69 research outputs found

    Eastern Mediterranean biogeochemical flux model: simulations of the pelagic ecosystem

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    International audienceDuring the second phase (2003?2006) of the Mediterranean ocean Forecasting System Project (MFS) named Toward Environmental Predictions (MFSTEP) one of the three major aims was the development of numerical forecasting systems. In this context a generic Biochemical Flux Model (BFM) was developed and coupled with hydrodynamic models already operating at basin scale as well as at regional areas. In the Eastern Mediterranean basin the BFM was coupled with the Aegean Levantine Eddy Resolving MOdel (ALERMO). The BFM is a generic highly complex model based on ERSEM and although a detailed description of the model and its sub models is beyond the scope of this work a short presentation of the main processes, paying emphasis on the parameter values used is presented. Additionally the performance of the model is evaluated with some preliminary results being qualitatively compared against field observations. The model at its present form is rather promising reproducing all major important features even though there are inefficiencies mostly related to primary and bacterial productivity rates

    Assessing the phenomenology of the Cretan Sea shelf area using coupling modelling techniques

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    International audienceIn this work the ability of nesting two hydrodynamical models, the high-resolution Cretan Sea shelf model and the lower resolution regional ALERMO model, was investigated. A new database was developed by objectively analysing raw climatological data from the MODB database enriched with in situ measurements collected by the Institute of Marine Biology of Crete. Prior to nesting with the ALERMO model, the Cretan Sea model was integrated using this new hydrological database, in order to investigate the capability of the model setup to describe the phenomenology of the Cretan Sea. Results show that the model can successfully reproduce the complex general circulation characteristics of the area, such as the dipole of a cyclone and an anticyclone, and the flow reversal between winter and summer. As a next step, the shelf-model was one-way nested with the ALERMO model and was integrated on a climatological basis. The evolution of the circulation characteristics of the Cretan Sea was compared, qualitatively and quantitatively, against the results of the regional model, and proved that the nesting between the two models can provide reliable information while overcoming at the same time the computational constraints imposed by high-resolution models

    Sensitivity of the N. AEGEAN SEA ecosystem to Black Sea Water inputs

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    The effect of Black Sea Water (BSW) inputs on the North Aegean Sea productivity and food web dynamics was investigated, by means of sensitivity simulations, investigating the effect of the inflowing BSW, in terms of inorganic nutrients and dissolved organic matter. The model used has been successfully applied in the area in the past and extensively presented. Considering the importance of the microbial loop in the ecosystem functioning, the role of the dissolved organics and in order to achieve a more realistic representation of the Dissolved Organic Matter pool, the bacteria sub-model was appropriately revised. The importance of the microbial loop is highlighted by the carbon fluxes where almost 50% of carbon is channelled within it. The impact of dissolved organic matter (DOM) (in the inflowing to the Aegean Sea, BSW) appears to be stronger than the impact of dissolved inorganic nutrients, showing a more extended effect over the N Aegean. Bacterial production and biomass is more strongly affected in the simulations by modified DOM, unlike phytoplankton biomass and production, which are more dependent on the inflowing nutrients and particularly phosphorus (inorganic and dissolved organic). In the phytoplankton composition, the dinoflagellates appear to be mostly affected, being favoured by higher nutrient availability at the expense of all other groups, particularly picoplankton, indicating a shift to a more classical food chain

    The Mediterranean Moored Multi-sensor Array (M3A): system development and initial results

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    International audienceOperational forecasting of ocean circulation and marine ecosystem fluctuations requires multi-parametric real-time measurements of physical and biochemical properties. The architecture of a system that is able to provide such measurements from the upper-thermocline layers of the Mediterranean Sea is described here. The system was developed for the needs of the Mediterranean Forecasting System and incorporates state-of-the-art sensors for optical and chemical measurements in the upper 100 m and physical measurements down to 500 m. Independent moorings that communicate via hydro-acoustic modems are hosting the sensors. The satellite data transfer and the large autonomy allow for the operation of the system in any open-ocean site. The system has been in pre-operational use in the Cretan Sea since January 2000. The results of this pilot phase indicate that multi-parametric real-time observations with the M3A system are feasible, if a consistent maintenance and re-calibration program is followed. The main limitations of the present configuration of M3A are related: (a) to bio-fouling that primarily affects the turbidity and secondarily affects the other optical sensors, and (b) to the limited throughput of the currently used satellite communication system. Key words. Atmospheric composition and structure (instruments and techniques.) Oceanography: general (ocean prediction) Oceanography: physical (upper ocean process

    Strengthening Europe's Capability in Biological Ocean Observations

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    This publication is primarily aimed at stakeholders involved in ocean observing, spanning diverse roles from commissioning, managing, funding and coordinating, to developing, implementing, or advising on, ocean observation programmes. Such programmes will have strategic and policy drivers but their main purpose may vary from predominantly researchdriven scientific purposes to environmental monitoring for providing data and reporting to legally-binding regulations or directives. The main focus is on European capabilities but set in a global context with the various actors spanning a variety of geographical scales from national to regional and European. Key stakeholder organizations include environmental or other agencies; marine research institutions, their researchers and operators; international and regional ocean observing initiatives and programmes; national, regional and European policy makers and their advisors; national stations for observations; etc.). It will also be of interest to the wider marine and maritime research and policy community. The main aim of the publication is to increase the relevance of current (and future) European biological ocean observation capacity to strengthen global efforts towards our understanding of the ocean and enhance marine biodiversity conservation, for maintaining a healthy ocean for healthy societies. This document explains why biological ocean observations are needed to assess progress against national and international conservation targets, the Sustainable Development Goals (SDGs), the Blue Growth agenda and to contribute to key EU directives including the Marine Strategy Framework Directive (MSFD). To achieve this, the publication highlights the need of biological ocean observations to reflect clearly defined hypotheses about potential causes of change, including the combined impacts of local and global drivers, and to support the management of our impacts on the ocean. Additionally, it calls for flexible biological ocean observing programmes to capture the relevant drivers operating at multiple spatial scales, by networking and integration of ongoing monitoring programmes, methodological standardization and appropriate policies of data integration and dissemination. It then presents key variables, elements and information products to inform on the status and trends of marine biodiversity

    Strengthening Europe’s capability in biological ocean observations

    Get PDF
    This publication is primarily aimed at stakeholders involved in ocean observing, spanning diverse roles from commissioning, managing, funding and coordinating, to developing, implementing, or advising on, ocean observation programmes. Such programmes will have strategic and policy drivers but their main purpose may vary from predominantly researchdriven scientific purposes to environmental monitoring for providing data and reporting to legally-binding regulations or directives. The main focus is on European capabilities but set in a global context with the various actors spanning a variety of geographical scales from national to regional and European. Key stakeholder organizations include environmental or other agencies; marine research institutions, their researchers and operators; international and regional ocean observing initiatives and programmes; national, regional and European policy makers and their advisors; national stations for observations; etc.). It will also be of interest to the wider marine and maritime research and policy community. The main aim of the publication is to increase the relevance of current (and future) European biological ocean observation capacity to strengthen global efforts towards our understanding of the ocean and enhance marine biodiversity conservation, for maintaining a healthy ocean for healthy societies. This document explains why biological ocean observations are needed to assess progress against national and international conservation targets, the Sustainable Development Goals (SDGs), the Blue Growth agenda and to contribute to key EU directives including the Marine Strategy Framework Directive (MSFD). To achieve this, the publication highlights the need of biological ocean observations to reflect clearly defined hypotheses about potential causes of change, including the combined impacts of local and global drivers, and to support the management of our impacts on the ocean. Additionally, it calls for flexible biological ocean observing programmes to capture the relevant drivers operating at multiple spatial scales, by networking and integration of ongoing monitoring programmes, methodological standardization and appropriate policies of data integration and dissemination. It then presents key variables, elements and information products to inform on the status and trends of marine biodiversity. The Future Science Brief finishes by recommending priorities for enhancing relevant and integrated current biological ocean observing capacity in Europe
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