Oceanologia No. 46 (4) / 04




Relationships between atmospheric positive electric charge densities and gas bubble concentrations in the Baltic Sea
Oceanologia 2004, 46(4), 459-476

Zygmunt Klusek1,*, Andrzej Wiszniewski2, Jaromir Jakacki3
1Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
e-mail: klusek@iopan.gda.pl
2Medical University of Gdańsk,
Dębinki 1, PL-80-211 Gdańsk, Poland
3Naval Postgraduate School,
833 Dyer Road, Monterey, CA 93943, USA
*corresponding author

Keywords: atmospheric electricity, air ions, gas bubbles, Baltic Sea

Manuscript received 6 May 2004, reviewed 27 August 2004, accepted 28 October 2004.
Simultaneous measurements of bubble density in the sea subsurface and positive ions in the lower atmosphere were performed in the Baltic Sea in the summer of 1999. Bubbles in two size ranges, around 27 and 100 µm, were measured acoustically. Airborne positive charge was measured with a Gerdien instrument. Observed concentrations of air ions varied from 60 cm-3 up to 600 cm-3.
     The relative role of bubbles and wind speed on the positive air ion concentrations over the brackish water of the Baltic Sea is discussed. The parameters of a model of a log-log dependence between charge concentration and bubble density are calculated.
     The correlation functions between time series of concentrations of positive charges over the sea and gas bubbles averaged over a depth range from 0.4 to 4 m and wind speed are presented. There was zero lag between the cross-correlation maxima of charge and bubbles, but there was a phase lag of one and a half hours between charge and wind speed.

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Shear-generating motions at various length scales and frequencies in the Baltic Sea - an attempt to narrow down the problem of horizontal dispersion
Oceanologia 2004, 46(4), 477-503

Signild Nerheim
Department of Oceanography, Gothenburg University,
Box 460, SE-405-30 Göteborg, Sweden;
e-mail: sine@oce.gu.se

Keywords: horizontal dispersion, Baltic Proper, shear-dispersion, inertial currents

Manuscript received 23 July 2004, reviewed 20 August 2004, accepted 4 September 2004.
In the Baltic Proper, the mean circulation is too weak to explain the fast southward spreading of the so-called juvenile freshwater trapped by the seasonal thermocline in the summer season. Improved knowledge of the spatial and temporal scales of the velocity field is needed to better model dispersion. Spatial and temporal scales are investigated using some large historic data sets. Inertial oscillations are almost always present in the Baltic Proper, irrespective of wind conditions and mixed layer thicknesses. Analyses of the coherence in one data set reveal that the inertial oscillations have a horizontal coherence scale of 10-20 km under the conditions experienced during those measurements. Transient eddies and basin-scale modes with weaker periodicity are also indicated in our data sets. A tentative wavenumber spectrum is constructed for the Baltic Proper.
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Modelling the bidirectional reflectance distribution functions (BRDF) of sea areas polluted by oil
Oceanologia 2004, 46(4), 505-518

Zbigniew Otremba
Gdynia Maritime University,
Morska 83, PL-81-225 Gdynia, Poland;
e-mail: zotremba@am.gdynia.pl

Keywords: reflectance, BRDF, remote sensing, radiance

Manuscript received 8 July 2004, reviewed 30 August 2004, accepted 22 September 2004.
The paper discusses the possibilities of modelling the bi-directional reflectance distribution function (BRDF) in sea areas polluted by oil. Three sea basin models are considered: a coastal one free of oil, one polluted by an oil film and one polluted by an oil emulsion. The following concentrations of oil were compared: for the film, 1 cm3 of oil per 1 m2 water surface, for the emulsion 1 cm3 of oil in 1 m3 of water. The optical properties of Romashkino crude oil were taken into consideration, as were various angles of incident solar light. The conversion of BRDFs into a directional distribution of the optical contrast of polluted areas is demonstrated.
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Chlorophyll fluorimetry as a method for studying light absorption by photosynthetic pigments in marine algae
Oceanologia 2004, 46(4), 519-531

Dmitrii N. Matorin1, Taras K. Antal1, Mirosława Ostrowska2, Andrei B. Rubin1, Dariusz Ficek3, Roman Majchrowski3
1Department of Biophysics, Faculty of Biology, Moscow State University,
Moscow, 119899 Russia;
e-mail: matorin@biophys.msu.ru
2Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
3Pomeranian Pedagogical University,
Arciszewskiego 22b, PL-76-200 Słupsk, Poland

Keywords: fluorescence, photosynthetic pigments, light absorption, phytoplankton

Manuscript received 18 June 2004, reviewed 14 October 2004, accepted 5 November 2004.

This work was carried out within the framework of IOPAN's statutory research, and also as part of project PZB-KBN 056/PO4/2001/3 of the Institute of Physics, Pomeranian Pedagogical Academy, Słupsk
Using laboratory cultures of algae and natural phytoplankton populations from Nhatrang Bay (South China Sea), the relationship between the chlorophyll fluorescence F0, the chlorophyll a concentration Ca and light absorption capacities of algae cells was studied. It is shown that the ratio F0/Ca depends mainly on the species composition of the algae population; hence, the concentration Ca can be measured with the fluorescence method with acceptable accuracy only when the species composition of algae populations varies over a rather narrow range. The fluorescence F0 can, however, be a good index of the total absorption capacities of different phytoplankton species, because the intensity of F0 depends on the sum total of light absorbed by all photosynthetic pigments in a plant cell. Thus, the fluorescence F0 measures not only the concentration of chlorophyll a, but that of all photosynthetic pigment concentrations.
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Spectra of light absorption by phytoplankton pigments in the Baltic; conclusions to be drawn from a Gaussian analysis of empirical data
Oceanologia 2004, 46(4), 533-555

Dariusz Ficek1, Sławomir Kaczmarek2, Joanna Stoń-Egiert2, Bogdan Woźniak2, Roman Majchrowski1, Jerzy Dera2
1Institute of Physics, Pomeranian Pedagogical Academy in Słupsk,
Arciszewskiego 22B, PL-76-200 Słupsk, Poland; e-mail: darek@if.pap.edu.pl
2Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland

Keywords: bio-optics, phytoplankton pigments, light absorption, case 2 waters, remote sensing algorithm, Baltic Sea

Manuscript received 20 October 2004, reviewed 16 November 2004, accepted 23 November 2004.

This work was carried out within the framework of IO PAN'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.
Analysed by differential spectroscopy, 1208 empirical spectra of light absorption apl(λ) by Baltic phytoplankton were spectrally decomposed into 26 elementary Gaussian component bands. At the same time the composition and concentrations of each of the 5 main groups of pigments (chlorophylls a, chlorophylls b, chlorophylls c, photosynthetic carotenoids and photoprotecting carotenoids) were analysed in 782 samples by HPLC. Inspection of the correlations between the intensities of the 26 elementary absorption bands and the concentrations of the pigment groups resulted in given elementary bands being attributed to particular pigment groups and the spectra of the mass-specific absorption coefficients established for these pigment groups. Moreover, balancing the absorption effects due to these 5 pigment groups against the overall absorption spectra of phytoplankton suggested the presence of a sixth group of pigments, as yet unidentified (UP), undetected by HPLC. A preliminary mathematical description of the spectral absorption properties of these UP was established. Like some forms of phycobilins, these pigments are strong absorbers in the 450-650 nm spectral region. The packaging effect of pigments in Baltic phytoplankton was analysed statistically, then correlated with the concentration of chlorophyll a in Baltic water. As a result, a Baltic version of the algorithm of light absorption by phytoplankton could be developed. This algorithm can be applied to estimate overall phytoplankton absorption spectra and their components due to the various groups of pigments from a knowledge of their concentrations in Baltic water.
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The major Baltic inflow in January 2003 and preconditioning by smaller inflows in summer/autumn 2002: a model study
Oceanologia 2004, 46(4), 557-579

H. E. Markus Meier1, Ralf Döscher1, Barry Broman1, Jan Piechura2
1Swedish Meteorological and Hydrological Institute, Rossby Centre, SE-60176 Norrköping, Sweden;
e-mail: markus.meier@smhi.se
2Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland

Keywords: Baltic Sea, numerical modeling, major Baltic inflow, climate variability, bottom boundary layer

Manuscript received 29 September 2004, reviewed 15 November 2004, accepted 23 November 2004.
Using the results of the Rossby Centre Ocean model (RCO) the Baltic inflows in summer/autumn 2002 and January 2003 have been studied. The model results were extracted from a long simulation with observed atmospheric forcing starting in May 1980. In RCO a bottom boundary layer model was embedded. Both the smaller inflows and the major inflow in January 2003 are simulated in good agreement with observations. We found that a total of 222 km3 water entered the Baltic in January; the salinity of 94 km3 was greater than 17 PSU. In August/September 2002 the outflow through the Sound and inflow across the Darss Sill were simulated. The net inflow volume amounted to about 50 km3.
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Evidence for a warm water inflow into the Baltic Proper in summer 2003
Oceanologia 2004, 46(4), 581-598

Rainer Feistel1, *, Günther Nausch1, Toralf Heene1, Jan Piechura2, Eberhard Hagen1
1Baltic Sea Research Institute,
Seestrasse 15, D-18119 Rostock-Warnemünde, Germany;
e-mail: rainer.feistel@io-warnemuende.de
*corresponding author
2Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland

Keywords: inflow, hydrography, warm water, temperature, oxygen conditions, Baltic Sea

Manuscript received 29 September 2004, reviewed 15 November 2004, accepted 24 November 2004.
The exceptional warm water inflow into the Baltic Sea in summer 2002, which preceded the major Baltic inflow of January 2003, was surprisingly repeated in modified form in summer 2003. Its warm waters even replaced the renewed, cold inflow waters in the eastern Gotland Basin and commenced another warm period in its deep layers, where the previous one had lasted from 1997 to 2003. Details of the temporal and spatial behaviour of this new baroclinic inflow are presented from various measurements carried out from the Kiel Bight up to Gotland, covering the Darss Sill, the Arkona, Bornholm, Gdańsk Basins and the Słupsk Channel, focused mainly on the time period between July 2003 and July 2004. Hypothetically, the repetition of these exceptional warm inflow events could be regarded as a possible regional indicator for global climatic change.
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