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Wyszukujesz frazę "Woźniak, S." wg kryterium: Autor


Wyświetlanie 1-6 z 6
Tytuł:
Inherent optical properties of suspended particulate matter in the Southern Baltic Sea
Autorzy:
Wozniak, S.B.
Meller, J.
Lednicka, B.
Zdun, A.
Ston-Egiert, J.
Powiązania:
https://bibliotekanauki.pl/articles/48001.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic Sea
chlorophyll a
coastal water
Gdansk Gulf
inherent optical property
light absorption
optical property
particulate organic carbon
particulate organic matter
phytoplankton
scattering
surface water
suspended particulate matter
Opis:
The inherent optical properties (IOPs) of suspended particulate matter and their relations with the main biogeochemical characteristics of particles have been examined in the surface waters of the southern Baltic Sea. The empirical data were gathered at over 300 stations in open Baltic Sea waters as well as in the coastal waters of the Gulf of Gdańsk. The measurements included IOPs such as the absorption coefficient of particles, absorption coefficient of phytoplankton, scattering and backscattering coefficients of particles, as well as biogeochemical characteristics of suspended matter such as concentrations of suspended particulate matter (SPM), particulate organic matter (POM), particulate organic carbon (POC) and chlorophyll a (Chl a). Our data documented the very extensive variability in the study area of particle concentration measures and IOPs (up to two orders of magnitude). Although most of the particle populations encoun- tered were composed primarily of organic matter (av. POM/SPM=ca 0.8), the different particle concentration ratios suggest that the particle composition varied significantly. The relations between the optical properties and biogeochemical parameters of suspended matter were examined. We found significant variability in the constituent-specific IOPs (coefficients of variation (CVs) of at least 30% to 40%, usually more than 50%). Simple best-fit relations between any given IOP versus any constituent concentration parameter also highlighted the significant statistical errors involved. As a result, we conclude that for southern Baltic samples an easy yet precise quantification of particle IOPs in terms of the concentration of only one of the following parameters – SPM, POM, POC or Chl a – is not achievable. Nevertheless, we present a set of best statistical formulas for a rough estimate of certain seawater constituent concentrations based on relatively easily measurable values of seawater IOPs. These equations can be implemented in practice, but their application will inevitably entail effective statistical errors of estimation of the order of 50% or more.
Źródło:
Oceanologia; 2011, 53, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Jakosc wody w zbiornikach o roznym nasileniu antropopresji a strategie zyciowe glonow planktonowych
Autorzy:
Ligeza, S
Wilk-Wozniak, E.
Powiązania:
https://bibliotekanauki.pl/articles/806555.pdf
Data publikacji:
2006
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
antropopresja bezposrednia
fitoplankton
zbiorniki wodne
glony
wlasciwosci fizykochemiczne
woda
jakosc wody
anthropopression
phytoplankton
water reservoir
alga
physicochemical property
water
water quality
Opis:
W 3 zbiornikach o różnej jakości wody i natężeniu antropopresji badano właściwości fizyczno-chemiczne wody. Przeanalizowano strategie życiowe grup glonów planktonowych i na tej podstawie dokonano oceny przydatności fitoplanktonu do określenia jakości wody. W zbiornikach płytkich, polimiktycznych, z dużą dostępnością związków pokarmowych, dominowały gatunki strategii typu C (competitors - gatunki współzawodniczące o dostępność no. pokarmu, światła), R (ruderals - gatunki „wszędobylskie”), C/R (gatunki o strategii mieszanej C/R). W zbiorniku głębokim, dimiktycznym, w którym występują okresowe braki dostępności pokarmu, stwierdzono obecność wśród dominantów, gatunków zaliczanych do grup S (stress tolerators - gatunki tolerujące warunki stresowe, np. okresowe braki dostępności pokarmu), R, C/S (gatunki o strategii mieszanej (C/S), C/R i tylko w okresie wiosny gatunków z grupy C.
Physico-chemical properties of water from 3 reservoirs with different levels of anthropopresure and water quality were investigated. Life strategies of plank- tic algae stated in the studied water bodies were analyzed to evaluate the usefulness of algae for water quality assessment. Individuals representing strategies of type C (competitors), R (ruderals), C/R dominated in the shallow and polimictic reservoirs with high levels of nutrients. Species which belonged to S (stress tolerators), R, C/S, and C/R groups dominated in the deep and dimictic reservoirs where seasonal deficits of nutrients could occur sporadically. In addition, individuals from C strategy were present there only in the spring.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 2006, 515; 251-259
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling light and photosynthesis in the marine environment
Autorzy:
Wozniak, B.
Dera, J.
Ficek, D.
Majchrowski, R.
Ostrowska, M.
Kaczmarek, S.
Powiązania:
https://bibliotekanauki.pl/articles/47660.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
primary production
pigment
underwater irradiance
marine environment
quantum yield
remote sensing algorithm
bio-optical modelling
photoacclimation
phytoplankton
chromatic acclimation
light absorption
photosynthesis
Opis:
The overriding and far-reaching aim of our work has been to achieve a good understanding of the processes of light interaction with phytoplankton in the sea and to develop an innovative physical model of photosynthesis in the marine environment,suita ble for the remote sensing of marine primary production. Unlike previous models,the present one takes greater account of the complexity of the physiological processes in phytoplankton. We have focused in particular on photophysiological processes,whic h are governed directly or indirectly by light energy,or in which light, besides the nutrient content in and the temperature of seawater,is one of the principal limiting factors. To achieve this aim we have carried out comprehensive statistical analyses of the natural variability of the main photophysiological properties of phytoplankton and their links with the principal abiotic factors in the sea. These analyses have made use of extensive empirical data gathered in a wide diversity of seas and oceans by Polish and Russian teams as well as by joint Polish-Russian expeditions. Data sets available on the Internet have also been applied. As a result,a set of more or less complex,semi-empir ical models of light-stimulated processes occurring in marine phytoplankton cells has been developed. The trophic type of sea, photo-acclimation and the production of photoprotecting carotenoids,c hromatic acclimation and the production of various forms of chlorophyll-antennas and photosynthetic carotenoids,cell adaptation by the package effect, light absorption, photosynthesis, photoinhibition,the fluorescence effect,a nd the activation of PS2 centres are all considered in the models. These take into account not only the influence of light,but also, indirectly,tha t of the vertical mixing of water; in the case of photosynthesis,the quantum yield has been also formulated as being dependent on the nutrient concentrations and the temperature of seawater. The bio-optical spectral models of irradiance transmittance in case 1 oceanic waters and case 2 Baltic waters,dev eloped earlier,a lso are described in this paper. The development of the models presented here is not yet complete and they all need continual improvement. Nevertheless,w e have used them on a preliminary basis for calculating various photosynthetic characteristics at different depths in the sea,su ch as the concentration of chlorophyll and other pigments, and primary production. The practical algorithm we have constructed allows the vertical distribution of these characteristics to be determined from three input data: chlorophyll a concentration,irradiance, and temperature at the sea surface. Since all three data can be measured remotely,ou r algorithm can be applied as the ‘marine part’ of the remote sensing algorithms used for detecting marine photosynthesis.
Źródło:
Oceanologia; 2003, 45, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of the in vivo spectral absorption of algal pigments. Part 1. Mathematical apparatus
Autorzy:
Wozniak, B.
Dera, J.
Ficek, D.
Majchrowski, R.
Kaczmarek, S.
Ostrowska, M.
Koblentz-Mishke, O.I.
Powiązania:
https://bibliotekanauki.pl/articles/48333.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
chlorophyll a
bio-optical modelling
photosynthetic pigment
photoacclimation
sea water
algal pigment
in vivo
phytoplankton
mathematical apparatus
chromatic acclimation
light absorption
Opis:
Existing statistical models of in vivo light absorption by phytoplankton (Woźniak & Ostrowska 1990, Bricaud et al. 1995, 1998) describe the dependence of the phytoplankton specific spectral absorption coefficient a∗ pl(λ) on the chlorophyll a concentration Ca in seawater. However, the models do not take into account the variability in this relationship due to phytoplankton acclimation. The observed variability in the light absorption coefficient and its components due to various pigments with depth and geographical position at sea, requires further accurate modelling in order to improve satellite remote sensing algorithms and interpretation of ocean colour maps. The aim of this paper is to formulate an improved model of the phytoplankton spectral absorption capacity which takes account of the pigment composition and absorption changes resulting from photo- and chromatic acclimation processes, and the pigment package effect. It is a synthesis of earlier models and the following statistical generalisations: (1) statistical relationships between various pigment group concentrations and light field properties in the sea (described by Majchrowski & Ostrowska 2000, this volume); (2) a model of light absorption by phytoplankton capable of determining the mathematical relationships between the spectral absorption coefficients of the various photosynthetic and photoprotecting pigment groups, and their concentrations in seawater (Woźniak et al. 1999); (3) bio-optical models of light propagation in oceanic Case 1 Waters and Baltic Case 2 Waters (Woźniak et al. 1992a, b, 1995a,b). The generalised model described in this paper permits the total phytoplankton light absorption coefficient in vivo as well as its components related to the various photosynthetic and photoprotecting pigments to be determined using only the surface irradiance PAR(0+) surface chlorophyll concentration Ca(0) and depth z in the sea as input data.
Źródło:
Oceanologia; 2000, 42, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model of the in vivo spectral absorption of algal pigments. Part 2. Practical applications of the model
Autorzy:
Majchrowski, R.
Wozniak, B.
Dera, J.
Ficek, D.
Kaczmarek, S.
Ostrowska, M.
Koblentz-Mishke, O.I.
Powiązania:
https://bibliotekanauki.pl/articles/48872.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
practical application
bio-optical modelling
depth
algal pigment
in vivo
sea
statistical model
phytoplankton
light absorption
Opis:
The article describes applications and accuracy analyses of a statistical model of light absorption by phytoplankton that accounts for the influence of photo- and chromatic acclimation on its absorption properties. Part 1 of this work (seeWoźniak et al. 2000, this volume) describes the mathematical apparatus of the model. Earlier models by Woźniak & Ostrowska (1990) and by Bricaud et al. (1995, 1998) are analysed for comparison. Empirical verification of these three models shows that the new model provides a much better approximation of phytoplankton absorption properties than do the earlier models. The statistical errors in estimating the mean absorption coefficient apl, for example, are σ+ = 36% for the new model, whereas for the earlier models the figures are σ+ = 43% (Bricaud et al. 1995, 1998) and σ+ = 59% (Woźniak & Ostrowska 1990). Example applications are given of the new model illustrating the variability in phytoplankton absorption properties with depth and trophicity of the sea.
Źródło:
Oceanologia; 2000, 42, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement of phytoplankton photosynthesis rate using a pump-and-probe fluorometer
Autorzy:
Antal, T.K.
Venediktov, P.S.
Matorin, D.N.
Ostrowska, M.
Wozniak, B.
Rubin, A.B.
Powiązania:
https://bibliotekanauki.pl/articles/47511.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
phytoplankton
photosynthesis rate
photosynthesis measurement
fluorometer
plant luminescence
fluorometric method
primary production
Opis:
In this work we have studied the possibility of determining the rate of phytoplankton photosynthesis in situ using a submersible pump-and-probe fluorometer in water areas differing in their trophic level, as well as in climatic and hydrophysical characteristics. A biophysical model was used to describe the relationship between photosynthesis, underwater irradiance, and the intensity of phytoplankton fluorescence excited by an artificial light source. Fluorescence intensity was used as a measure of light absorption by phytoplankton and for assessing the efficiency of photochemical energy conversion at photosynthetic reaction centers. Parameters of the model that could not be measured experimentally were determined by calibrating fluorescence and irradiance data against the primary production measured in the Baltic Sea with the radioactive carbon method. It was shown that the standard deviation of these parameters in situ did not exceed 20%, and the use of their mean values to estimate the phytoplankton photosynthetic rate showed a good correlation between the calculated and measured data on primary production in the Baltic (r = 0.89), Norwegian (r = 0.77) and South China (r = 0.76) Seas.
Źródło:
Oceanologia; 2001, 43, 3; 291-313
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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