Modelling the influence of Major Baltic Inflows on near-bottom conditions at the entrance of the Gulf of Finland

A coupled hydrodynamic-biogeochemical model was implemented in order to estimate the effects of Major Baltic Inflows on the near-bottom hydrophysical and biogeochemical conditions in the northern Baltic Proper and the western Gulf of Finland during the period 1991-2009. We compared results of a realistic reference run to the results of an experimental run where Major Baltic Inflows were suppressed. Further to the expected overall decrease in bottom salinity, this modelling experiment confirms that in the absence of strong saltwater inflows the deep areas of the Baltic Proper would become more anoxic, while in the shallower areas (western Gulf of Finland) near-bottom average conditions improve. Our experiment revealed that typical estuarine circulation results in the sporadic emergence of short-lasting events of near- bottom anoxia in the western Gulf of Finland due to transport of water masses from the Baltic Proper. Extrapolating our results beyond the modelled period, we speculate that the further deepening of the halocline in the Baltic Proper is likely to prevent inflows of anoxic water to the Gulf of Finland and in the longer term would lead to improvement in near-bottom conditions in the Baltic Proper. Our results reaffirm the importance of accurate representation of salinity dynamics in coupled Baltic Sea models serving as a basis for credible hindcast and future projection simulations of biogeochemical conditions.JRC.H.1-Water Resource

Report on the biogeochemical model of the North-Western European Shelf

The report presents the background of the newly developed marine model covering the North and Celtic Sea. The 3d-model includes all relevant hydrodynamical drivers (tides, currents, water temperature and salinity) and a biogeochemical model of the lower trophic foodweb including essential dissolved nutrients (nitrate, ammonium, phosphate, silicate, carbon and oxygen) and several phytoplankton groups. The moel results are mainly assessed for the indicators, used for the assessment of descriptor 5 ("eutrophication") within the EU Marine Strategy Framwork Directive (MSFD). The coupled model was used to simulate the present state (covering the period 2005 - 2012) and its results are compared and validated, using a variety of different datasets of observations.JRC.D.2-Water and Marine Resource

The Role of Citizen Science in Promoting Ocean and Water Literacy in School Communities: The ProBleu Methodology

Human activities continue to degrade oceanic, coastal and inland waters. The generational change in the role of society in actively looking after the health of water resources can be achieved through the expansion of ocean and water literacy in schools. The Network of European Blue Schools established under the EU4Ocean Coalition for Ocean Literacy has improved ocean and water literacy; however, this Network needs to grow and be supported. Here, we present ProBleu, a recently funded EU project that will expand and support the Network, partly through the use of citizen science. The core of the proposed methodology is facilitating school activities related to ocean and water literacy through funding calls to sustain and enrich current school activities, and kick-start and support new activities. The outcomes of the project are anticipated to have widespread and long-term impacts across society, and oceanic, coastal and inland water environments

Carbon on the Northwest European Shelf: Contemporary Budget and Future Influences

A carbon budget for the northwest European continental shelf seas (NWES) was synthesized using available estimates for coastal, pelagic and benthic carbon stocks and flows. Key uncertainties were identified and the effect of future impacts on the carbon budget were assessed. The water of the shelf seas contains between 210 and 230 Tmol of carbon and absorbs between 1.3 and 3.3 Tmol from the atmosphere annually. Off-shelf transport and burial in the sediments account for 60–100 and 0–40% of carbon outputs from the NWES, respectively. Both of these fluxes remain poorly constrained by observations and resolving their magnitudes and relative importance is a key research priority. Pelagic and benthic carbon stocks are dominated by inorganic carbon. Shelf sediments contain the largest stock of carbon, with between 520 and 1600 Tmol stored in the top 0.1 m of the sea bed. Coastal habitats such as salt marshes and mud flats contain large amounts of carbon per unit area but their total carbon stocks are small compared to pelagic and benthic stocks due to their smaller spatial extent. The large pelagic stock of carbon will continue to increase due to the rising concentration of atmospheric CO2, with associated pH decrease. Pelagic carbon stocks and flows are also likely to be significantly affected by increasing acidity and temperature, and circulation changes but the net impact is uncertain. Benthic carbon stocks will be affected by increasing temperature and acidity, and decreasing oxygen concentrations, although the net impact of these interrelated changes on carbon stocks is uncertain and a major knowledge gap. The impact of bottom trawling on benthic carbon stocks is unique amongst the impacts we consider in that it is widespread and also directly manageable, although its net effect on the carbon budget is uncertain. Coastal habitats are vulnerable to sea level rise and are strongly impacted by management decisions. Local, national and regional actions have the potential to protect or enhance carbon storage, but ultimately global governance, via controls on emissions, has the greatest potential to influence the long-term fate of carbon stocks in the northwestern European continental shelf

Carbon on the Northwest European Shelf: Contemporary Budget and Future Influences

© Copyright © 2020 Legge, Johnson, Hicks, Jickells, Diesing, Aldridge, Andrews, Artioli, Bakker, Burrows, Carr, Cripps, Felgate, Fernand, Greenwood, Hartman, Kröger, Lessin, Mahaffey, Mayor, Parker, Queirós, Shutler, Silva, Stahl, Tinker, Underwood, Van Der Molen, Wakelin, Weston and Williamson. A carbon budget for the northwest European continental shelf seas (NWES) was synthesized using available estimates for coastal, pelagic and benthic carbon stocks and flows. Key uncertainties were identified and the effect of future impacts on the carbon budget were assessed. The water of the shelf seas contains between 210 and 230 Tmol of carbon and absorbs between 1.3 and 3.3 Tmol from the atmosphere annually. Off-shelf transport and burial in the sediments account for 60–100 and 0–40% of carbon outputs from the NWES, respectively. Both of these fluxes remain poorly constrained by observations and resolving their magnitudes and relative importance is a key research priority. Pelagic and benthic carbon stocks are dominated by inorganic carbon. Shelf sediments contain the largest stock of carbon, with between 520 and 1600 Tmol stored in the top 0.1 m of the sea bed. Coastal habitats such as salt marshes and mud flats contain large amounts of carbon per unit area but their total carbon stocks are small compared to pelagic and benthic stocks due to their smaller spatial extent. The large pelagic stock of carbon will continue to increase due to the rising concentration of atmospheric CO2, with associated pH decrease. Pelagic carbon stocks and flows are also likely to be significantly affected by increasing acidity and temperature, and circulation changes but the net impact is uncertain. Benthic carbon stocks will be affected by increasing temperature and acidity, and decreasing oxygen concentrations, although the net impact of these interrelated changes on carbon stocks is uncertain and a major knowledge gap. The impact of bottom trawling on benthic carbon stocks is unique amongst the impacts we consider in that it is widespread and also directly manageable, although its net effect on the carbon budget is uncertain. Coastal habitats are vulnerable to sea level rise and are strongly impacted by management decisions. Local, national and regional actions have the potential to protect or enhance carbon storage, but ultimately global governance, via controls on emissions, has the greatest potential to influence the long-term fate of carbon stocks in the northwestern European continental shelf

Modelling marine sediment biogeochemistry: Current knowledge gaps, challenges, and some methodological advice for advancement

The benthic environment is a crucial component of marine systems in the provision of ecosystem services, sustaining biodiversity and in climate regulation, and therefore important to human society. With the contemporary increase in computational power, model resolution and technological improvements in quality and quantity of benthic data, it is necessary to ensure that benthic systems are appropriately represented in coupled benthic-pelagic biogeochemical and ecological modelling studies. In this paper we focus on five topical challenges related to various aspects of modelling benthic environments: organic matter reactivity, dynamics of benthic-pelagic boundary layer, microphytobenthos, biological transport and small-scale heterogeneity, and impacts of episodic events. We discuss current gaps in their understanding and indicate plausible ways ahead. Further, we propose a three-pronged approach for the advancement of benthic and benthic-pelagic modelling, essential for improved understanding, management and prediction of the marine environment. This includes: (A) development of a traceable and hierarchical framework for benthic-pelagic models, which will facilitate integration among models, reduce risk of bias, and clarify model limitations; (B) extended cross-disciplinary approach to promote effective collaboration between modelling and empirical scientists of various backgrounds and better involvement of stakeholders and end-users; (C) a common vocabulary for terminology used in benthic modelling, to promote model development and integration, and also to enhance mutual understanding

Reproducible and relocatable regional ocean modelling: Fundamentals and practices

In response to an increasing demand for bespoke or tailored regional ocean modelling configurations, we outline fundamental principles and practices that can expedite the process to generate new configurations. The paper develops the principle of Reproducibility and advocates adherence by presenting benefits to the community and user. The elements to this principle are reproducible workflows and standardised assessment, with additional effort over existing working practices being balanced against the added value generated. The paper then decomposes the complex build process, for a new regional ocean configuration, into stages and presents guidance, advice and insight on each component. This advice is compiled from across the user community, is presented in the context of NEMOv4, though aims to transcend NEMO version. Detail and region specific worked examples are linked in companion repositories and DOIs. The aim is to broaden the user community skill base, and to accelerate development of new configurations in order to increase available time exploiting the configurations

Modeling the Response of the Gulf of Finland Ecosystem to Changing Climate

Direct and indirect effects of changing meteorological conditions include alterations in nutrient cycling, timing and extent of algal blooms, species composition and oxygen dynamics of the Baltic coastal ecosystems. In this study the one-dimensional water column model GOTM coupled with a modified version of the biogeochemical model ERGOM was implemented to study the effects of changes in meteorological forcing associated with climate change on dynamics of nutrients, phytoplankton and dissolved oxygen in the central part of the Gulf of Finland. The modeling period from 1997 to 2008 (11 years) was chosen. Initial distributions of salinity, temperature and biogeochemical parameters from available measurement data were prescribed. As a reference run representing the present conditions of the ecosystem, model results with real atmospheric forcing were used. The model results were validated using observational data from the HELCOM monitoring program. The first three years of the simulation were used as a spin-up period. For the rest of the period modeled ecosystem sensitivity to variations in wind speed, air temperature, cloud cover and precipitation were analyzed separately and in a combination. The ranges of variations were chosen in agreement with recent publications on the assessment of climate change in the Baltic Sea region. Results have shown that increase in precipitation does not have any remarkable effect on the ecosystem. Increase in wind speed intensifies water mixing thus providing more nutrients for phytoplankton, but also slightly decreases water temperature. Change in cloud cover negatively affects phytoplankton growth due to decrease in light availability during biologically active period. Increased air temperature influences phytoplankton growth rates, leading to enhanced sedimentation of organic matter and near-bottom oxygen consumption. The scenario which combined all the previous, showed similar results as change in air temperature only, but slightly closer to the reference run due to action of wind speed and cloud cover. The study has shown that regardless of known limitations of one-dimensional models, they are a valuable tool in the investigation of marine ecosystem properties and their sensitivity to changes in the forcing parameters.JRC.DDG.H.3-Global environement monitorin