References of "Nihoul, Jacques"
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See detailThe Aral Sea: Selected Bibliography
Nihoul, Jacques ULg; Kosarev, A.; Kostianoy, A. et al

Conference (2003, May 05)

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See detailWhat don’t we know about dying and dead seas ?
Sirjacobs, Damien ULg; Nihoul, Jacques ULg

Conference (2003, May)

As conclusions of this NATO Advanced Research Workshop on Dying and Dead Seas, numerous questions remains concerning the various studied water bodies, all along their hydrological cycle and along their ... [more ▼]

As conclusions of this NATO Advanced Research Workshop on Dying and Dead Seas, numerous questions remains concerning the various studied water bodies, all along their hydrological cycle and along their anthropic perturbations. A synthesis of most important open questions is presented. [less ▲]

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See detailGlobal water and salt budget of the Aral Sea from 1960 to 1991.
Sirjacobs, Damien ULg; Grégoire, Marilaure ULg; Delhez, Eric ULg et al

Conference (2003, May)

Focusing on the global water and salt budget of the Aral sea from 1960 till 1991, a compilation of data available in the litterature is analysed with simple models and compared to the measured evolution ... [more ▼]

Focusing on the global water and salt budget of the Aral sea from 1960 till 1991, a compilation of data available in the litterature is analysed with simple models and compared to the measured evolution of the sea. [less ▲]

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See detailInfluence of the Aral Sea negative water balance on its seasonal circulation and ventilation patterns : use of a 3D hydrodynamic model
Sirjacobs, Damien ULg; Grégoire, Marilaure ULg; Delhez, Eric ULg et al

in Geophysical Research Abstracts (2003, April), 5(09052), 2003509052

Within the context of the EU INCO-COPERNICUS program "Desertification in the Aral Sea Region: A study of the Natural and Anthropogenic Impacts" (Contract IAC2-CT-2000-10023), a large-scale 3D hydrodynamic ... [more ▼]

Within the context of the EU INCO-COPERNICUS program "Desertification in the Aral Sea Region: A study of the Natural and Anthropogenic Impacts" (Contract IAC2-CT-2000-10023), a large-scale 3D hydrodynamic model was adapted to address specifically the macroscale processes affecting the Aral Sea water circulation and ventilation. The particular goal of this research is to simulate the effect of lasting negative water balance on the 3D seasonal circulation, temperature, salinity and water-mixing fields of the Aral Sea. The original Aral Sea seasonal hydrodynamism is simulated with the average seasonal forcings corresponding to the period from 1956 to 1960. This first investigation concerns a period of relative stability of the water balance, before the beginning of the drying process. The consequences of the drying process on the hydrodynamic of the Sea will be studied by comparing this first results with the simulation representing the average situation for the years 1981 to 1985, a very low river flow period. For both simulation periods, the forcing considered are the seasonal fluctuations of wind fields, precipitation, evaporation, river discharge and salinity, cloud cover, air temperature and humidity. The meteorological forcings were adapted to the common optimum one-month temporal resolution of the available data sets. Monthly mean kinetic energy flux and surface tensions were calculated from daily ECMWF wind data. Monthly in situ precipitation, surface air temperature and humidity fields were interpolated from data obtained from the Russian Hydrological and Meteorological Institute. Monthly water discharge and average salinity of the river water were considered for both Amu Darya and Syr Darya river over each simulation periods. The water mass conservation routines allowed the simulation of a changing coastline by taking into account local drying and flooding events of particular grid points. Preliminary barotropic runs were realised (for the 1951-1960 situation, before drying up began) in order to get a first experience of the behaviour of the hydrodynamic model. These first runs provide results about the evolution of the following state variables: elevation of the sea surface, 3D fields of vertical and horizontal flows, 2D fields of average horizontal flows and finally the 3D fields of turbulent kinetic energy. The mean seasonal salinity and temperature fields (in-situ data gathered by the Russian Hydrological and Meteorological Institute) are available for the two simulated periods and will allow a first validation of the hydrodynamic model. Various satellites products were identified, collected and processed in the frame of this research project and will be used for the validation of the model outputs. Seasonal level changes measurements derived from water table change will serve for water balance validation and sea surface temperature for hydrodynamics validation. [less ▲]

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See detailExchange processes and nitrogen cycling on the shelf and slopes area of the Black Sea basin.
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Kostianoy, A. et al

Conference (2003, January)

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See detailModelling the Danube-influenced North-western continental shelf of the Black Sea. I: Hydrodynamical processes simulated by 3-D and box models
Beckers, Jean-Marie ULg; Grégoire, Marilaure ULg; Nihoul, Jacques ULg et al

in Estuarine Coastal & Shelf Science (2002), 54(3), 453-472

A hydrodynamical modelling of the Black Sea is presented using the GHER 3-D primitive equation model. Results of a very high resolution model with 5 km grid size are analysed and the dominant features of ... [more ▼]

A hydrodynamical modelling of the Black Sea is presented using the GHER 3-D primitive equation model. Results of a very high resolution model with 5 km grid size are analysed and the dominant features of general circulation in the Black Sea are highlighted. Compared with a coarse resolution model, forced with the same climatic monthly averaged atmospheric data, the high resolution model exhibits stronger variability, including frontal structures and coastal upwellings induced by baroclinic instabilities, in particular along the Turkish coast. A comparison of the shelf-open sea exchanges, with particular focus on the cold intermediate waters, shows that both models lead to a replenishment of the CIL in the basin interior by cold waters formed on the shelf. Due to the better representation of frontal structures, the high resolution model is an appropriate candidate for coupling with a biological model. Problems of calibration, interpretation and data availability typically arise from this kind of coupled 3-D model. In order to overcome such difficulties, the results of the 3-D hydrodynamical model are used to guide the development of an integrated 0-D box model capable of achieving the objectives of projects like EROS21, where the effect of changes in the Danube inflows on the shelf ecosystem is investigated. The 0-D model is thus designed to cover this region and is obtained through integration over an appropriate variable volume. The integration procedure shows where the weaknesses of an 0-D approach might lie. Diagnoses in the 3-D model of the integral quantities show the range of uncertainty one can expect in the exchange laws of the 0-D model. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailNitrogen budget on the shelf and slope area of the Back Sabasin as inferred from modeling experiments
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Friederich, J. et al

in Second International Conference on "Oceanography of the Eastern Mediterranean and Black Sea: Similarities and Differences of Two Interconnected Basins" (2002)

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See detailModelling nitrogen fluxes in a semi-enclosed environment (the Black Sea): transport versus biogeochemical processes and quantification of the exchanges at the shelf break
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Kostianoy, A. et al

in Commission internationale pour l'exportation Scientifique de la Mer Méditerranée Vol. 36 (2001)

A three-dimensional coupled biogeochemical-hydrodynamical model has been developed to get a better understanding of the biogeochemical functioning of the Black Sea. The in?uence on the ecodynamics of ... [more ▼]

A three-dimensional coupled biogeochemical-hydrodynamical model has been developed to get a better understanding of the biogeochemical functioning of the Black Sea. The in?uence on the ecodynamics of hydrodynamical and biogeochemical processes is quantified. Nitrogen inputs from the rivers, from the sediments and from the deep sea are estimated and compared in terms of potential fertilization. The exchanges between the north-western shelf and the deep sea are quantified. The results illustrate a highly complex spatial variability of the phytoplankton annual cycle and thus, stress the importance of using a 3D model to capture the essential physical-biological interactions that explain the data. [less ▲]

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See detailQuantification of the nitrogen budget in the Black Sea using a 3D coupled hydrodynamical-biogeochemical model
Grégoire, Marilaure ULg; Nezlin, N.; Kostianoy, A. et al

Conference (2000)

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See detailSensitivity of the black sea's ecosystem to physical processes: first results of a high resolution 3D interdisciplinary model
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Nihoul, Jacques ULg et al

in Balopoulos, E.; Chronis, G.; Lipiatou, E. (Eds.) et al International conference. Oceanography of the eastern Mediterranean and Black Sea. Similarities and differences of two interconnected basins (2000)

A hydrodynamical model of the general circulation in the Black Sea has been build up, using the GHER (GeoHydrodynamics and Environment Research) three-dimensional, non-linear, baroclinic, turbulent ... [more ▼]

A hydrodynamical model of the general circulation in the Black Sea has been build up, using the GHER (GeoHydrodynamics and Environment Research) three-dimensional, non-linear, baroclinic, turbulent closure model. A model with 5 km horizontal resolution and 25 vertical levels is used to compute the typical seasonal cycle by forcing the model with climatological monthly mean fields of temperature, salinity and wind stress at the air-sea interface. Furthermore, the river discharges of the Danube, the Dnestr and the Dnepr are taken into account. This high resolulion model resolves the baroclinic instabilities generated by the interactions of the boundary current with the coastline geometry or with the continental shelf/slope topography. A simple ecosystem model defined by a nitrogen cycle is coupled with Ihe hydrodynamical model. The state variables of this model are defined as those which are necessary and sufficient to assess the effects of the physical processes, and in particular of the boundary current instability , on the space time distribution of the primary and secondary productions. The results of the 3D ecohydrodynamic model are compared with CZCS data of surface chlorophyll fields collected during the period from 1978 to 1986. [less ▲]

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See detailCirculation and coastal processes off NW Africa
Elmoussaoui, Abdellali; Djenidi, Salim ULg; Kostianoy, Andrey et al

in Oceanic Fronts and Related Phenomena : Konstantin Fedorov International Memorial Symposium Proceedings (2000)

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See detailDissection of the GHER turbulence closure scheme
Delhez, Eric ULg; Grégoire, Marilaure ULg; Nihoul, Jacques ULg et al

in Journal of Marine Systems (1999), 21(1-4), 379-397

In this paper, the turbulence closure scheme implemented in the GHER hydrodynamic model is described in detail. Two case studies carried out in two contrasting conditions-one in the shallow, tide ... [more ▼]

In this paper, the turbulence closure scheme implemented in the GHER hydrodynamic model is described in detail. Two case studies carried out in two contrasting conditions-one in the shallow, tide dominated, north-western European continental shelf, and the other in the deep Mediterranean Sea-are used to identify the dominant terms of the equation for the turbulent kinetic energy, first theoretically, secondly from the results of the simulations. In both domains, the dominant terms are the local destruction and production terms, the vertical diffusion term and to a smaller degree, the time derivative. Advection and horizontal diffusion turn out to be negligible in most of the relevant cases for such large scale studies. This opens the way to simplifications and optimisations of the numerical models. (C) 1999 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailCoupled 3D eddy-resolving general circulation model and ecosystem model applied to the Black sea.
Grégoire, Marilaure ULg; Beckers, Jean-Marie ULg; Nihoul, Jacques ULg et al

in Ostrovskii, S.; Zatsepin, A. (Eds.) Oceanic Fronts and Related Phenomena (Konstantin Federov International Memorial Symposium) (1999)

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See detailDissection of the GHER Turbulence Closure Scheme
Delhez, Eric ULg; Grégoire, Marilaure ULg; Nihoul, Jacques ULg et al

Poster (1998, May)

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