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J. W. Baretta - One of the best experts on this subject based on the ideXlab platform.
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European Regional Seas Ecosystem Model (ERSEM) II
Journal of Sea Research, 1997Co-Authors: J G Baretta-bekker, J. W. BarettaAbstract:Special issue of the Journal of Sea Research dealing with the results from the second phase of the European Regional Seas Ecosystem Model (ERSEM) project.
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the european regional seas Ecosystem Model a complex marine Ecosystem Model
Netherlands Journal of Sea Research, 1995Co-Authors: J. W. Baretta, W Ebenhoh, P. RuardijAbstract:Abstract This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM). The Model dynamically simulates the biogeochemical seasonal cycling of carbon, nitrogen, phosphorus and silicon in the pelagic and benthic food webs of the North Sea, and is forced by irradiance, temperature and transport processes. The Model has a coarse spatial resolution into ten boxes, the ICES boxes, of which the five deepest have been resolved into surface (0 to 30 m) and deep (30 m to bottom) boxes. At the open boundaries, time series are prescribed for dissolved and particulate nutrients. River loads of nutrients for the rivers discharging into the North Sea are prescribed at monthly intervals. A general circulation Model has been used to aggregate the exchange volumes across the box boundaries into daily in- and outflows. From these, the horizontal transports of dissolved and suspended constituents are calculated. Vertical transport is in the form of sinking and sedimentation for particulates and in the form of turbulent diffusion for dissolved constituents. The physical Model contains all information specific to the area to be Modelled, whereas the biological/chemical subModels have been constructed not to be site-specific. The biological variables are represented as functional groups expressed in units of organic carbon and the chemical variables as the internal pools in the biological variables and as the dissolved inorganic pools in water and sediment, expressed in units of N, P and Si. The Model runs in a software environment (SESAME) developed for enabling the development of large and complex Models in a modular way by a consortium of institutes, each focusing on different. aspects of the Ecosystem, translating these into modules within the Model. With the exception of fish populations, where size- and age-structure are explicity represented, all the other biological components have been Modelled as unstructured populations aggregated into functional groups. This approach is shown to be appropriate for taxa having short generation times in relation to the annual cycle and for taxa which do not span more than one trophic level during their lifetime.
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The european regional seas Ecosystem Model, a complex marine Ecosystem Model
Netherlands Journal of Sea Research, 1995Co-Authors: J. W. Baretta, W Ebenhoh, P. RuardijAbstract:Mathematics may be compared to a mill of exquisite workmanship which grinds you stuff of any degree of fineness; but, nevertheless what you get out depends upon what you put in; and as the grandest mill in the worm will not extract wheat flour from peascod, so pages of formulae will not get a definite result out of loose data. T.H. Huxley, 1897, quoted in J.E. Schindler, 1988. ABSTRACT This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM). The Model dynamically simulates the biogeochemical sea-sonal cycling of carbon, nitrogen, phosphorus and silicon in the pelagic and benthic food webs of the North Sea, and is forced by irradiance, temperature and transport processes. The Model has a coarse spatial resolution into ten boxes, the ICES boxes, of which the five deepest have been resolved into surface (0 to 30 m) and deep (30 m to bottom) boxes. At the open boundaries, time series are prescribed for dissolved and particulate nutrients. River loads of nutrients for the rivers discharging into the North Sea are prescribed at monthly intervals. A general circulation Model has been used to aggregate the exchange volumes across the box bounda-ries into daily in-and outflows. From these, the horizontal transports of dissolved and suspended con-stituents are calculated. Vertical transport is in the form of sinking and sedimentation for particulates and in the form of turbulent diffusion for dissolved constituents. The physical Model contains all information specific to the area to be Modelled, whereas the biolog-ical/chemical subModels have been constructed not to be site-specific. The biological variables are represented as functional groups expressed in units of organic carbon and the chemical variables as the internal pools in the biological variables and as the dissolved inor-ganic pools in water and sediment, expressed in units of N, P and Si. The Model runs in a software environment (SESAME) developed for enabling the development of large and complex Models in a modular way by a consortium of institutes, each focusing on different aspects of the Ecosystem, translating these into modules within the Model. With the exception of fish populations, where size-and age-structure are explicitly represented, all the other biological compo-nents have been Modelled as unstructured populations aggregated into functional groups. This approach is shown to be appropriate for taxa having short generation times in relation to the annual cycle and for taxa which do not span more than one trophic level during their lifetime.
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The European Regional Seas Ecosystem Model (ERSEM), a complex marine Ecosystem Model
Netherlands Journal of Sea Research, 1995Co-Authors: J. W. Baretta, W Ebenhoh, P. RuardijAbstract:This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM).
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The microbial food-web in the european-regional-seas-Ecosystem- Model
Netherlands Journal Of Sea Research, 1995Co-Authors: J G Barettabekker, J. W. Baretta, E K RasmussenAbstract:In the framework of the complex dynamical European Regional Seas Ecosystem Model (ERSEM) a module describing the microbial part of the pelagic Ecosystem has been developed. The module contains the carbon and nutrient dynamics of pelagic bacteria, heterotrophic flagellates and microzooplankton and interacts with the other parts of the Model via phytoplankton, particulate and dissolved organic matter and mesozooplankton. A short description of the module is given and the results are discussed. It is demonstrated that in an application of ERSEM to the North Sea there is a gradual shift in dominance from the continental coast boxes to the offshore deeper areas between the different food webs, from what in the literature is termed the classical food web to the microbial food web, concomitant with a gradual decrease in the efficiency of the microbial loop.
M E Baird - One of the best experts on this subject based on the ideXlab platform.
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Limits to prediction in a size-resolved pelagic Ecosystem Model
Journal of Plankton Research, 2010Co-Authors: M E BairdAbstract:A size-resolved pelagic Ecosystem Model has been developed based on a continuous (with size) set of Model equations and using allometric relationships to specify size-dependent physiological rates. Numerical experiments with identical Model equations but different initial conditions and size-class distributions are used to investigate inherent limits to prediction of instantaneous state from an initial condition. The simulations have relatively constant physical forcings, such as solar radiation, to emphasize the dynamical properties of the size-resolved Model. Initial condition experiments show that perturbations of 1, 0.1, 0.01, 0.001 and 0.0001% of the initial biomass of individual size-classes from a Hat size spectrum lead to equal spread of Model trajectories. The greatest divergence of trajectories occurs when a 2.7 mu m equivalent spherical radius phytoplankton size-class blooms. This divergence has a finite-time Lyapunov exponent of 0.21 day(-1) a prediction time of 33 days for a precision of 10(-3) mol N m(-3). Large member ensembles can approximately halve the effect of growth of initial condition perturbations on prediction. Further numerical experiments are undertaken with the mean body weight at which size-classes are solved perturbed randomly with a standard deviation of 0.15, 0.015, 0.0015 and 0.00015 of the unperturbed body weight. The greatest effect, which dominates the sigma = 0.15 and 0.015 ensembles, occurs when the perturbations of the size-class distribution add and/or remove predator-prey links. These results provide a cautionary warning for the prediction of instantaneous states using complex pelagic Ecosystems that are displaced from a stable oscillation and for which biological state is not dominated by physical processes.
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A size-resolved pelagic Ecosystem Model
Ecological Modelling, 2007Co-Authors: M E Baird, Iain M. SuthersAbstract:A size-resolved pelagic Ecosystem Model is developed using descriptions\nof physical limits to biological processes and allometric relationships\nto determine physiological rates. The Model contains three functional\ngroups: phytoplankton, protozoans and metazoans–requiring three\nseparately resolved size distributions. Within each functional group\nthe size-resolution of the Model can be altered without changing\nthe Model parameters, which are the coefficients of the allometric\nrelationships, or changing the Model equations, which are characteristic\nof each functional group. This approach allows the number of size-classes\nto be varied, and for a convergence of output with increasing resolution\nto be achieved. In this paper, a biological configuration is analysed\ncomposed of 62 size-classes doubling in biomass between classes and\nranging in volume over 19 orders of magnitude from 0.32[thin space]\nm3, representative of the cyanobacteria Prochlorococcus sp., to 2.05x1018\n[thin space] m3, representative of a metazoan size-class with an\nequivalent spherical radius of 78.8[thin space]cm. The phytoplankton\nsize-classes extend through the first 17 size-classes, protozoan\nfrom the 9th to 21st, and metazoan from the 18th to 62nd. The size-resolved\nModel is coupled to a 1D Model of the oceanic mixed layer. Numerical\nexperiments show the size-resolved Model is relatively insensitive\nto size resolution and higher order closure terms with the 62 size-class\nconfiguration, but is sensitive to initial conditions. The Model\noutput is most sensitive to the parameter describing the smallest\nsize-class of prey available to a metazoan predator, and the nitrogen\ncontent of a phytoplankton cell. The concentration of DIN and biomass\nof protozoa are in general the most sensitive Model outputs. These\nexperiments provide a background understanding for further application\nof the size-resolved pelagic Ecosystem Model.
Iain M. Suthers - One of the best experts on this subject based on the ideXlab platform.
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A size-resolved pelagic Ecosystem Model
Ecological Modelling, 2007Co-Authors: M E Baird, Iain M. SuthersAbstract:A size-resolved pelagic Ecosystem Model is developed using descriptions\nof physical limits to biological processes and allometric relationships\nto determine physiological rates. The Model contains three functional\ngroups: phytoplankton, protozoans and metazoans–requiring three\nseparately resolved size distributions. Within each functional group\nthe size-resolution of the Model can be altered without changing\nthe Model parameters, which are the coefficients of the allometric\nrelationships, or changing the Model equations, which are characteristic\nof each functional group. This approach allows the number of size-classes\nto be varied, and for a convergence of output with increasing resolution\nto be achieved. In this paper, a biological configuration is analysed\ncomposed of 62 size-classes doubling in biomass between classes and\nranging in volume over 19 orders of magnitude from 0.32[thin space]\nm3, representative of the cyanobacteria Prochlorococcus sp., to 2.05x1018\n[thin space] m3, representative of a metazoan size-class with an\nequivalent spherical radius of 78.8[thin space]cm. The phytoplankton\nsize-classes extend through the first 17 size-classes, protozoan\nfrom the 9th to 21st, and metazoan from the 18th to 62nd. The size-resolved\nModel is coupled to a 1D Model of the oceanic mixed layer. Numerical\nexperiments show the size-resolved Model is relatively insensitive\nto size resolution and higher order closure terms with the 62 size-class\nconfiguration, but is sensitive to initial conditions. The Model\noutput is most sensitive to the parameter describing the smallest\nsize-class of prey available to a metazoan predator, and the nitrogen\ncontent of a phytoplankton cell. The concentration of DIN and biomass\nof protozoa are in general the most sensitive Model outputs. These\nexperiments provide a background understanding for further application\nof the size-resolved pelagic Ecosystem Model.
J G Baretta-bekker - One of the best experts on this subject based on the ideXlab platform.
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European Regional Seas Ecosystem Model (ERSEM) II
Journal of Sea Research, 1997Co-Authors: J G Baretta-bekker, J. W. BarettaAbstract:Special issue of the Journal of Sea Research dealing with the results from the second phase of the European Regional Seas Ecosystem Model (ERSEM) project.
P. Ruardij - One of the best experts on this subject based on the ideXlab platform.
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Biogeochemical 1D ERSEM Ecosystem Model applied to recent carbon dioxide and nutrient data in the north sea
Developments in Environmental Modelling, 2012Co-Authors: Khalid Elkalay, P. Ruardij, Karima Khalil, Yann Bozec, Helmuth Thomas, Hein De BaarAbstract:The European Regional Seas Ecosystem Model (ERSEM) coupled to the Princeton Ocean Model (POM) one-dimensional physical Model was applied to the first results of the pluridisciplinary biogeochemical data set acquired in the North Sea during four cruises carried out from 2000 to 2001. We introduced a CO2 subModel in ERSEM and we focused on simulations at two stations, one in the southern part and one in the northern part of the North Sea. A basic validation of the simulations is presented which indicates that results are in a good agreement with the field measurements. The Model reproduces the vertical structure and the temporal variations of biogeochemical variables, both qualitatively and quantitatively. An inorganic carbon limitation function of phytoplankton growth was also implemented in the Model to investigate potential changes of Ecosystem structure with predicted future increases of atmospheric CO2 levels. A sensitivity analysis suggests that diatoms and large phytoplankton are more sensitive than flagellates and picophytoplankton to predicted future increases of atmospheric CO2 levels Biogeochemical 1D ERSEM Ecosystem Model Applied to Recent Carbon Dioxide and Nutrient Data in the North Sea. Available from: https://www.researchgate.net/publication/287322077_Biogeochemical_1D_ERSEM_Ecosystem_Model_Applied_to_Recent_Carbon_Dioxide_and_Nutrient_Data_in_the_North_Sea [accessed Aug 5, 2017].
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the european regional seas Ecosystem Model a complex marine Ecosystem Model
Netherlands Journal of Sea Research, 1995Co-Authors: J. W. Baretta, W Ebenhoh, P. RuardijAbstract:Abstract This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM). The Model dynamically simulates the biogeochemical seasonal cycling of carbon, nitrogen, phosphorus and silicon in the pelagic and benthic food webs of the North Sea, and is forced by irradiance, temperature and transport processes. The Model has a coarse spatial resolution into ten boxes, the ICES boxes, of which the five deepest have been resolved into surface (0 to 30 m) and deep (30 m to bottom) boxes. At the open boundaries, time series are prescribed for dissolved and particulate nutrients. River loads of nutrients for the rivers discharging into the North Sea are prescribed at monthly intervals. A general circulation Model has been used to aggregate the exchange volumes across the box boundaries into daily in- and outflows. From these, the horizontal transports of dissolved and suspended constituents are calculated. Vertical transport is in the form of sinking and sedimentation for particulates and in the form of turbulent diffusion for dissolved constituents. The physical Model contains all information specific to the area to be Modelled, whereas the biological/chemical subModels have been constructed not to be site-specific. The biological variables are represented as functional groups expressed in units of organic carbon and the chemical variables as the internal pools in the biological variables and as the dissolved inorganic pools in water and sediment, expressed in units of N, P and Si. The Model runs in a software environment (SESAME) developed for enabling the development of large and complex Models in a modular way by a consortium of institutes, each focusing on different. aspects of the Ecosystem, translating these into modules within the Model. With the exception of fish populations, where size- and age-structure are explicity represented, all the other biological components have been Modelled as unstructured populations aggregated into functional groups. This approach is shown to be appropriate for taxa having short generation times in relation to the annual cycle and for taxa which do not span more than one trophic level during their lifetime.
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The european regional seas Ecosystem Model, a complex marine Ecosystem Model
Netherlands Journal of Sea Research, 1995Co-Authors: J. W. Baretta, W Ebenhoh, P. RuardijAbstract:Mathematics may be compared to a mill of exquisite workmanship which grinds you stuff of any degree of fineness; but, nevertheless what you get out depends upon what you put in; and as the grandest mill in the worm will not extract wheat flour from peascod, so pages of formulae will not get a definite result out of loose data. T.H. Huxley, 1897, quoted in J.E. Schindler, 1988. ABSTRACT This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM). The Model dynamically simulates the biogeochemical sea-sonal cycling of carbon, nitrogen, phosphorus and silicon in the pelagic and benthic food webs of the North Sea, and is forced by irradiance, temperature and transport processes. The Model has a coarse spatial resolution into ten boxes, the ICES boxes, of which the five deepest have been resolved into surface (0 to 30 m) and deep (30 m to bottom) boxes. At the open boundaries, time series are prescribed for dissolved and particulate nutrients. River loads of nutrients for the rivers discharging into the North Sea are prescribed at monthly intervals. A general circulation Model has been used to aggregate the exchange volumes across the box bounda-ries into daily in-and outflows. From these, the horizontal transports of dissolved and suspended con-stituents are calculated. Vertical transport is in the form of sinking and sedimentation for particulates and in the form of turbulent diffusion for dissolved constituents. The physical Model contains all information specific to the area to be Modelled, whereas the biolog-ical/chemical subModels have been constructed not to be site-specific. The biological variables are represented as functional groups expressed in units of organic carbon and the chemical variables as the internal pools in the biological variables and as the dissolved inor-ganic pools in water and sediment, expressed in units of N, P and Si. The Model runs in a software environment (SESAME) developed for enabling the development of large and complex Models in a modular way by a consortium of institutes, each focusing on different aspects of the Ecosystem, translating these into modules within the Model. With the exception of fish populations, where size-and age-structure are explicitly represented, all the other biological compo-nents have been Modelled as unstructured populations aggregated into functional groups. This approach is shown to be appropriate for taxa having short generation times in relation to the annual cycle and for taxa which do not span more than one trophic level during their lifetime.
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The European Regional Seas Ecosystem Model (ERSEM), a complex marine Ecosystem Model
Netherlands Journal of Sea Research, 1995Co-Authors: J. W. Baretta, W Ebenhoh, P. RuardijAbstract:This paper presents an overview of the concept, structure and implementation of the European Regional Seas Ecosystem Model (ERSEM).
