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Wyszukujesz frazę "Photosynthesis" wg kryterium: Temat


Wyświetlanie 1-12 z 12
Tytuł:
Quantum yield of photosynthesis in the Baltic: a new mathematical expression for remote sensing applications
Autorzy:
Wozniak, B.
Ficek, D.
Ostrowska, M.
Majchrowski, R.
Dera, J.
Powiązania:
https://bibliotekanauki.pl/articles/49078.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
remote sensing
application
phytoplankton photosynthesis
photosynthesis quantum yield
Baltic Sea
Opis:
Statistical relationships between the quantum yield of photosynthesis Φ and selected environmental factors in the Baltic have been established on the basis of a large quantity of empirical data. The model formula is the product of the theoretical maximum quantum yield ΦMAX =0.125 atomC quantum−1 and five dimensionless factors fi taking values from 0 do 1: Φ = ΦMAXfa fΔ fc(Ca(0)) fc(PARinh) fE, t. To a sufficiently good approximation, each of these factors fi appears to be dependent on one or at most two environmental factors, such as temperature, underwater irradiance, surface concentration of chlorophyll a, absorption properties of phytoplankton and optical depth. These dependences have been determined for Baltic Case 2 waters. The quantum yield Φ, calculated from known values of these environmental factors, is then applicable in the model algorithm for the remote sensing of Baltic primary production. The statistical error of the approximate quantum yields Φ is 62%.
Źródło:
Oceanologia; 2007, 49, 4
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
Tytuł:
Practical applications of the multi-component marine photosynthesis model (MCM)
Autorzy:
Ficek, D.
Majchrowski, R.
Ostrowska, M.
Kaczmarek, S.
Wozniak, B.
Dera, J.
Powiązania:
https://bibliotekanauki.pl/articles/48509.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
primary production
quantum yield
inorganic nitrogen
temperate zone
tropical zone
practical application
bio-optical modelling
marine photosynthesis model
marine alga
polar zone
photosynthesis
Opis:
This paper describes the applications and accuracy analyses of our multi-component model of marine photosynthesis, given in detail in Woźniak et al. (2003). We now describe an application of the model to determine quantities characterising the photosynthesis of marine algae, especially the quantum yield of photosynthesis and photosynthetic primary production. These calculations have permitted the analysis of the variability of these photosynthesis characteristics in a diversity of seas, at different seasons, and at different depths. Because of its structure, the model can be used as the ‘marine part’ of a ‘satellite’ algorithm for monitoring primary production in the sea (the set of input data necessary for the calculations can be determined with remote sensing methods). With this in mind, in the present work, we have tested and verified the model using empirical data. The verification yielded satisfactory results: for example, the statistical errors in estimates of primary production in the water column for Case 1 Waters do not exceed 45%. Hence, this model is far more accurate than earlier, less complex models hitherto applied in satellite algorithms.
Źródło:
Oceanologia; 2003, 45, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorithm for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 1: Mathematical apparatus
Autorzy:
Wozniak, B.
Krezel, A.
Darecki, M.
Wozniak, S.B.
Majchrowski, R.
Ostrowska, M.
Kozlowski, L.
Ficek, D.
Olszewski, J.
Dera, J.
Powiązania:
https://bibliotekanauki.pl/articles/47484.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
light-photosynthesis model
algorithm
chlorophyll
mathematical apparatus
temperature
primary production
Baltic ecosystem
remote sensing
Opis:
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).
Źródło:
Oceanologia; 2008, 50, 4; 451-508
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of non-photosynthetic pigments on the measured quantum yield of photosynthesis
Autorzy:
Ficek, D.
Majchrowski, R.
Ostrowska, M.
Wozniak, B.
Powiązania:
https://bibliotekanauki.pl/articles/47492.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine phytoplankton
pigment
quantum yield
chlorophyll a
phytoplankton pigment
bio-optical modelling
concentration
sea
water column
photosynthesis
Opis:
The aim of this work was to assess the effect of non-photosynthetic (photoprotecting) pigments on the measured quantum yield of photosynthesis in the sea. The energy absorbed by these pigments is not utilised during photosynthesis. As a result, the measured yield of this process, i.e. the photosynthetic yield referred to the total energy absorbed by all phytoplankton pigments, is less than the actual quantum yield of photosynthesis, i.e. the yield referred to the energy absorbed by photosynthetic pigments only. The model of the absorption properties of marine phytoplankton derived by the authors (see Woźniak et al. 2000, this volume) was employed to determine the relevant contributions of photosynthetic and non-photosynthetic pigments to the total energy absorbed by phytoplankton in different trophic types of seas and at different depths in the water column. On this basis the non-photosynthetic pigment absorption factor fa, which describes the relation between the true and measured quantum yields of photosynthesis, could be characterised. The analysis shows that fa varies in value from 0.33 to 1, and that it depends on the trophic type of sea and the depth in the water column. The values of this factor are usually highest in eutrophic waters and decrease as waters become progressively more oligotrophic. It is also characteristic of fa that it increases with increasing depth in the sea.
Źródło:
Oceanologia; 2000, 42, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dependence of the photosynthesis quantum yield in oceans on environmental factors
Autorzy:
Wozniak, B.
Dera, J.
Ficek, D.
Ostrowska, M.
Majchrowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/48279.pdf
Data publikacji:
2002
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
primary production
water temperature
quantum yield
environmental factor
bio-optical modelling
nutrient content
phytoplankton
chlorophyll
irradiance
photosynthesis
Opis:
Statistical relationships between the quantum yield of photosynthesis and selected environmental factors in the ocean have been studied. The underwater irradiance, nutrient content, water temperature and water trophicity (i.e. the surface concentration of chlorophyll Ca(0)) have been considered, utilizing a large empirical data base. On the basis of these relationships, a mathematical model of the quantum yield was worked out in which the quantum yield Φ is expressed as a product of the theoretical maximum quantum yield ΦMAX = 0.125 atomC quanta−1 and six dimensionless factors. Each of these factors fi appears to be, to a sufficiently good approximation, dependent on one or two environmental factors and optical depth at most. The model makes it possible to determine the quantum yield from known values of these environmental factors. Empirical verification of the model yielded a positive result – the statistical error of the approximate values of the quantum yield Φ is 42%.
Źródło:
Oceanologia; 2002, 44, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Algorithms for the remote sensing of the Baltic ecosystem (DESAMBEM). Part 2: Empirical validation
Autorzy:
Darecki, M.
Ficek, D.
Krezel, A.
Ostrowska, M.
Majchrowski, R.
Wozniak, S.B.
Bradtke, K.
Dera, J.
Wozniak, B.
Powiązania:
https://bibliotekanauki.pl/articles/47590.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
light-photosynthesis model
algorithm
chlorophyll
ocean colour
temperature
marine ecosystem
monitoring
empirical validation
primary production
Baltic ecosystem
remote sensing
Opis:
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.
Źródło:
Oceanologia; 2008, 50, 4; 509-538
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model dependences of the deactivation of phytoplankton pigment excitation energy on environmental conditions in the sea
Autorzy:
Ostrowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/48327.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
chlorophyll a
fluorescence
marine photosynthesis
non-photochemical quenching
quantum yield
deactivation process
heat production
phytoplankton pigment
excitation energy
environment condition
Źródło:
Oceanologia; 2012, 54, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variability of the portion of functional PS2 reaction centres in the light of a fluorometric study
Autorzy:
Ficek, D.
Ostrowska, M.
Kuzio, M.
Pogosyan, S.I.
Powiązania:
https://bibliotekanauki.pl/articles/48365.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
marine phytoplankton
variability
quantum yield
chlorophyll a
optical depth
PS2 reaction
environmental factor
photosynthetic apparatus
sea
fluorometric method
light
photosynthesis
Opis:
The paper contains a preliminary analysis of the links between the portion fc of functional PS2 reaction centres in the photosynthetic apparatus of marine phytoplankton and environmental factors. The analysis is based inter alia on fluorometric measurements of fc (see Kolber & Falkowski 1993) in water sampled from different depths and trophic types of sea. From the statistical generalisations was derived an analytical form of the relationship between fc, and the optical depth and trophic type of sea (the trophicity index was taken to be the surface concentration of chlorophyll a). According to this relationship, fc rises as the trophicity of the sea does so. Moreover, there is a certain optimal optical depth for each type of water at which the number of functional PS2 reaction centres reaches a maximum. Above or below this depth the value of fc falls. At the present stage of investigations it seems reasonable to assume that this drop in the number of functional PS2 reaction centres close to the surface is due to the destructive effect of excessive irradiance. On the other hand, their reduced number at greater depths, below the fc maximum, can be attributed to the deficit of light and the consequent destruction of reaction centres.
Źródło:
Oceanologia; 2000, 42, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelled quantum yields and energy efficiency of fluorescence, photosynthesis and heat production by phytoplankton in the World Ocean
Autorzy:
Ostrowska, M.
Wozniak, B.
Dera, J.
Powiązania:
https://bibliotekanauki.pl/articles/47432.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
World Ocean
chlorophyll a
fluorescence
photosynthesis
organic matter
heat production
phytoplankton
light energy
excitation energy
pigment
quantum yield
energy efficiency
photosynthetic pigment
Źródło:
Oceanologia; 2012, 54, 4
0078-3234
Pojawia się w:
Oceanologia
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:
SatBaltyk – A Baltic environmental satellite remote sensing system – an ongoing project in Poland. Part 2: Practical applicability and preliminary results
Autorzy:
Wozniak, B.
Bradtke, K.
Darecki, M.
Dera, J.
Dudzinska-Nowak, J.
Dzierzbicka-Glowacka, L.
Ficek, D.
Furmanczyk, K.
Kowalewski, M.
Krezel, A.
Majchrowski, R.
Ostrowska, M.
Paszkuta, M.
Ston-Egiert, J.
Stramska, M.
Zapadka, T.
Powiązania:
https://bibliotekanauki.pl/articles/48019.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Baltic ecosystem
Baltic Sea
energy influx
irradiance condition
marine optics
photosynthesis
plant community
Polska
practical application
preliminary result
radiation balance
remote sensing
SatBaltyk project
satellite monitoring
sea surface
solar energy
Opis:
This paper is the second part of the description of the first stage of the SatBałtyk project’s implementation. Part 1 (Woźniak et al. 2011, in this issue) presents the assumptions and objectives of SatBałtyk and describes the most important stages in the history of our research, which is the foundation of this project. It also discusses the operation and general structure of the SatBałtyk system. Part 2 addresses various aspects of the practical applicability of the SatBałtyk Operational System to Baltic ecosystem monitoring. Examples are given of the Baltic’s characteristics estimated using the preliminary versions of the algorithms in this Operational System. At the current stage of research, these algorithms apply mainly to the characteristics of the solar energy influx and the distribution of this energy among the various processes taking place in the atmosphere-sea system, and also to the radiation balance of the sea surface, the irradiance conditions for photosynthesis and the condition of plant communities in the water, sea surface temperature distributions and some other marine phenomena correlated with this temperature. Monitoring results obtained with these preliminary algorithms are exemplified in the form of distribution maps of selected abiotic parameters of the Baltic, as well as structural and functional characteristics of this ecosystem governed by these parameters in the Baltic’s many basins. The maps cover practically the whole area of the Baltic Sea. Also given are results of preliminary inspections of the accuracy of the magnitudes shown on the maps. In actual fact, the errors of these estimates are relatively small. The further practical application of this set of algorithms (to be gradually made more specific) is therefore entirely justified as the basis of the SatBałtyk system for the effective operational monitoring of the state and functioning of Baltic ecosystems. This article also outlines the plans for extending SatBałtyk to include the recording of the effects and hazards caused by current and expected storm events in the Polish coastal zone.
Źródło:
Oceanologia; 2011, 53, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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