Article
Biodiversity Conservation
Manoela B. Lyra, Ricardo G. Bahia, Michel B. Jesionek, Rodrigo T. Carvalho, Fernando C. Moraes, Adele S. Harvey, Renato C. Pereira, Fabiano Salgueiro, Leonardo T. Salgado
Summary: The aim of this study was to elucidate the taxonomy of common but overlooked epiphytic coralline algae from the Abrolhos Archipelago in Brazil. Two thin epiphytic coralline species were recorded, including a new species of Lithophyllum and Hydrolithon farinosum. Molecular analysis confirmed the classification of the new Lithophyllum species and discussed the global distribution of Hydrolithon farinosum.
Article
Engineering, Marine
S. Ponce de Leon, C. Guedes Soares
Summary: This study examines the generation of extreme waves in the Agulhas Current Retroflection as a result of strong wave-current interaction. High-resolution simulations using two third-generation wave models were performed, considering ocean surface currents, for a period of two years and six months. The study utilized high-resolution SWAN nested grids and investigated the effects of surface current velocities of mesoscale eddies on surface wave properties and energy.
Article
Environmental Sciences
Reza Amir Ahmadi, Tooba Varasteh, Cynthia B. Silveira, Juline Walter, Eduardo Siegle, Claudia Omachi, Carlos Eduardo de Rezende, Ronaldo B. Francini-Filho, Cristiane Thompson, Diogo Tschoeke, Laura Bahiense, Fabiano L. Thompson
Summary: Microbes play a key role in coral reef health, but the importance of physical-chemical and biological processes in controlling microbial biomass is unclear. By analyzing a large dataset, machine learning models identified hydrodynamic forcing, Dissolved Organic Carbon (DOC), and Total Nitrogen (TN) as the most important predictors of microbial abundance in the water of Abrolhos reefs. Higher temperatures, longer seawater residence time, higher nutrient concentration, and lower coral and fish biomass in coastal reefs may lead to higher microbial abundance, potentially impacting coral resilience against stressors.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Oceanography
Igor Uchoa, Iury T. Simoes-Sousa, Ilson C. A. da Silveira
Summary: This study characterizes the variability of mesoscale eddies in the Brazil Current, finding that their formation is correlated with seasons and geographic locations. The Vitoria, Cape Sao Tome, and Cape Frio Eddies are important features of these eddies. The study also reveals that while most eddies are considered quasi-stationary, the Vitoria, Cape Sao Tome, and Cape Frio Eddies can detach and migrate off the mean current axis.
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS
(2023)
Article
Environmental Sciences
Remi Laxenaire, Eric P. Chassignet, Dmitry S. Dukhovskoy, Steven L. Morey
Summary: This study investigates the processes controlling the dynamics of the Loop Current (LC) in the Gulf of Mexico (GoM) and highlights the importance of realistic flow variability for accurate simulation of the LC system. The results show that the duration and behavior of the LC are influenced by the intensity and direction of the flow through the Yucatan Channel, as well as the presence of anticyclonic eddies.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Green & Sustainable Science & Technology
Lav Kumar Gupta, Manish Pandey, P. Anand Raj
Summary: This paper studies the numerical modeling of scour depth near a rectangular spur dike using the RNG turbulence model and sedimentary van Rijn model with nested mesh configuration. The study also compares three turbulence models, RNG, k-ε, and LES, for estimating scour depth and evaluating temporal variation. The results show that the LES model overpredicts scour depth compared to k-ε and RNG models, and increasing the bed load coefficient near the spur dike increases scour depth. The simulated results agree well with experimental results within a 5% error for sediment elevation and scour depth.
CLEAN-SOIL AIR WATER
(2023)
Article
Geosciences, Multidisciplinary
Kaili Zhang, Zheng Gong, Kun Zhao, Keyu Wang, Siqi Pan, Giovanni Coco
Summary: The study investigates the stability of overhanging riverbanks through laboratory experiments and numerical simulations. Results show that flow infiltration leads to decreased soil shear strength and shear failure. The distance of the failure surface can be characterized by twice the width of the overhanging block.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2021)
Article
Geography, Physical
Fernanda V. Vieira, Alex C. Bastos, Valeria S. Quaresma
Summary: Submarine geomorphology is a main environmental driver defining the seascape and associated benthic habitat. This study examines the morphology and associated habitats of submerged reefs and inter-reef areas near Abrolhos island in Brazil, discussing the evidence of reef drowning and sea-level/climate events. The results show the presence of distinct reef clusters and different benthic habitats formed during different sea-level rise periods, indicating the importance of submarine geomorphology in understanding sea-level changes.
Article
Environmental Sciences
Corentin Subirade, Pierre L'Hegaret, Sabrina Speich, Remi Laxenaire, Johannes Karstensen, Xavier Carton
Summary: Using high-resolution in-situ observations and satellite altimetry, researchers have identified the key role played by North Brazil Current rings in Atlantic Ocean circulation and climate. They also discovered a more complex structure than previously known, including the impact of the Amazon outflow in creating a barrier layer.
Article
Engineering, Geological
Teng-Fei Fu, Tao Xu, Michael J. Heap, Philip G. Meredith, Tian-hong Yang, Thomas M. Mitchell, Yoshitaka Nara
Summary: Understanding the physics of water imbibition into initially unsaturated sandstone is crucial for displacement processes and fluid transport in the vadose zone. Utilizing NMR technology, researchers visualized and quantified the dynamics of water infiltration and distribution in the sandstone. The study also involved developing an analytic function to estimate sandstone moisture profile and incorporating a three-dimensional discrete element grain-based model to simulate water imbibition process and evaluate its impact on mechanical properties of sandstone.
ENGINEERING GEOLOGY
(2021)
Article
Environmental Sciences
Cesar B. Rocha, Iury T. Simoes-Sousa
Summary: Recent studies show that the South Brazil Bight hosts strong westward propagating mesoscale eddies, with most of the observed eddy kinetic energy (EKE) being generated by local eddies, while remote eddies contribute minimally.
Article
Environmental Sciences
Lingjing Xu, Dezhou Yang, Xingru Feng, Junchuan Sun, Guandong Gao, Xuan Cui, Baoshu Yin
Summary: The Kuroshio Current is an important source of nutrients for the East China Sea (ECS) due to the large amount of nutrients it carries. The influence of mesoscale eddies on the Kuroshio nutrient input into the ECS is unknown. A hydrodynamic model with constructed cyclonic and anticyclonic eddies is used to explore this influence. The results show that cyclonic eddies reduce on-shelf phosphate flux, while anticyclonic eddies increase Kuroshio phosphate input to the ECS.
FRONTIERS IN MARINE SCIENCE
(2023)
Review
Oceanography
Ilson C. A. da Silveira, Filipe Pereira, Glenn R. Flierl, Iury T. Simoes-Sousa, Andre Paloczy, Milton Borges-Silva, Cesar B. Rocha
Summary: The most conspicuous oceanographic features off Southeast Brazil are the quasi-stationary eddies formed off Capes Sao Tome (CSTE) and Frio (CFE) associated with the Brazil Current (BC). These eddies have an average growth rate of 0.06 day-1 and almost no propagation speeds. CFE tends to be more unstable and frequent than CSTE (3.5 vs. 2.3 events per year), with CSTE able to propagate north or south while CFE only propagating southward.
PROGRESS IN OCEANOGRAPHY
(2023)
Article
Geosciences, Multidisciplinary
Rodolfo Jose Angulo, Maria Cristina de Souza, Maria Luiza Correa da Camara Rosa, Eduardo G. Barboza, Guilherme Camargo Lessa, Luiz Carlos Ruiz Pessenda, Augusto Luiz Ferreira Junior
Summary: This study presents spatiotemporal paleo-sea-level reconstructions from Abrolhos archipelago and Abrolhos Bank, filling in a 500 km coastline gap. The data indicates sea levels up to 2.9 m higher than the current one between the Mid- to Late Holocene. There was little hydroisostatic compensation across the continental shelf between the archipelago and the mainland coast.
Article
Oceanography
Maria Laura Zoffoli, Robert Frouin, Rodrigo L. Moura, Thais Andrade Galva de Medeiros, Alex C. Bastos, Milton Kampel
Summary: Managers and scientists can benefit from satellite-derived bottom type maps of coral reefs. In this study, a map of the coral reefs within the Abrolhos National Marine Park was generated using a high-resolution image and field observations. The map can guide management strategies, provide a background for connectivity studies, and help address the evolution of the unique reef structures.
CONTINENTAL SHELF RESEARCH
(2022)
Article
Fisheries
Ana Cristina Teixeira Bonecker, Mario Katsuragawa, Marcia Salustiano de Castro, Claudia Namiki, Maria de Lourdes Zani-Teixeira, Igor Uchoa Farias, Ilson Carlos Almeida da Silveira
JOURNAL OF APPLIED ICHTHYOLOGY
(2019)
Article
Geochemistry & Geophysics
Filipe Pereira, Ilson C. A. da Silveira, Glenn R. Flierl, Amit Tandon
DYNAMICS OF ATMOSPHERES AND OCEANS
(2019)
Article
Oceanography
Wilton Z. Arruda, Ilson C. A. da Silveira
CONTINENTAL SHELF RESEARCH
(2019)
Article
Oceanography
Dante C. Napolitano, Ilson C. A. da Silveira, Cesar B. Rocha, Glenn R. Flierl, Paulo H. R. Calil, Renato P. Martins
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2019)
Article
Oceanography
Caue Z. Lazaneo, Dante C. Napolitano, Ilson C. A. da Silveira, Amit Tandon, Daniel G. MacDonald, Rafael A. Avila, Paulo H. R. Calil
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2020)
Article
Meteorology & Atmospheric Sciences
Ana Paula Morais Krelling, Avijit Gangopadhyay, Ilson da Silveira, Felipe Vilela-Silva
Summary: This study develops the key elements of a Feature-oriented regional modelling system in the Western Equatorial Atlantic, showing its potential applicability for operational forecasts and process studies. Through numerical experiments, it is found that the Potiguar Eddy can be generated by the North Brazil Undercurrent, with the induced vertical shear from the Deep Western Boundary Current affecting the eddy's characteristics.
JOURNAL OF OPERATIONAL OCEANOGRAPHY
(2022)
Article
Remote Sensing
F. Pereira, M. Bouali, P. S. Polito, I. C. A. da Silveira, R. N. Candella
REMOTE SENSING LETTERS
(2020)
Article
Oceanography
Ana P. M. Krelling, Ilson C. A. da Silveira, Paulo S. Polito, Avijit Gangopadhyay, Renato P. Martins, Jose Antonio M. Lima, Fernando de O. Marin
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2020)
Article
Oceanography
Dante C. Napolitano, Cesar B. Rocha, Ilson C. A. da Silveira, Iury T. Simoes-Sousa, Glenn R. Flierl
Summary: The Brazil Current meanders cyclonically within Tubarao Bight, occasionally forming the Vitoria Eddy, influenced by the Intermediate Western Boundary Current recirculating within the bight. A simple two-layer quasi-geostrophic model was used to study the effects of IWBC recirculation on BC meandering and Vitoria Eddy formation, showing that the strength of BC upstream of Tubarao Bight affects the formation of the eddy. The model experiments demonstrated that the interaction between the upper-layer jet and the lower-layer eddy plays a key role in triggering downstream meander growth and cyclone formation.
Article
Oceanography
D. C. Napolitano, I. C. A. da Silveira, A. Tandon, P. H. R. Calil
Summary: The Brazil Current and the Intermediate Western Boundary Current interact with the Vitoria-Trindade Ridge at 20.5 degrees S, generating mesoscale variability and unaddressed submesoscale dynamics. New observations and a high-resolution model are used to analyze the role of the VTR seamounts in the regional submesoscale dynamics, revealing submesoscale instabilities and flow-topography interactions. The lack of observations remains the main obstacle to better understand submesoscale processes in the oligotrophic South Atlantic where the VTR emerges as a submesoscale hotspot.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Oceanography
C. D. Luko, I. C. A. da Silveira, I. T. Simoes-Sousa, J. M. Araujo, A. Tandon
Summary: The southern branch of the South Equatorial Current is the northern limit of the South Atlantic Subtropical Gyre, bifurcating into the Brazil Current and North Brazil Undercurrent when it reaches Brazil. This study shows that the South Equatorial Current arrives at the South Atlantic western boundary as a multi-banded flow with different subsurface cores, influencing the seasonality of the Brazil Current and mesoscale eddies off Brazil.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Oceanography
C. Z. Lazaneo, P. H. R. Calil, A. Tandon, I. C. A. da Silveira
Summary: Mesoscale eddies in the South Atlantic propagate westward and interact with the Vitoria-Trindade Ridge, leading to the formation of submesoscale coherent vortices (SCVs). The dynamics of two adjacent SCVs wandering through the ridge are described using high-resolution measurements. It is found that the anticyclonic SCVs exhibit low potential vorticity and angular momentum, and are prone to small-scale turbulence and energy dissipation.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Iury T. Simoes-Sousa, Ilson Carlos A. Silveira, Amit Tandon, Glenn R. Flierl, Cesar H. A. Ribeiro, Renato P. Martins
Summary: This study explores the Barreirinhas Eddies, submesoscale vortices generated by the North Brazil Current, which occur independently at different depths with incredibly high Rossby Numbers. Analysis suggests that the increased stability of these eddies is due to the joint effect of strong winds, stratification, proximity to the equator, and topography.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Environmental Sciences
Luigi Jovane, James R. Hein, Isobel A. Yeo, Mariana Benites, Natascha M. Bergo, Paulo V. F. Correa, Daniel M. Couto, Ayrton D. Guimaraes, Sarah A. Howarth, Henrique R. Miguel, Kira L. Mizell, Denise S. Moura, Francisco L. Vicentini Neto, Mayza Pompeu, Ianco M. M. Rodrigues, Frederico R. Santana, Pedro F. Serrao, Tomas E. Silva, Pedro M. Tura, Carolina L. Viscarra, Mateus G. Chuqui, Vivian H. Pellizari, Camila N. Signori, Ilson C. A. Da Silveira, Paulo Y. G. Sumida, Bramley J. Murton, Frederico P. Brandini
FRONTIERS IN MARINE SCIENCE
(2019)
Article
Physics, Fluids & Plasmas
Paulo H. R. Calil, Nobuhiro Suzuki, Burkard Baschek, Ilson C. A. da Silveira
Summary: The study investigates the dynamics of meso- and submesoscale features in the northern South Brazil Bight shelf region using a regional model with 500-m horizontal resolution. Focus is on the Cabo Frio upwelling center, where nutrient-rich coastal waters are transported into the mid- and outer shelf, impacting local and remote productivity. During the upwelling phase, an intense front with strong horizontal temperature gradients and surface-intensified frontal jet develop, creating a preferential cross-shelf transport pathway.
Article
Oceanography
Alyssa M. LeClaire, Eric N. Powell, Roger Mann, Kathleen M. Hemeon, Sara M. Pace, Vincent Saba, Hubert du Pontavice, Jillian R. Sower
Summary: Arctica islandica is an important species for recording climate change on the U.S. northeast continental shelf, and its growth rates show synchronous changes with cold and warm climatic periods. This study finds that A. islandica near the Delmarva Peninsula had higher growth rates during cold periods, possibly due to increased food supply in shallower water. The range recession of this species is a long-term process determined by the survivorship of older individuals.
CONTINENTAL SHELF RESEARCH
(2024)
