Extreme atmospheric-marine events, known as medicanes (short for "Mediterranean hurricanes"), have affected the Mediterranean basin in recent years, resulting in extensive coastal flooding and storm ...surges, and have occasionally been responsible for several casualties. Considering that the development mechanism of these events is similar to tropical cyclones, it is plausible that these phenomena are strongly affected by sea surface temperatures (SSTs) during their development period (winter and autumn seasons). In this study, we compared satellite data and the numerical reanalysis of SSTs from 1969 to 2023 with in situ data from dataloggers installed at different depths off the coast of southeastern Sicily as well as from data available on Argo floats on the Mediterranean basin. A spectral analysis was performed using a continuous wavelet transform (CWT) for each SST time series to highlight the changes in SSTs prior to the occurrence of Mediterranean Hurricanes as well as the energy content of the various frequencies of the SST signal. The results revealed that decreases in SST occurred prior to the formation of each Mediterranean hurricane, and that this thermal drop phenomenon was not observed in intense extra-tropical systems. The spectral analyses revealed that high CWT coefficients representing high SST energy contents were observed before the occurrence of a Mediterranean hurricane. This information may provide a useful fingerprint for distinguishing Mediterranean hurricanes from common seasonal storms at the onset of these events.
Over the last few years, several authors have presented contrasting models to describe the response of boulders to extreme waves, but the absence of direct observation of movements has hindered the ...evaluation of these models. The recent development of online video-sharing platforms in coastal settings has provided the opportunity to monitor the evolution of rocky coastlines during storm events. In September 2018, a surveillance camera of the Marine Protected Area of Plemmirio recorded the movement of several boulders along the coast of Maddalena Peninsula (Siracusa, Southeastern Sicily) during the landfall of the Mediterranean tropical-like cyclone (Medicane) Zorbas. Unmanned autonomous vehicle (UAV) photogrammetric and terrestrial laser scanner (TLS) surveys were performed to reconstruct immersive virtual scenarios to geometrically analyze the boulder displacements recorded in the video. Analyses highlighted that the displacements occurred when the boulders were submerged as a result of the impact of multiple small waves rather than due to a single large wave. Comparison between flow velocities obtained by videos and calculated through relationships showed a strong overestimation of the models, suggesting that values of flow density and lift coefficient used in literature are underestimated.
This 2-year study was aimed to investigate the early effects of protection measures on fish assemblage in the Plemmirio marine reserve and to evaluate its level of enforcement. Sampling was carried ...out by means of underwater visual census techniques in four sampling sites within the reserve boundaries and eight outside the reserve. Results showed significant inside/outside differences in the multivariate abundance of fish assemblage. These results were confirmed and exemplified by significant univariate differences between locations for total abundance, Species Richness and diversity of the fish assemblage; values of these metrics were higher inside the reserve than outside. Small fish size and species of low and medium fishing value did not display significant inside/outside differences in abundances whereas medium, large size fish and high value species showed abundances significantly higher inside the marine reserve. Protection effects were particularly evident for large specimens of high fishing value, most of which were exclusively found inside the reserve (Diplodus puntazzo, Epinephelus costae, Mycteroperca rubra, Scorpaena scrofa, Spondyliosoma cantharus, Sciaena umbra and Epinephelus marginatus). The present study provides evidence of a reserve effect on fish populations after only five years since its establishment. This is an extraordinary result likely due to the high level of enforcement observed inside the Plemmirio MPA.
► We censused fish assemblages inside and outside a Mediterranean marine reserve. ► Statistical analyses showed significant inside/outside differences. ► Results provided evidence of a reserve effect on fish populations ► Large size fish and high value species were more abundant inside the reserve. ► The observed reserve effect was likely due to the high level of enforcement.
The fangtooth moray, Enchelycore anatina (Lowe, 1838), native to the eastern Atlantic Ocean but also known from eastern sections of the Mediterranean, is recorded for the first time from Maltese ...coastal waters in the central Mediterranean. This record is the westernmost one within the Mediterranean and the observed E. anatina individual co-occurred with an individual of Muraena helena Linnaeus, 1758.
This 2-year study was aimed to investigate the early effects of protection measures on fish assemblage in the Plemmirio marine reserve and to evaluate its level of enforcement. Sampling was carried ...out by means of underwater visual census techniques in four sampling sites within the reserve boundaries and eight outside the reserve. Results showed significant inside/outside differences in the multivariate abundance of fish assemblage. These results were confirmed and exemplified by significant univariate differences between locations for total abundance, Species Richness and diversity of the fish assemblage; values of these metrics were higher inside the reserve than outside. Small fish size and species of low and medium fishing value did not display significant inside/outside differences in abundances whereas medium, large size fish and high value species showed abundances significantly higher inside the marine reserve. Protection effects were particularly evident for large specimens of high fishing value, most of which were exclusively found inside the reserve (Diplodus puntazzo, Epinephelus costae, Mycteroperca rubra, Scorpaena scrofa, Spondyliosoma cantharus, Sciaena umbra and Epinephelus marginatus). The present study provides evidence of a reserve effect on fish populations after only five years since its establishment. This is an extraordinary result likely due to the high level of enforcement observed inside the Plemmirio MPA.
The energy sector is undergoing substantial changes in order to promote better efficiency, increase the use of renewable energy, reduce emissions and effectively deploy technologies to trade off ...costs and benefits One emerging solution is the application of the Power-to-Gas technology, which can be used for different purposes. In recent years, Power-to-Gas has been studied to understand the role it could play in the electrical system. This paper has the aims of analysing the existing literature about the Power-to-Gas technology in detail, by considering some solutions that have a direct impact on the electrical system (in particular electrolyser and CO2 production) and applications in the different sectors of the electricity value chain (i.e., generation, transmission, distribution and utilisation). This paper sets out the conceptual aspects that are necessary to include Power-to-Gas facilities in a more comprehensive analysis framework of the operation of the electrical system in various sectors. Some perspectives concerning new Power-to-Gas applications are also presented for each sector, and some promising aspects that are expected to play a relevant role in the future technical and economic evolution of electrical systems are discussed.
•Power-to-Gas (P2G) could play a role in the future electrical system.•The conceptual aspects to include P2G in the electrical system operation are presented.•The literature on P2G applications to the electrical sectors is reviewed.•New perspectives for P2G applications are discussed.•P2G can be used by global prosumers that handle multi-energy facilities in a coordinated way.
The solutions recommended by international roadmaps and technical reports on smart metering refer to interval metering with time resolutions higher than 15 min to 1 h as traditionally used. Based on ...the characteristics of the users' power patterns in distribution networks, this article shows that in practical cases the resolutions of the traditional metering are not sufficient to assess peak power and network losses effectively. Effective interval metering solutions should have resolutions of one minute or less. Moreover, this article shows the advantages of assessing the average power peak (amplitude and duration) and estimating the network losses through innovative solutions beyond interval metering, based on event-driven energy metering. The use of EDM significantly enhances the quality of pattern representation and reduces the amount of data required with respect to high-resolution interval metering. Based on the Pareto analysis of conflicting objectives, a novel procedure to set up the EDM thresholds is presented. The applications shown use real data and refer to a single user, some users connected to a distribution network feeder, and many users connected to a large distribution system. The EDM benefits are quantified using specific indicators that consider energy losses and peak power.
In the power and energy systems area, a progressive increase of literature contributions that contain applications of metaheuristic algorithms is occurring. In many cases, these applications are ...merely aimed at proposing the testing of an existing metaheuristic algorithm on a specific problem, claiming that the proposed method is better than other methods that are based on weak comparisons. This ‘rush to heuristics’ does not happen in the evolutionary computation domain, where the rules for setting up rigorous comparisons are stricter but are typical of the domains of application of the metaheuristics. This paper considers the applications to power and energy systems and aims at providing a comprehensive view of the main issues that concern the use of metaheuristics for global optimization problems. A set of underlying principles that characterize the metaheuristic algorithms is presented. The customization of metaheuristic algorithms to fit the constraints of specific problems is discussed. Some weaknesses and pitfalls that are found in literature contributions are identified, and specific guidelines are provided regarding how to prepare sound contributions on the application of metaheuristic algorithms to specific problems.
Multienergy systems (MES), in which multiple energy vectors are integrated and optimally operated, are key assets in low-carbon energy systems. Multienergy interactions of distributed energy ...resources via different energy networks generate the so-called distributed MES (DMES). While it is now well recognized that DMES can provide power system flexibility by shifting across different energy vectors, it is essential to have a systematic discussion on the main features of such flexibility. This article presents a comprehensive overview of DMES modeling and characterization of flexibility applications. The concept of "multienergy node" is introduced to extend the power node model, used for electrical flexibility, in the multienergy case. A general definition of DMES flexibility is given, and a general mathematical and graphical modeling framework, based on multidimensional maps, is formulated to describe the operational characteristics of individual MES and aggregate DMES, including the role of multienergy networks in enabling or constraining flexibility. Several tutorial examples are finally presented with illustrative case studies on current and future DMES practical applications.
•Quantitative analysis of sector coupling scenarios.•Detailed modelling of integrated power and gas networks.•Quality tracking of distributed hydrogen blends in final users.•Dispatch and hydrogen ...injection strategies for higher integration of renewable energy.
Electricity and gas infrastructure coupling has the twofold effect of solving production-consumption mismatches and decarbonizing the natural gas system through power-to-gas technologies producing hydrogen to be injected within the gas network. However, little is known on how this may impact the gas network operation, especially at a local level. This paper aims to fill this gap by presenting a methodology for modeling the interactions between electricity and gas distribution networks through the implementation of their physical models. A scenario of increasing penetration of distributed photovoltaic production is considered for a sample urban area. Whenever photovoltaic production exceeds the urban area consumption, hydrogen is produced and injected into the gas network. 24 injection scenarios were examined and compared to evaluate their impacts on fluid-dynamics and the quality of gas blends. Results show possible bottlenecks against hydrogen injection caused by the gas network. During summertime operations and in the cases of injection following directly the solar over-production, the hydrogen share peaks 20–30% already in the scenario of 40% solar penetration, generating unacceptable blends. These gas quality perturbations are considerably reduced when hydrogen is injected constantly throughout the day. The choice of the injection node also contributes to perturbation reduction. Sector coupling through hydrogen blending results in a complex interplay between renewable energy excess and local gas network availability which can be enhanced by buffer storage solutions and proper choice of injection node. In the framework of integrated and multi-gas systems, combined simulation tools are necessary to evaluate sector-coupling opportunities case-by-case.
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