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Repositório Científico da UAlg
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Cyclonic surface circulation in the northern coast of the Gulf of Cádiz: insights from Lagrangian drifters and high-resolution models
Publication . Luján-Amoraga, Esther; Román-Cascón, Carlos; Jiménez Rincón, Juan Alberto; Izquierdo, Alfredo; Bruno, Miguel; Vázquez, Águeda; Relvas, Paulo; Garel, Erwan; Bolado-Penagos, Marina
This study presents direct in situ observational evidence of a cyclonic circulation cell east of Cape Santa María (CSM), in the northern Gulf of Cádiz (GoC). Three Lagrangian drifters deployed in October 2022 revealed a coherent cyclonic circulation cell with a characteristic diameter of approximately 40-45 km, consistently estimated from drifter trajectories and relative vorticity. Their trajectories showed alternating eastward and westward flows, modulated by wind variability, bathymetry, and mesoscale dynamics. Satellite observations showed a cooler, chlorophyll-a enriched core, consistent with upwelling and retention of enriched surface water masses within the circulation cell.
High-resolution WRF atmospheric simulations indicated alternating easterly and westerly wind regimes that were associated with reversals in coastal circulation. Westerly winds between 18th and 24th October produced positive Ekman pumping east of CSM, creating conditions favourable to the intensification of cyclonic circulation. The IBI ocean model reproduced the main structure of the circulation cell structure, including flow accelerations near the shelf edge, and indicated upward vertical motions within the cyclonic circulation cell.
A Lagrangian particle experiment suggested that the cyclonic cell favours both retention and offshore export of surface waters, with residence times of up to approximately 16 days. Overall, this study highlights the role of interactions between atmospheric forcing, bathymetry, and mesoscale dynamics in controlling small-scale surface circulation in the GoC, and underscores the value of integrating drifter observations, satellite data, and numerical models to characterize coastal dynamics.
Polar marine biocorrosion and biofouling processes mediated by the trimeric autotransporter adhesin of Psychrobacter cibarius
Publication . Wang, Xiaoyu; Mao, Xiaomin; Wang, Yuyi; Peng, Lihua; Yang, Jin-Long; Liu, Tao; Power, Deborah Mary; Guo, Na; Liang, Xiao
Polar oceans, a critical frontier for global resource development and strategic competition, impose extreme challenges on marine engineering materials. Among these, the combined effects of corrosion and fouling by bacterial biofilms are the major biotic factors accelerating material deterioration; yet, the molecular mechanisms by which polar marine bacteria drive these processes remain poorly understood. Using Psychrobacter, a dominant bacterial genus in polar marine environments, we explored the characteristics and mechanisms of both biofouling and biocorrosion induced by the biofilm of Psychrobacter cibarius. Here, we show that biofilms formed by the polar bacterium P. cibarius induce significantly more severe corrosion of cryogenic steel (EH40) and promote higher settlement and metamorphosis of the typical macrofouling mussel larvae than biofilms of the temperate species Pseudoalteromonas marina. Biofilms of P. cibarius contained higher levels of extracellular proteins, which correlated with higher biocorrosion and biofouling activity. Comparative genomics identified genes encoding a trimeric autotransporter adhesin (YadA), a unique extracellular protein present in P. cibarius but absent from P. marina. Deletion of the membrane-anchoring region of YadA abolished bacterium-surface fibrillar structures, markedly reduced bacterial adhesion, decreased extracellular protein secretion within the biofilm, and significantly suppressed both electrochemical corrosion and mussel larval settlement and metamorphosis. These findings demonstrate that the YadA adhesin is a key determinant of P. cibarius biofilmmediated biocorrosion and biofouling under polar marine conditions. This study provides a new direction for both biocorrosion and biofouling control in polar marine environments and a basis for developing adhesintargeted protective materials.
A guide to support the integration of marine protected areas into maritime spatial planning
Publication . Calado, Helena; Markovic, Marina; Dias Gois Rodrigues de Queiroz, Joyce; Gutierrez, Débora; Pegorelli, Camila; Santos, Catarina Frazão
Marine protected areas can contribute to achieving biodiversity targets, especially when embedded in maritime spatial planning (MSP). Drawing on a screening of European MSP, this work presents a framework spanning pre-planning, planning and implementation. At each stage, it combines Strategic Environmental Assessment, a Criteria Checklist, and Strategic Recommendations to align conservation objectives, blue-economy activities and the rights and needs of coastal communities, supporting a more just, healthy and productive ocean.
A cyberattack detection and mitigation framework for community-based microgrids
Publication . Velarde, P.; Zafra-Cabeza, A.; Santos, Joni; Monteiro, Jânio; Bordons, C.
This article presents a Model Predictive Control approach aimed at enhancing the resilience of community-based microgrids against cyberattacks, using the energy community of Culatra Island, located in Algarve- Portugal, as a case study. Additionally, this work incorporates cybersecurity measures designed to detect and mitigate various types of cyberattacks. By applying residual analysis, the control system is able to identify anomalies in key parameters such as power balance and battery state of charge, which allows for the implementation of targeted mitigation strategies. The results demonstrate the effectiveness of the system in maintaining stability and operational resilience under different attack scenarios. Index Terms— microgrid, model predictive control, energy community, cyberattacks.
Final report on digital innovation and implementation
Publication . Pinto da Costa, José Carlos
The primary objective of this report is to present the acquired synthesis of the existing knowledge in digital innovation and implementation of Smart Healthy Age-Friendly Environments (SHAFE) solutions, a critical assessment of practices, and recommendations for the future, in line with the objectives defined for the Working Group 3 of NET4Age-Friendly:
1. Map the state-of-the-art on digital solutions and large-scale sustainable implementation examples enabling SHAFE, through the collation and analysis of existing initiatives, practices implemented and related projects.
2. Collect and analyse former and ongoing research/practices on digital solutions and large-scale implementation and publish such collection in the form of a searchable knowledge base on the Action website (www.net4age.eu).
3. Synthesize and improve the state-of-the-art and good practices through a detailed analysis and the development of recommendations for the future.
The objectives were achieved departing from a comprehensive desk research to address the background and challenges, define scope and purpose, identify target stakeholders, analyse the existing knowledge base, and augment it with new data, thereby contributing significantly to the further development of the framework’s Module on digital innovations and implementation.
Based on these findings, the report aims to offer a nuanced understanding of the current digital landscape and tailored approaches that align with the evolving dynamics of technological advancements in the SHAFE areas. Through these insights, it delivers a comprehensive and forward-looking resource in the sphere of digital innovations and implementation towards the promotion of more inclusive communities.