Oceanologia No. 47 (4) / 05

Contents

Papers

Papers


Sea surface temperature distribution during upwelling along the Polish Baltic coast
Oceanologia 2005, 47(4), 415-432

Adam Krężel, Michał Ostrowski, Maria Szymelfenig
Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: oceak@univ.gda.pl

Keywords: upwelling, Baltic, sea surface temperature, AVHRR

Received 21 February 2005, revised 26 September 2005, accepted 28 September 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
Among over 150 maps of sea surface temperature in the Polish Baltic coastal region derived from satellite data during the warm period of the year (April-October) in 2000-2002, 41 cases were noted where its distribution showed characteristic features indicating the occurrence of coastal upwelling. The fundamental parameters of range, probability of occurrence and temperature modification caused by water from deeper sea layers raised by an upwelling event and spreading across the surface were established for three regions (Hel, Łeba and Kołobrzeg). The Kołobrzeg upwelling region had the largest spatial range (up to 5000 km2). The region with the smallest spatial range (Hel, up to 1400 km2) had the largest surface temperature amplitude (to 14°C), the largest maximum temperature gradient (5°C km2) and the largest average sea surface temperature decrease in the centre in relation to the background value.
full, complete article (PDF - compatibile with Acrobat 3.0), 284 KB

Influence of coastal upwelling on chlorophyll a concentration in the surface water along the Polish coast of the Baltic Sea
Oceanologia 2005, 47(4), 433-452

Adam Krężel1,*, Lena Szymanek2, Łukasz Kozłowski1, Maria Szymelfenig1
1Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: oceak@univ.gda.pl
*corresponding author
2Sea Fisheries Institute,
ul. Kołłątaja 1, PL-81-332 Gdynia, Poland

Keywords: Baltic Sea, coastal upwelling, chlorophyll concentration, satellite remote sensing

Received 21 February 2005, revised 29 September 2005, accepted 30 September 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). The study was carried out with the consent of the Goddard DAAC team (SeaWiFS authorised user). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
Space-time variations in chlorophyll a (Chl a) concentrations in the surface water of upwelling regions along the Polish coast of the Baltic Sea were analysed. Carried out between 1998 and 2002 in the warmer season (from April till October), the measurements were targeted mainly at the Hel upwelling. Satellite-derived sea surface temperature (AVHRR) and Chl a data (SeaWiFS) were used. Generally speaking, the Chl a concentration increased in the upwelling plume, except along the Hel Peninsula, where two scenarios took place: a reduction in Chl a concentration in spring and an increase in autumn.
full, complete article (PDF - compatibile with Acrobat 3.0), 275 KB

 Coastal up- and downwelling in the southern Baltic
Oceanologia 2005, 47(4), 453-475

Marek Kowalewski, Michał Ostrowski
Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: ocemk@univ.gda.pl

Keywords: Baltic Sea, upwelling, downwelling, hydrodynamic modelling

Received 21 February 2005, revised 23 September 2005, accepted 28 September 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
A three-dimensional hydrodynamic model was used to determine 12 zones of up- and downwelling in the southern part of the Baltic Sea. On the basis of a seven-year numerical simulation, the annual frequency of up- and downwelling events in various regions was analysed, their vertical velocity evaluated and the probability of their occurrence for different wind directions calculated. Verification of the model results demonstrated their good correspondence with satellite images, on average equal to 92%. The poorest consistency was recorded for upwelling in the Bornholm region (81%). The annual average frequency of strong upwelling (velocities >10-4 m s-1) ranged from c. 5-7% off the eastern coasts of the southern Baltic to >31% along the north-eastern coast of Bornholm. Along the Polish coast (excepting the Vistula Spit) downwelling was recorded more frequently than upwelling. The frequency of strong vertical currents was highest in the area to the north of the Hel Peninsula, where high percentages of strong upwelling (27.1%) and downwelling (37.1%) were recorded.
full, complete article (PDF - compatibile with Acrobat 3.0), 1558 KB

 Ecohydrodynamic model of the Baltic Sea. Part 1. Description of the ProDeMo model
Oceanologia 2005, 47(4), 477-516

Bogdan Ołdakowski, Marek Kowalewski, Jan Jędrasik, Maria Szymelfenig
Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: ocemk@univ.gda.pl

Keywords: Baltic Sea, ecohydrodynamic modelling, biogeochemical processes, nutrients

Received 21 February 2005, revised 10 October 2005, accepted 20 October 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
The ProDeMo (Production and Destruction of Organic Matter Model), a 3D coupled hydrodynamic-ecological model, was formulated and applied to the whole Baltic Sea and the subregion of the Gulf of Gdansk. It describes nutrient cycles (phosphorus, nitrogen, silicon) through the food web with 15 state variables, oxygen conditions and the parameterisation of water-sediment interactions. The present version of the model takes two groups of phytoplankton - diatoms and non-diatoms - as well as zooplankton into consideration. It covers the flow of matter and energy in the sea, including river discharges and atmospheric deposition. Numerical applications are embedded on a 1 NM grid for the Gulf of Gdansk and a 5 NM grid for the Baltic Sea.
    Since the model results largely concur with observations, the model can be regarded as a reliable tool for analysing the behaviour of the Baltic ecosystem. Some examples of the spatial-temporal variability of the most important biological and chemical parameters are presented. The model results are compared with those of other modelling research in the Baltic Sea.
    Both the ProDeMo model algorithm and its computing procedures need to be further developed. The next version should therefore enable more phytoplankton groups to be defined, for example cyanobacteria, which are able to take up molecular nitrogen from the atmosphere (nitrogen fixation). Additionally, the sediment phase should be divided into active and non-active layers.
full, complete article (PDF - compatibile with Acrobat 3.0), 6987 KB

 Validation of hydrodynamic part of the ecohydrodynamic model for the southern Baltic
Oceanologia 2005, 47(4), 517-541

Jan Jędrasik
Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: janj@sat.ocean.univ.gda.pl

Keywords: Baltic Sea, hydrodynamic model, model validation

Received 21 February 2005, revised 28 October 2005, accepted 30 November 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
The first part of the Baltic Sea ecohydrodynamic model, based on the Princeton Ocean Model (POM), was validated by long-term observations of sea level, salinity and water temperature fluctuations. The modelled sea surface temperature (SST) fields were also compared to satellite images - satisfactory correlation coefficients were obtained. The model bias and efficiency coefficients of the modelled variables in relation to the observed values were determined. The quality of model simulations in relation to measured values was estimated with respect to spatial and seasonal variability in shallow and deep coastal waters as well as in the open sea. The results indicated the high quality of simulations by the hydrodynamic model.
full, complete article (PDF - compatibile with Acrobat 3.0), 690 KB

 Ecohydrodynamic model of the Baltic Sea. Part 2. Validation of the model
Oceanologia 2005, 47(4), 543-566

Jan Jędrasik, Maria Szymelfenig
Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: janj@sat.ocean.univ.gda.pl

Keywords: Baltic Sea, ecohydrodynamic model, validation, nutrients

Received 21 February 2005, revised 26 September 2005, accepted 28 September 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
The ecohydrodynamic model for the Baltic Sea consists of two interacting parts: one describes the hydrodynamics of the water (3HD), the other organic matter production and destruction (ProDeMo). The results of the simulation were validated. The modelled processes were compared with direct observations, which demonstrated the recurrence of cycles, from the spring diatom blooms through the summer depletion of nutrient salts and algal blooms, to autumn blooms of diatoms and the subsequent destruction of organic matter, and intensified mineralisation of detritus in winter. Calibration yielded a set of coefficients complementing the algorithm of equations describing the production and destruction of organic matter in the coastal zone. Verification of the model has demonstrated that in multi-year simulations it is stable and also that it follows the laws of conservation of mass and energy. The third procedural stage of the model investigation was validation, in which statistical measures in the form of bias, correlation coefficients and effectiveness between simulations and observations not used in calibration describe the quality of ecohydrodynamic modelling in southern Baltic Sea waters.
full, complete article (PDF - compatibile with Acrobat 3.0), 581 KB

 The influence of the Hel upwelling (Baltic Sea) on nutrient concentrations and primary production - the results of an ecohydrodynamic model
Oceanologia 2005, 47(4), 567-590

Marek Kowalewski
Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland;
e-mail: ocemk@univ.gda.pl

Keywords: Baltic Sea, upwelling, ecohydrodynamic modelling, nutrients, primary production

Received 21 February 2005, revised 10 October 2005, accepted 20 October 2005.

This research was supported by the State Committee for Scientific Research, Poland (grant No 6 P04G 061 17). Editing assistance of the article was provided by BALTDER (EVK3-CT-2002-80005), funded by the European Commission under the 5th Framework Programme.
Abstract
An ecohydrodynamic model was used to investigate the effect of the Hel upwelling on nutrient concentrations, primary production and phytoplankton biomass. The model covered the whole Baltic Sea with a 5 NM grid spacing and the Gulf of Gdańsk with a 1 NM grid spacing. Validation indicated good agreement between model results and measurements in the Gdańsk Deep, and slightly weaker concord for the Hel upwelling area. The vertical nutrient fluxes associated with up- and downwelling in the Hel region were simulated for two 30-day periods in 2000. The nutrient input resulting from long-term upwelling is comparable to the load carried into the Gulf of Gdańsk by the Vistula (Wisła), the largest river in the vicinity. Performed at times when upwelling was almost permanent, the simulations showed elevated nutrient concentrations in surface waters. This was especially distinct in spring when primary production and phytoplankton biomass were both higher. In late summer, however, upwelling caused primary production to decrease, despite the elevated nutrient levels.
full, complete article (PDF - compatibile with Acrobat 3.0), 568 KB

 Modelling the seasonal dynamics of marine plankton in the southern Baltic Sea. Part 1. A Coupled Ecosystem Model
Oceanologia 2005, 47(4), 591-619

Lidia Dzierzbicka-Głowacka
Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
e-mail: dzierzb@iopan.gda.pl

Keywords: ecosystem model, nutrients, phytoplankton, microzooplankton, Pseudocalanus elongatus, Clupea harengus

Received 6 October 2005, revised 25 November 2005, accepted 1 December 2005.

This research was carried out as part of the statutory programme of the Institute of Oceanology in Sopot, Poland (No II.1.4) and was supported by the Polish State Committee of Scientific Research (grant No 2PO4F 075 27, 2004-2006).
Abstract
The paper presents a one-dimensional Coupled Ecosystem Model (1DCEM) consisting of three submodels: a meteorological submodel for the physics of the upper layer and a biological submodel, which is also driven by output from the physical submodel. The biological submodel with a high-resolution zooplankton module and a simple prey-predator module consists of seven mass conservation equations. There are six partial second-order differential equations of the diffusion type for phytoplankton, microzooplankton, mesozooplankton, fish, and two nutrient components (total inorganic nitrogen and phosphate). The seventh equation, an ordinary differential equation, describes the development of detritus at the bottom. In this model the mesozooplankton (herbivorous copepods) is represented by only one species - Pseudocalanus elongatus - and is composed of 6 cohorts. The fish predator is represented by 3 cohorts of early juvenile herring Clupea harengus. Hence, the biological submodel consists of an additional twelve equations, six for weights and six for the numbers in 6 cohorts of P. elongatus, and three equations for the biomasses of 3 predator cohorts. This model is an effective tool for solving the problem of ecosystem bioproductivity and was tested in Part 2 for one partcular year.
full, complete article (PDF - compatibile with Acrobat 3.0), 276 KB

 Modelling the light absorption properties of particulate matter forming organic particles suspended in seawater. Part 2. Modelling results
Oceanologia 2005, 47(4), 621-662

Bogdan Woźniak1,2,*, Sławomir B. Woźniak1,3, Katarzyna Tyszka1, Mirosława Ostrowska1, Roman Majchrowski2, Dariusz Ficek2, Jerzy Dera1
1Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
e-mail: wozniak@iopan.gda.pl
*corresponding author
2Institute of Physics, Pomeranian Pedagogical Academy in Słupsk,
Arciszewskiego 22 B, PL-76-200 Słupsk, Poland
3 Marine Physical Laboratory, Scripps Institution of Oceanography,
University of California at San Diego, La Jolla, 92093-0238 California, USA

Keywords: organic particles, suspended particulate matter, light absorption coefficient, imaginary part of the complex refractive index of light

Received 27 October 2005, revised 28 November 2005, accepted 1 December 2005.

This work was carried out within the framework of IO PAS's statutory research, and also as part of project PZB-KBN 056/P04/2001/3 of the Institute of Physics, Pomeranian Pedagogical Academy in Słupsk.
Abstract
Model spectra of mass-specific absorption coefficients a*OM(λ) were established for 26 naturally occurring organic substances or their possible mixtures, capable of forming particulate organic matter (POM) in the sea. An algorithm was constructed, and the set of spectra of a*OM(λ) was used to determine the spectra of the imaginary part of the complex refractive index n'p(λ) characteristic of different physical types and chemical classes of POM commonly occurring in sea water. The variability in the spectra and absolute values of n'p for the various model classes and types of POM was shown to range over many orders of magnitude. This implies that modelling the optical properties of sea water requires a multi-component approach that takes account of the numerous living and non-living fractions of POM, each of which has a different value of n'p.
full, complete article (PDF - compatibile with Acrobat 3.0), 475 KB

 Sedimentary deposition and reflux of phosphorus (P) in the Eastern Gotland Basin and their coupling with P concentrations in the water column
Oceanologia 2005, 47(4), 663-679

Sven Hille, Günther Nausch, Thomas Leipe
Leibniz Institute for Baltic Sea Research Warnemünde (IOW),
Seestrasse 15, D-18119 Warnemünde, Germany;
e-mail: sven.hille@io-warnemuende.de

Keywords: Baltic Sea, Gotland Basin, sediment, posphorus, deposition, reflux

Received 31 May 2005, revised 27 September 2005, accepted 3 October 2005.

This publication is basically a condensed version of doctoral research by the first author supported by the Leibniz Institute for Baltic Sea Research, Warnemünde.
Abstract
In order to describe the role of sedimentary processes for the phosphorus (P) cycle in the open Baltic Proper, P deposition and reflux were quantified for the predominately anoxic sediments of the Eastern Gotland Basin. The study is based on investigations of 53 surface sediment samples and pore water samples from 8 sediment cores. The average P deposition rate was estimated at 0.20 g ± 0.18 g -2 yr-1, the fluctuation being due to variable bulk sediment deposition rates. P refluxes were estimated by applying Fick's First Law of Diffusion. A fairly good positive correlation between sedimentary P deposition and P release was obtained. P release from sediments by diffusion exceeds net P deposition by a factor of 2. This suggests that 2/3 of the deposited gross P is recycled in the sediments and released back into the water column; only 1/3 remains in the sediment permanently. A budget calculation demonstrates that the released dissolved inorganic phosphorus (DIP) accounts for the observed increase in DIP concentrations in the deep water during periods of stagnation, which is noticeable even at the surface P concentrations. Under such conditions and with the present remediation conditions it is not possible to freely manage P concentrations in the water column on short time scales.
full, complete article (PDF - compatibile with Acrobat 3.0), 247 KB