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Influence of density stratification on effluent plume dynamics

80%

Loncar G., Paklar G. B., Janekovic I.

Oceanologia

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2011

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tom 53

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nr 2

In this study we modelled sea temperature (T ), salinity (S) and density field dynamics using a 3D numerical model applied to Rijeka Bay (Croatia) in order to explore their effect on effluent plume dynamics in the vicinity of four submarine sewage outfalls when the bora wind (NE direction) is blowing. The vertical density stratification in the area studied is strongly related to the bora wind, which contributes significantly to the lowering of the pycnocline depth through enhanced mixing in the vertical, giving rise to changes in the neutral buoyancy level. The features of near-field plume dynamics were calculated with the use of a separate near-field numerical model, using information on the vertical density distribution previously calculated using a 3D numerical model. The results of the numerical simulations and statistical analysis of the wind data indicate a very low probability of complete water column homogenization and consequent effluent plume rise to the sea surface under the influence of the bora wind during the peak tourist season (May–September).

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Short-term changes in the hydrochemical constituents in the water column of the Gdansk Deep [Baltic Sea] in spring. Part 1. Nutrient and oxygen concentrations in relation to the density stratification

80%

Falkowska L., Burska D., Bolalek J., Roguszczak D.

Oceanologia

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1998

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tom 40

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nr 2

Ograniczanie wyników

4 Oceanologia

2 Burska D.

2 Falkowska L.

1 Bolalek J.

1 Chubarenko I.

1 Dunajska D.

1 Elken J.

1 Golenko N.

1 Janekovic I.

1 Lewandowska A.

1 Loncar G.

1 Magulski R.

1 Paka V.

1 Paklar G. B.

1 Piechura J.

1 Pryputniewicz D.

1 Roguszczak D.

1 Shchuka S.

1 Sikorowicz G.

1 Vali G.

1 Zhurbas V.

2 2011

1 2005

1 1998

On the possibility of convective overturning in the Slupsk Furrow overflow of the Baltic Sea

Diurnal variations in nitrogen, phosphorus and iron compounds in the Southern Baltic Sea

Influence of density stratification on effluent plume dynamics

Short-term changes in the hydrochemical constituents in the water column of the Gdansk Deep [Baltic Sea] in spring. Part 1. Nutrient and oxygen concentrations in relation to the density stratification