Lars Golmen

Effects of CO2 on benthic biota: an in situ benthic chamber experiment in Storfjorden (Norway)

Carbon capture and storage (CCS) methods, either sub-seabed or in ocean depths, introduces risk of CO2 leakage and subsequent interaction with the ecosystem. It is therefore important to obtain information on possible effects of CO2. In situ CO2 exposure experiments were carried out twice for 10 days during 2005 using a Benthic Chamber system at 400 m depth in Storfjorden, Norway. pCO2 in the water above the sediment in the chambers was controlled at approximately 500, 5000 and 20,000 μatm, respectively. This article describes the experiment and the results from measured the biological responses within the chamber sediments. The results show effects of elevated CO2 concentrations on biological processes such as increased nanobenthos density. Methane production and sulphate reduction was enhanced in the approximately 5000 μatm chamber.

Sea level oscillations with super-tidal frequency in a coastal embayment of western Norway

Abstract In a coastal embayment near the headland Stad in the northwest of Norway, recent measurements of sea water current and sea level revealed permanent barotropic oscillations with a mean period of 48 min. The sea level oscillations that are superimposed on the signal of the dominating semi-diurnal tide have a mean range of 3–5 cm, while maximum observed values exceed 20 cm. The character of the oscillation is different from numerously reported bay oscillations and seiches of comparable period, which are all transient. In this paper these observations are presented and analysed. Possible artifacts caused by sampling or analysis are investigated, and may be ruled out as an explanation. Due to its permanent character, the only possible energy source for the oscillations seems to be the regular semi-diurnal tide or one of its close constituents.

Objectives of the NeXOS project in developing next generation ocean sensor systems for a more cost-efficient assessment of ocean waters and ecosystems, and fisheries management

The NeXOS project aims to develop new multifunctional sensor systems supporting a number of scientific, technical and societal objectives, ranging from more precise monitoring and modelling of the marine environment to an improved management of fisheries. Several sensors will be developed, based on optical and passive acoustics technologies, addressing key environmental descriptors identified by the European Marine Strategy Framework Directive (MSFD) for Good Environmental Status (GES). Two of the new sensors will also contribute to the European Union Common Fisheries Policy (CFP), with a focus on variables of interest to an Ecosystem Approach to Fisheries (EAF). An objective is the improved cost-efficiency, from procurement to operations, via the implementation of several innovations, such as multiplatform integration, greater reliability through better antifouling management, greater sensor and data interoperability and the creation of market opportunities for European enterprises. Requirements will be further analysed for each new sensor system during the first phase of the project. Those will then be translated into engineering specifications, leading to the development phase. Sensors will then be tested, calibrated, integrated on several platform types, scientifically validated and demonstrated in the field. Translation to production and broad adoption are facilitated by participating industry. Overall, the paper presents an overview of the project objectives and plans for the next four years.

NeXOS, developing and evaluating a new generation of in-situ ocean observation systems

Many changes are occurring in the physical, chemistry and biology processes of the ocean. Understanding how these changes are driven is an element of the key environmental descriptors identified by the European Marine Strategy Framework Directive (MSFD) with the ultimate goal being to protect the resource base upon which marine-related economic and social activities depend. The Directive furthers the ecosystem approach to the management of human activities having an impact on the marine environment, integrating the concepts of environmental protection and sustainable use. To meet these goals, in-situ data are necessary for comprehensive modeling and forecasting of ocean dynamics. Yet, collection of in-situ observations is inherently challenging from the perspective of both time and resources. This paper addresses a new generation of acoustic, optical and fishery in-situ sensors that address these challenges. These sensor systems are multifunctional (single sensor systems addressing several phenomena), can be deployed on a large majority of ocean monitoring systems from surface to the seafloor, and operate for long periods with less maintenance. In addition, at the system and user interface level, the publication of data uses processes and formats conforming to OGC SWE standards and consistent with global ocean observing initiatives and ocean modeling portals such as Copernicus marine environment monitoring services. During the last three years, NeXOS has achieved a number of milestones, providing ten new sensors along with important transverse capabilities for anti-fouling and data management. The optical sensors include monitoring of marine contaminants such as hydrocarbons and components of the carbon cycle. New sensor systems for passive acoustic measurements with extended dynamic range include internal post-processing of acoustic information to reduce communication loads. Two additional sensors (chlorophyll-a and oxygen) have been added to the RECOPESCA system to support an Ecosystem Approach to Fisheries (EAF) for improving measurement of stock-relevant parameters, such as fluorescence (proxy of chlorophyll-a) as well as physical parameters (T, S, Depth) and fish species. Interface with the sensors is through a miniaturized smart sensor interface common to all new NeXOS sensor systems and a PUCK implementation facilitates streamlined platform interfaces. A common toolset for web-enabled and reconfigurable downstream services supports marine databases and data facilitators, from SeaDataNet to GOOS and the Global Earth Observation System of Systems (GEOSS). This paper provides description of sensors and their capabilities along with validation testing.

Validation and demonstration of novel oceanographic sensors on selected measurement platforms in the NeXOS project

This article describes the initial planning and outcomes of validation and demonstration efforts for oceanographic sensors in the EU-funded project NeXOS. The project has developed novel, multi-functional optical and acoustic sensors for environmental monitoring and mapping. These sensors are subject to validation and demonstration in real sea conditions. Procedures for validations are described, followed by examples of successful demonstrations t provided either delayed or real-time, to users through a Sensor Web Enablement capability developed in the project.

NeXOS development plans in ocean optics, acoustics and observing systems interoperability

A growing concern about the health of the world oceans resulting from multiple stressors as for instance effects of climate change and increasing offshore activities leads to the need of better observational tools and strategies. The objective of the NeXOS project is to serve those needs by developing new cost-effective, innovative and compact integrated multifunctional sensor systems for ocean optics, ocean passive acoustics, and an Ecosystem Approach to Fisheries (EAF), which can be deployed from mobile and fixed ocean observing platforms, as well as to develop downstream services for the Global Ocean Observing System, Good Environmental Status of European marine waters and the Common Fisheries Policy.

OCEAN THERMAL ENERGY CONVERSION (OTEC) AND DEEP OCEAN WATER APPLICATIONS (DOWA): MARKET OPPORTUNITIES FOR EUROPEAN INDUSTRY

The IOA International OTEC/DOWA Association, an association created in 1990, aims at informing on worldwide R&D efforts to develop the commercial usage of DOW - Deep Ocean Water. In the past IOA interest for DOW has been focused on its use as the cold source in the OTEC process for supplying electricity. IOA’s review of the most recent results obtained (mainly in USA, Japan, India and Taiwan) indicates that the Deep Ocean Water should be now considered as a renewable resource for “clean” production of many commercial products including not only electricity but also fresh water, food, energy saving, air-conditioning, etc. Technologies to tap into these resources are available and OTEC/DOWA facilities can contribute to the development of isolated coastal areas located in the tropical belt and some sub-tropical areas. But OTEC/DOWA according to the criteria adopted by the European Union Commission for defining the priorities of its Fifth Framework Program has not yet reached the status of “already developed technology” as do wind, photovoltaic, biomass, and other energy resources located in the European continental region.

EGOS-European Group on Ocean Stations a continuously operating Data Buoy programme in the North Atlantic

EGOS; the European Group on Ocean Stations, is a joint European project for the acquistion of meteorological and oceanographic data in the North Atlantic Ocean. The data are telemetered in near real-time from data buoys via satellites to shore, and disseminated via GTS with minimum time-delay to met. centers for use in weather forecasting. Presently EGOS maintains a continuously operational network of 15–25 drifting data buoys and 6–7 moored buoys in the North Atlantic. Data quality is continuously monitored, and reports on the status of the program are issued each month by the Technical Secretariat of EGOS. Meteorological parameters are emphasized, but the sampling programme may be enhanced in the future to also include more oceanographic parameters, and it is anticipated that EuroGOOS may provide and support links to new users of buoy data from EGOS.

Large-Eddy Simulation of Small-Scale Ocean Turbulence Coupled with Buoyant Plumes

To examine the turbulent characteristics of a small-scale ocean (length scale at L=O(103m)) disturbed by buoyant plumes, a numerical experiment is performed by employing Large-eddy simulation technology and two-fluid theories. This includes a simulation of reconstruction of the statistically stationary state of a small-scale ocean and the simulation of two-fluid plumes. For numerical reconstruction of a small-scale ocean, the observation data of the instantaneous flow field on the West Coast of Hawaii Island is applied to the determination of the turbulent structure with the aid of the forced-dissipative mechanism. The dynamics of buoyant droplets is described by an Eulerian scheme with the assumption of treating the droplets as a quasi-fluid. The two-way coupling between turbulent ocean and droplets is performed through exchange sub-models for momentum and mass. The predictions of turbulence spectra indicate that the buoyant plumes improved indistinctly the horizontal turbulent characteristics, however, they significantly modified the temperature spectrum in the lower wavenumber range. For plumes, the dynamics in the regime near the injection exit are dominated by interactions between turbulent ocean and droplets/solution. Outside of this regime, water column of solution is governed by the ocean turbulent flow.