Coupled mooring analysis using CFD with dynamic mooring models is becoming an established field. This is an important step for better predictions of responses of moored marine structures in extreme sea states and also for capturing the low-frequency response correctly. The coupling between the CFD and mooring solvers are most often carried out by exchanging the fairlead/anchor points and fairlead forces. In this paper we will discuss the effects of using (i) viscous fluid flow on a mooring component level (submerged buoys and clump weights) and (ii) the fluid-structure coupling between the viscous fluid solver and the mooring system.
The latest IPCC report on Ocean and Cryosphere in a Changing Climate, which builds upon previous IPCC's reports, established a causal link between anthropogenic impacts and ocean acidification, by noting a significant decrease in the Ocean's uptake of CO2, with consequent damage to Earth's ecosystems, which in turn has traceable repercussions on the Arctic Ocean and then from the Arctic to the Planet Earth. The impact of ocean acidification is not only in the biological ecosystem but also on human activities, such as livelihood, food security, socio-economic security and developing communities. However, who can possibly be held ethically/legally responsible for ocean acidification from a climate justice perspective? Since what happens in the Arctic does not stay there, a more systematic law and policy approach to study options and responses in a multi-level, climate-ethical, global perceptive is needed. This paper sheds light on the legal responses available at global, regional and national levels to ocean acidification in a law of the sea and ocean context, both in the Arctic and from the Arctic. The gaps in legal and policy responses in connection to the ethical climate component will be identified. It will shed light on the planetary limits that humanity needs to stay within in order to maintain the future of the Earth. Since it touches upon questions of legal responsibility, on who is responsible for ocean acidification, it will connect to the “supply side” of fossil fuels production and global extraction projects causing anthropogenic CO2 emissions, one of the major causes of ocean acidification. It will also identify which actors, be they "officials" or "non-officials" (such as international organizations, states, regional institutes, Arctic citizens or even forums) should be held ethically responsible, and who should take action.
The main objective of this research is to present an improved and more accurate formula to estimate the reflection coefficient (K R ) for rubble mound breakwaters. Physical model tests were performed for this purpose and existing data was also considered. The evaluation of existing prediction formulas for K R based on the Iribarren number (ξ) shows that the scatter in the experimental results increases with increasing ξ. This is caused by the wavelength having greater influence on the reflection than the wave height and thus the use of the wave steepness is inappropriate. The influence of potentially dimensionless parameters on the wave reflection from literature was analyzed. The major dimensionless parameters were found to be the relative water depth (h/L) and the structure front slope angle (α). Hence, a formula to estimate wave reflection for rubble mound breakwaters based on these two parameters is proposed.
The power output from many wave energy converters (WECs) is limited by a finite stroke length in the power take-off (PTO) mechanism. As the PTO approaches its maximum stroke length, an end-stop system needs to be engaged to avoid damage to the machinery. Still the on-set of the end-stop is a nonlinear trigger force, a stiff point in the system. In this respect it is similar to how snap loads in the mooring cables affect the system after a period of cable slack. This paper presents a detailed study into the dynamics of end-stop events and snap loads for a WEC. The WEC is a bottom-mounted linear generator connected to a surface buoy via a steel wire. By comparing a linear spring model with three dynamic mooring line models we conclude that large differences are observed in the low-tension and slack regions of the cable during moderate wave loads, while minor differences are seen in the estimated peak tension. By further varying end-stop parameters we observe that the peak tension in the line changes mildly with the axial stiffness for moderate wave heights. The peak tension is surprisingly unaffected by the introduction of a critical damping level to the end-stop system, despite the significant increase in end-stop force which causes the translator to come to a sudden stop. We discuss how the connection between maximum line force and end-stop parameters is highly dependent on the buoy position in the wave at the instant of end-stop onset.
The present paper deals with separation of long-crested regular waves into incident and reflected components. Such methods have been available for several decades for linear waves, but have recently been extended to cover nonlinear waves over horizontal foreshores. The overall goal of the present paper is to extend the separation method for nonlinear regular waves to also cover sloping foreshores. This requires the combination of the existing method with a nonlinear shoaling model. A nonlinear shoaling model was very recently found valid for the shoaling of the primary and bound components in regular waves when the slope angle is positive and mild. In the present paper this shoaling model is utilized and assumed valid also for the de-shoaling of the reflected waves, ie on a negative mild slope angle. However, if the reflected waves are nonlinear the de-shoaling process is much more complicated and will for example cause the release of free waves. Interactions among those free reflected wave components may cause nonlinear interactions not included in the mathematical model. For that reason, the applicability range is limited to mildly nonlinear reflected waves. Using numerical model data with various foreshore slopes, wave nonlinearities and reflection coefficients the reliability of the developed model is examined in detail.
With expanding human uses at sea, the objective of maritime spatial planning (MSP) to promote sustainable coexistence between marine uses becomes an increasingly challenging task. In order to assess coexistence options, both use-use interactions and use-environment interactions are important to explore. Tools for doing cumulative impact assessments (CIA) on the environment provide a means for spatially exploring environmental impacts. Finding inspiration in such ecosystem-based spatial use-environment approaches while drawing on pairwise marine use compatibility knowledge from existing literature, a spatial approach to model potential synergies and conflicts between marine uses through an expert-based scoring system is presented and implemented in SEANERGY, an ArcMap-based opensource toolbox. A test based on Baltic Sea GIS data demonstrates how SEANERGY supplements CIA analyzes with knowledge about potential use-use synergies, potential use-use conflicts, and their spatial extents, useful for optimizing the use of marine space in MSP without putting too much cumulative pressure on the environment.
Marine Spatial Planning (MSP) requires the analysis of the spatial distribution of marine uses and environmental conditions. Such analyzes can be carried out with GIS, but standard GIS programs do not feature a toolbox that combines the most needed functionalities for such analyses. The SPACEA toolbox presented here was created to bundle and adapt existing functionalities in one toolbox. SPACEA consists of several script tools that have been designed to be user-friendly and applicable to different analyzes for MSP. This includes the processing of different input layers with regard to marine uses and environmental conditions. The main functionalities of SPACEA are exemplified in a fictional case study in the Baltic Sea, where the tools are applied to find potentially suitable areas for mussel farming. The tools feature a user-friendly interface and more experienced users may also use the provided sample codes to run it from the python window or as a stand-alone script. As such, the tools can be applied by users with different levels of GIS knowledge and experience.
With expanding human uses at sea, the objective of maritime spatial planning (MSP) to promote sustainable coexistence between marine uses becomes an increasingly challenging task. In order to assess coexistence options, both use-use interactions and use-environment interactions are important to explore. Tools for doing cumulative impact assessments (CIA) on the environment provide a means for spatially exploring environmental impacts. Finding inspiration in such ecosystem-based spatial use-environment approaches while drawing on pairwise marine use compatibility knowledge from existing literature, a spatial approach to model potential synergies and conflicts between marine uses through an expert-based scoring system is presented and implemented in SEANERGY, an ArcMap-based opensource toolbox. A test based on Baltic Sea GIS data demonstrates how SEANERGY supplements CIA analyzes with knowledge about potential use-use synergies, potential use-use conflicts, and their spatial extents, useful for optimizing the use of marine space in MSP without putting too much cumulative pressure on the environment.
There is growing evidence that the ecosystem service (ES) concept can provide valuable input to marine spatial planning (MSP), by highlighting which ecosystem goods and services can be produced from a planning area. ES link the underlying ecosystem processes and functions to the benefits humans can receive from ecosystems (the ecosystem cascade). In this study, we argue that the ecosystem cascade can be used to structure the stock-taking and future scenario analysis in MSP. However, indicators, which are needed for measuring ES, have often been applied in various ways to the different steps of the cascade. Here, we apply a consistent approach to sorting indicators into the cascade. The indicators are presented in an indicator pool that can be used to filter them based on the cascade steps, several quality criteria, and themes. The pool consists of 772 indicators, of which 735 were analyzed. In total, 252 analyzed indicators belong to the provisioning services, 314 indicators to the regulating services and 169 to the cultural services. The indicator pool offers a suitable starting point to select indicators for ES assessments within MSP. Using indicators at the different cascade steps allows the assessment of i) the ecosystem components generating the services and ii) the impacts on ES and their beneficiaries when changes occur in the provision of the services due to planning or management decisions.
Although the concept of ecosystem services has been in use for many decades, its application for policy support is limited, particularly with respect to marine ecosystems. Gaps in the assessments of ecosystem services supply prevent its empirical application. We advance these assessments by providing an assessment tool, which links marine ecosystem components, functions and services, and graphically represents the assessment process and its results. The tool consists of two parts: (i) a matrix following the ecosystem services cascade structure for quantifying the contribution of ecosystem components in the provision of ecosystem services; (ii) and a linkage diagram for visualizing the interactions between the elements. With the aid of the Common International Classification of Ecosystem Services (CICES), the tool was used to assess the relative contribution of a wide range of marine ecosystem components in the supply of ecosystem services in the Latvian marine waters. Results indicate that the tool can be used to assess the impacts of environmental degradation in terms of ecosystem service supply. These impacts could further be valued in socioeconomic terms, as changes in the socioeconomic values derived from the use of ecosystem services. The tool provides an opportunity for conducting a holistic assessment of the ecosystem service supply and communicating the results to marine spatial planning practitioners, and increasing their understanding and use of the ecosystem service concept.