In this paper a generic methodology is presented that allows the impacts of climate change on wave energy generation from a wave energy converter (WEC) to be quantified. The methodology is ...illustrated by application to the Wave Hub site off the coast of Cornwall, UK. Control and future wave climates were derived using wind fields output from a set of climate change experiments. Control wave conditions were generated from wind data between 1961 and 2000. Future wave conditions were generated using two IPCC wind scenarios from 2061 to 2100, corresponding to intermediate and low greenhouse gas emissions (IPCC scenarios A1B and B1 respectively). The quantitative comparison between future scenarios and the control condition shows that the available wave power will increase by 2–3% in the A1B scenario. In contrast, the available wave power in the B1 scenario will decrease by 1–3%, suggesting, somewhat paradoxically, that efforts to reduce greenhouse gas emissions may reduce the wave energy resource. Meanwhile, the WEC energy will yield decrease by 2–3% in both A1B and B1 scenarios, which is mainly due to the relatively low efficiency of energy extraction from steeper waves by the specific WEC considered. Although those changes are relatively small compared to the natural variability, they may have significance when considered over the lifetime of a wave energy farm. Analysis of downtime under low and high thresholds suggests that the distribution of wave heights at the Wave Hub will have a wider spread due to the impacts of climate change, resulting in longer periods of generation loss. Conversely, the estimation of future changes in joint wave height-period distribution provides indications on how the response and power matrices of WECs could be modified in order to maintain or improve energy extraction in the future.
► A generic methodology for assessing the impacts of climate change on wave energy generation is presented. ► The methodology is illustrated by application to the Wave Hub site off the coast of Cornwall, UK. ► Comparison of future scenarios and control conditions shows statistically significant changes. ► Changes are small in comparison to natural variability, but have significance over scheme lifetime. ► Analysis of downtime suggests that climate change will result in longer periods of generation loss.
Background
Aim of this experimental study was to compare haemodynamic effects and outcome with early administration of amiodarone and adrenaline vs. adrenaline alone in pigs with prolonged ...ventricular fibrillation (VF).
Methods
After 8 min of untreated VF arrest, bolus doses were administered of adrenaline (0.02 mg/kg) and either amiodarone (5 mg/kg) or saline (n = 8 per group) after randomisation. Cardiopulmonary resuscitation (CPR) was commenced immediately after drug administration, and defibrillation was attempted 2 min later. CPR was resumed for another 2 min after each defibrillation attempt, and the same dose of adrenaline was given every 4th minute during CPR. Haemodynamic monitoring and mechanical ventilation continued for 6 h after return of spontaneous circulation (ROSC), and the pigs were euthanised at 48 h. Researchers were blinded for drug groups throughout the study.
Results
There was no difference in rates of ROSC and 48‐h survival with amiodarone vs. saline (5/8 vs. 7/8 and 0/8 vs. 3/8, respectively). Diastolic aortic pressure and coronary perfusion pressure were significantly lower with amiodarone during CPR and 1 min after ROSC (P < 0.05). The number of electric shocks required for terminating VF, time to ROSC and adrenaline dose were significantly higher with amiodarone (P < 0.01). The incidence of post‐resuscitation tachyarrhythmias tended to be higher in the saline group (P = 0.081).
Conclusion
Early administration of amiodarone did not improve ROSC or 48‐h survival rates, and was associated with worse haemodynamics in this swine model of cardiac arrest.
The operation of a compact and busy preclinical laboratory comes with many challenges but also presents some surprising opportunities. Running a mouse and rat animal facility and full laboratory with ...a procedures room, multiple imaging modalities, radiochemical and cells lab, in a 100 m2 space has proven very functional from a managerial, organizational and multitasking aspect, as everything and everyone is close and easy to coordinate. Space limitations mainly affect washing, waste and supplies storage, adding heavy big equipment such as a biosafety cabinet, and hosting staff and occasional visitors. Operating the animal facility necessitates thorough sterilizations of cages and equipment in order to avoid cross-contamination due to receipt of animals from different breeders and health status. Procedure rooms are strategically organized to fit many needs, with the help of modern compact experimental equipment. The all in - all out operation, ability of close supervision, proximity of all laboratories, and good collaboration of everyone involved overcomes the confined space and allows for a rather convenient workflow. Radioprotection is addressed by using appropriate equipment and organizing the work accordingly, and exposure limits can be kept to the minimum for the public (1 mSv/year). Our experience proves that with good organization, resourcefulness and teamwork, less is more!
Within the framework of the Copernicus Marine Environment Monitoring Service (CMEMS), an operational wave forecasting system for the Mediterranean Sea has been implemented by the Hellenic Centre for ...Marine Research (HCMR) and evaluated through a series of preoperational tests and subsequently for 1 full year of simulations (2014). The system is based on the WAM model and it has been developed as a nested sequence of two computational grids to ensure that occasional remote swell propagating from the North Atlantic correctly enters the Mediterranean Sea through the Strait of Gibraltar. The Mediterranean model has a grid spacing of 1∕24∘. It is driven with 6-hourly analysis and 5-day forecast 10 m ECMWF winds. It accounts for shoaling and refraction due to bathymetry and surface currents, which are provided in offline mode by CMEMS. Extensive statistics on the system performance have been calculated by comparing model results with in situ and satellite observations. Overall, the significant wave height is accurately simulated by the model while less accurate but reasonably good results are obtained for the mean wave period. In both cases, the model performs optimally at offshore wave buoy locations and well-exposed Mediterranean subregions. Within enclosed basins and near the coast, unresolved topography by the wind and wave models and fetch limitations cause the wave model performance to deteriorate. Model performance is better in winter when the wave conditions are well defined. On the whole, the new forecast system provides reliable forecasts. Future improvements include data assimilation and higher-resolution wind forcing.
Analytical solutions to an extended version of the one-line model for shoreline change are derived in this paper for two cases: (1) shoreline change when the evolution of an alongshore position is a ...known function of time; and (2) shoreline change within a groyne compartment. The solutions extend existing analytic approaches by accounting for arbitrarily time-varying wave conditions. Explicit solutions are obtained by means of integral transform techniques. The generalized expressions can account for time-varying wave conditions, for an initial beach shape which is an arbitrary function of position, and for sources/sinks of sediment that are a known function of time and space. Example applications are described and the impact that a time-varying wave forcing can have on beach development is investigated. In contrast to previous analytic work, changes in shoreline evolution rate in response to the continuously changing wave conditions in a time series are revealed. Apart from being a more realistic tool for a fast preliminary estimation of long-term shoreline change, the new solutions are also a valuable independent means for validating numerical one-line models.
The Copernicus Marine Environment Monitoring Service (CMEMS) provides regular and systematic reference information on the physical and biogeochemical ocean and sea-ice state for the global ocean and ...the European regional seas. CMEMS serves a wide range of users (more than 15,000 users are now registered to the service) and applications. Observations are a fundamental pillar of the CMEMS value-added chain that goes from observation to information and users. Observations are used by CMEMS Thematic Assembly Centres (TACs) to derive high-level data products and by CMEMS Monitoring and Forecasting Centres (MFCs) to validate and constrain their global and regional ocean analysis and forecasting systems. This paper presents an overview of CMEMS, its evolution, and how the value of in situ and satellite observations is increased through the generation of high-level products ready to be used by downstream applications and services. The complementary nature of satellite and in situ observations is highlighted. Long-term perspectives for the development of CMEMS are described and implications for the evolution of the in situ and satellite observing systems are outlined. Results from Observing System Evaluations (OSEs) and Observing System Simulation Experiments (OSSEs) illustrate the high dependencies of CMEMS systems on observations. Finally future CMEMS requirements for both satellite and in situ observations are detailed.
The Mediterranean Forecasting System produces operational analyses and reanalyses and 10 d forecasts for many essential ocean variables (EOVs), from currents, temperature, salinity, and sea level to ...wind waves and pelagic biogeochemistry. The products are available at a horizontal resolution of 1/24.sup." (approximately 4 km) and with 141 unevenly spaced vertical levels.
There is a general scarcity of oceanic observations that concurrently examine air-sea interactions, coastal-open-ocean processes and physical-biogeochemical processes, in appropriate spatiotemporal ...scales and under continuous, long-term data acquisition schemes. In the Mediterranean Sea, the resulting knowledge gaps and observing challenges increase due to its oligotrophic character, especially in the eastern part of the basin. The oligotrophic open Cretan Sea's biogeochemistry is considered to be representative of a greater Mediterranean area up to 10.sup.6 km.sup.2, and understanding its features may be useful on even larger oceanic scales, since the Mediterranean Sea has been considered a miniature model of the global ocean. The spatiotemporal coverage of biogeochemical (BGC) observations in the Cretan Sea has progressively increased over the last decades, especially since the creation of the POSEIDON observing system, which has adopted a multiplatform, multivariable approach, supporting BGC data acquisition. The current POSEIDON system's status includes open and coastal sea fixed platforms, a Ferrybox (FB) system and Bio-Argo autonomous floats that remotely deliver fluorescence as a proxy of chlorophyll-a (Chl-a), O.sub.2, pH and pCO.sub.2 data, as well as BGC-related physical variables. Since 2010, the list has been further expanded to other BGC (nutrients, vertical particulate matter fluxes), ecosystem and biodiversity (from viruses up to zooplankton) variables, thanks to the addition of sediment traps, frequent research vessel (R/V) visits for seawater-plankton sampling and an acoustic Doppler current profiler (ADCP) delivering information on macrozooplankton-micronekton vertical migration (in the epipelagic to mesopelagic layer). Gliders and drifters are the new (currently under integration to the existing system) platforms, supporting BGC monitoring. Land-based facilities, such as data centres, technical support infrastructure, calibration laboratory and mesocosms, support and give added value to the observatory. The data gathered from these platforms are used to improve the quality of the BGC-ecosystem model predictions, which have recently incorporated atmospheric nutrient deposition processes and assimilation of satellite Chl-a data. Besides addressing open scientific questions at regional and international levels, examples of which are presented, the observatory provides user-oriented services to marine policy makers and the society, and is a technological test bed for new and/or cost-efficient BGC sensor technology and marine equipment. It is part of European and international observing programs, playing a key role in regional data handling and participating in harmonization and best practices procedures. Future expansion plans consider the evolving scientific and society priorities, balanced with sustainable management.
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