Oceanologia No. 50 (4) / 08

Contents

Papers

Papers


Algorithm for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 1: Mathematical apparatus:
Oceanologia 2008, 50(4), 451-508

Bogdan Woźniak1,3,*, Adam Krężel2, Mirosław Darecki1, Sławomir B. Woźniak1, Roman Majchrowski3, Mirosława Ostrowska1, Łukasz Kozłowski2, Dariusz Ficek3, Jerzy Olszewski1, 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 Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland
3Institute of Physics, Pomeranian Academy,
Arciszewskiego 22B, PL-76-200 Słupsk, Poland

Keywords: remote sensing, marine ecosystem monitoring, chlorophyll algorithm, temperature algorithm, primary production algorithm, light-photosynthesis model

Received 29 April 2008, revised 9 September 2008, accepted 16 October 2008.

This paper was produced within the framework of the project commissioned by the Polish Committee for Scientific Research - DEvelopment of a SAtellite Method for Baltic Ecosystem Monitoring - DESAMBEM (project No. PBZ-KBN 056/P04/2001). On completion of the project, the participating institutes (Institute of Oceanology, Polish Academy of Sciences; Institute of Oceanography, University of Gdańsk; Institute of Physics, Pomeranian Academy, Słupsk) signed an agreement to set up a scientific network known as the Inter-Institute Group for Satellite Observations of the Marine Environment (Międzyinstytutowy Zespół Satelitarnych Obserwacji środowiska Morskiego), the aim of which is to undertake further work in this field of research.
Abstract
This article is the first of two papers on the remote sensing methods of monitoring the Baltic ecosystem, developed by our team. Earlier, we had produced a series of detailed mathematical models and statistical regularities describing the transport of solar radiation in the atmosphere-sea system, the absorption of this radiation in the water and its utilisation in a variety of processes, most importantly in the photosynthesis occurring in phytoplankton cells, as a source of energy for the functioning of marine ecosystems. The comprehensive DESAMBEM algorithm, presented in this paper, is a synthesis of these models and regularities. This algorithm enables the abiotic properties of the environment as well as the state and the functioning of the Baltic ecosystem to be assessed on the basis of available satellite data. It can be used to determine a good number of these properties: the sea surface temperature, the natural irradiance of the sea surface, the spectral and spatial distributions of solar radiation energy in the water, the surface concentrations and vertical distributions of chlorophyll a and other phytoplankton pigments in this sea, the radiation energy absorbed by phytoplankton, the quantum efficiency of photosynthesis and the primary production of organic matter. On the basis of these directly determined properties, other characteristics of processes taking place in the Baltic ecosystem can be estimated indirectly.
        Part 1 of this series of articles deals with the detailed mathematical apparatus of the DESAMBEM algorithm. Part 2 will discuss its practical applicability in the satellite monitoring of the sea and will provide an assessment of the accuracy of such remote sensing methods in the monitoring of the Baltic ecosystem (see Darecki et al. 2008 - this issue).
full, complete article (PDF - compatibile with Acrobat 4.0), 2.0 MB

Algorithms for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 2: Empirical validation:
Oceanologia 2008, 50(4), 509-538

Mirosław Darecki1,*, Dariusz Ficek2, Adam Krężel3, Mirosława Ostrowska1, Roman Majchrowski2, Sławomir B. Woźniak1, Katarzyna Bradtke3, Jerzy Dera1, Bogdan Woźniak1,2
1Institute of Oceanology, Polish Academy of Sciences,
Powstańców Warszawy 55, PL-81-712 Sopot, Poland;
e-mail: darecki@iopan.gda.pl
*corresponding author
2Institute of Physics, Pomeranian Academy,
Arciszewskiego 22B, PL-76-200 Słupsk, Poland
3Institute of Oceanography, University of Gdańsk,
al. Marszałka Piłsudskiego 46, PL-81-378 Gdynia, Poland

Keywords: remote sensing, marine ecosystem monitoring, chlorophyll algorithm, temperature algorithm, primary production algorithm, light-photosynthesis model, SeaWiFS, ocean colour

Received 21 July 2008, revised 7 October 2008, accepted 20 October 2008.

This paper was produced within the framework of the project commissioned by the Polish Committee for Scientific Research - DEvelopment of a SAtellite Method for Baltic Ecosystem Monitoring - DESAMBEM (project No. PBZ-KBN 056/P04/2001). On completion of the project, the participating institutes (Institute of Oceanology, Polish Academy of Sciences; Institute of Oceanography, University of Gdańsk; Institute of Physics, Pomeranian Academy, Słupsk) signed an agreement to set up a scientific network known as the Inter-Institute Group for Satellite Observations of the Marine Environment (Międzyinstytutowy Zespół Satelitarnych Obserwacji środowiska Morskiego), the aim of which is to undertake further work in this field of research.
Abstract
This paper is the second of two articles on the methodology of the remote sensing of the Baltic ecosystem. In Part 1 the authors presented the set of DESAMBEM algorithms for determining the major parameters of this ecosystem on the basis of satellite data (see Woźniak et al. 2008 - this issue). That article discussed in detail the mathematical apparatus of the algorithms. Part 2 presents the effects of the practical application of the algorithms and their validation, the latter based on satellite maps of selected Baltic ecosystem parameters: the distributions of the sea surface temperature (SST), the Photosynthetically Available Radiation (PAR) at the sea surface, the surface concentrations of chlorophyll a and the total primary production of organic matter. Particular emphasis was laid on analysing the precision of estimates of these and other parameters of the Baltic ecosystem, determined by remote sensing methods. The errors in these estimates turned out to be relatively small; hence, the set of DESAMBEM algorithms should in the future be utilised as the foundation for the effective satellite monitoring of the state and functioning of the Baltic ecosystem.
full, complete article (PDF - compatibile with Acrobat 4.0), 1.3 MB

Wave-induced stresses and pore pressures near a mudline
Oceanologia 2008, 50(4), 539-555

Andrzej Sawicki, Ryszard Staroszczyk*
Institute of Hydroengineering, Polish Academy of Sciences, (IBW PAN),
Kościerska 7, PL-80-328 Gdańsk, Poland;
e-mail: as@ibwpan.gda.pl, rstar@ibwpan.gda.pl
*corresponding author

Keywords: seabed mechanics, pore water pressures, elasto-plasticity, Coulomb-Mohr yield condition

Received 28 June 2008, revised 10 October 2008, accepted 19 November 2008.
Abstract
Conventional methods for the determination of water-wave induced stresses in seabeds composed of granular soils are based on Biot-type models, in which the soil skeleton is treated as an elastic medium. Such methods predict effective stresses in the soil that are unacceptable from the physical point of view, as they permit tensile stresses to occur near the upper surface of the seabed. Therefore, in this paper the granular soil is assumed to behave as an elastic-ideally plastic material, with the Coulomb-Mohr yield criterion adopted to bound admissible stress states in the seabed. The governing equations are solved numerically by a finite difference method. The results of simulations, carried out for the case of time-harmonic water waves, illustrate the depth distributions of the excess pore pressures and the effective stresses in the seabed, and show the shapes of zones of soil in the plastic state. In particular, the effects on the seabed behaviour of such parameters as the degree of pore water saturation, the soil permeability, and the earth pressure coefficient, are illustrated.
full, complete article (PDF - compatibile with Acrobat 4.0), 185.4 KB

Mineralogical and chemical composition of the mud fraction from the surface sediments of Sharm Al-Kharrar, a Red Sea coastal lagoon
Oceanologia 2008, 50(4), 557-575

Ali S. Basaham
Faculty of Marine Sciences, King Abdulaziz University,
PO Box 80207, Jeddah 21589, Saudi Arabia;
e-mail: abasaham@kau.edu.sa
Keywords: sediments, mud fraction, major and trace elements, coastal lagoon, Red Sea

Received 23 July 2008, revised 4 November 2008, accepted 10 November 2008.
Abstract
Interaction between continental and marine end-members gives rise to the natural biogeochemical processes in Sharm Al-Kharrar, a lagoon in the arid Red Sea region. Twenty-nine surface sediment samples were collected from the area and their mud fraction analysed for grain size, OC, CaCO3, mineralogy and elemental composition. The mud fraction consisted of a mixture of siliciclastic/calcareous materials, dominated by silt size materials and characterised by low OC (average 0.71% ±0.13); CaCO3 varied widely, with an average of 45% ±18. Concentrations of Al, Fe, Mn, Cu, Ni, Cr, V and Ba showed a wide range of variation throughout the Sharm. The results were normalised to Al and subjected to cluster analysis in order to examine the relations between the mineralogy and the elemental composition. The contents of Al, Fe, Mn, Cu, Ni, Cr, V and Ba appeared to be influenced by the mixing of the two end-members in addition to the physiochemical processes associated with the mixing between episodic freshwater flooding and seawater. Zn was the single element that showed a slight departure from the mixing model.
full, complete article (PDF - compatibile with Acrobat 4.0), 246.4 KB

Density dependent growth of the red algae Furcellaria lumbricalis and Coccotylus truncatus in the West Estonian Archipelago Sea, northern Baltic Sea
Oceanologia 2008, 50(4), 577-585

Jonne Kotta1,*, Tiina Paalme1, Priit Kersen1,2, Georg Martin1, Kristjan Herkül1,3, Tiia Möller1,3
1Estonian Marine Institute, University of Tartu,
Mäealuse 10a, EE-12618 Tallinn, Estonia;
e-mail: jonne.kotta@sea.ee
*corresponding author
2Institute of Mathematics and Natural Sciences, Tallinn University,
Narva 25, EE-10120 Tallinn, Estonia
3Institute of Ecology and Earth Sciences, University of Tartu, Vanemuise 46, EE-51014 Tartu, Estonia

Keywords: in situ experiment, red algae, density effects, growth

Received 18 January 2008, revised 24 October 2008, accepted 30 October 2008.

Funding for this research was provided by target financed project SF0180013s03 of the Estonian Ministry of Education and Reasearch and by Estonian Science Foundation grants 6015, 6016 and 6750.
Abstract
In an in situ experiment we evaluated the growth of the red algae Furcellaria lumbricalis and Coccotylus truncatus in the Archipelago Sea. The results showed that the growth rates of both species were similar but that growth decreased with increasing algal coverage. The effects were more pronounced for C. truncatus than for F. lumbricalis. Economic analyses aiming to establish sustainable harvesting limits for F. lumbricalis in the study area should take account of the density dependent growth of these red algae.
full, complete article (PDF - compatibile with Acrobat 4.0), 140.9 KB